Pre-Feasibility
Studies for

IMPLEMENTATION OF

GREEN BRICKPRODUCTION

TARA

Government of Assam
Environment & Forest

Pre-Feasibility Studies for Implementation of Green Brick Production | iAuthors
Dr. Soumen Maity (TARA)
Debaprasad Das (TARA)
Mohak Gupta (TARA)
Rashi (TARA)

Contributors
Shri M. K. Yadava, IFS, PCCF & HoFF, Forest Department of Assam
Shri K.S.P.V. Pavan Kumar, IFS, Addl. PCCF (HQ)
Shri Anurag Singh, IFS, CCF (Legal and Climate Change), CEO-ACCMS
Shri Rizwan Uz Zaman, Technical Consultant, ACCMS
Mr. Arindam Goswami, RA-II, ACCMS
Smt. Priyanka Borah, SRF, ACCMS

EditorUrvashi Yadav (TARA)

B-32, TARA Crescent, Qutab Institutional Area
New Delhi -110016. India.
Email: mail@devalt.org
Website: www.devalt.org
Ph.: 011-2654-4100, 011-2654-4200

DISCLAIMER: The views expressed in this report do not necessarily reflect the views of Assam
Climate Change Management Society, Govt of Assam. The Society also does not guarantee theaccuracy of any data included in this publication nor does it accept any responsibility for theconsequences of its use. All the content or information present here is the exclusive property of
Assam Climate Change Management Society (ACCMS), Govt of Assam. The information contained
here is correct at the time of publishing. The views expressed in this report do not necessarily reflect
the views of any organisation(s) associated with ACCMS or TARA.
COPYRIGHT: No material from this document may be copied, modified, reproduced, republished,uploaded, transmitted, posted or distributed in any form without prior written permission from
ACCMS. Unauthorised use of the information appearing here may violate copyright, trademark &other applicable laws and could result in criminal or civil penalties.

© Assam Climate Change Management Society, Govt of Assam 2022
ii | Pre-Feasibility Studies for Implementation of Green Brick Production

Acknowledgement
It would not have been possible for the project team of Technology and Action for Rural Advancement(TARA), Development Alternatives Group, to undertake the pre-feasibility study to introduce greener
brick making technologies in Assam without the active involvement and assistance of a number ofindividuals and organisations.
The Feasibility Study team would, in particular, like to acknowledge the unflinching support given by all
the staff and management of Assam Climate Change Management Society (ACCMS), Guwahati, Govt ofAssam. We would like to express our sincere thanks to Rizwan Uz Zaman whose constant support andconstructive criticism of the work helped in refining the results. Thanks are also due to K.S.P.V. Pavan
Kumar, I.F.S., Addl. Principal Chief Conservator Of Forests (Biodiversity & Climate change) for helping
in getting data and resolving crisis points. Thanks are also due to Arindam Goswami for supporting us
beyond means to undertake the pre-feasibility study. Their constant aspiration of supporting Assamto explore efficient brick production inspired the team to achieve the same.
The team gratefully acknowledges the support from Pollution Control Board Assam for their interest
shown in the pre-feasibility study. Their interest to take out time, compile and provide brick kiln
data and discuss possible means of cooperation with the implementation team shows their keeninterest and support for dissemination of the cleaner brick production technologies in Assam. Their
constructive criticism of the results and feedback on future work to be done through discussions was
extremely helpful.
At the end and certainly not because they were the least important, TARA would like to highlight the
crucial role played by brick manufacturers of Assam in helping us understand the current situation,
identify key issues, estimate the immense potential for modernization of the brick sector and chartout the way forward. The openness and alacrity with which they shared information and ideas wastruly remarkable.
We do hope that the feasibility study will encourage the introduction of Cleaner Brick Production
Technologies in Assam to help in building up resilience to cope with climate change effects in future.

Technology and Action for Rural Advancement, 2022

Pre-Feasibility Studies for Implementation of Green Brick Production | iii

Contents

Acknowledgementiii

Executive Summary

ix

1
2
3
4
5
6
7

Introduction

1

1.1

Context1

1.2

Current challenges

2

1.3

Need for assessment

2

1.4

Project objectives

5

Research Design and Methodology

7

2.1

Phase I: Inception

8

2.2

Phase II: Research and Analysis

9

2.3

Phase III: Consultation and Documentation

10

2.4

Challenges and Limitations

10

Research Findings

11

3.1

Socio-ecological profile

12

3.2

Overview of brick production in Assam

21

Resource and emissions

51

4.1

Soil usage

52

4.2

Emissions in the brick sector of Assam

53

Alternative technology options

57

5.1

Identified alternative materials and technologies

58

5.2

Alternate clay brick firing technologies

61

5.3

Comparative analysis of alternative technologies

76

5.4

Scenario building for GHG emissions

80

5.5

Summary82

5.6

Enabling access to finance for transitioning to Green Brick production

83

Conclusions, Recommendations and way forward

87

6.1

Approach for sectoral transformation

87

6.2

Recommendations and way forward

89

ANNEXURES95

ANNEXURE 1 – Baseline Assessment Framework

96

ANNEXURE 2 – Impact Assessment Matrix

98

ANNEXURE 3 – Characteristics of coal usage

100

ANNEXURE 4 – Compressed Earth Block Technology Business Plan Details

101

ANNEXURE 5 – Conversion of FCBTK to Zig zag Kiln Technology
Business Plan Details

109

ANNEXURE 6 – VSBK Business Plan Details

121

ANNEXURE 7 – Greening of Brick Industry in Assam | Proposal for introducing
energy efficient, low carbon burnt brick production technologies 137
ANNEXURE 8 – Brick Lab Testing Reports and Soil Testing Reports

148

ANNEXURE 9 – Ministry of Environment, Forest and Climate
Change Notification, 2022

178

iv | Pre-Feasibility Studies for Implementation of Green Brick Production

List of Figures
Figure 1

District Map and location of the three demand centres - Guwahati, Silchar, and Dibrugarh.12

Figure 2

Climatic data for Assam state (WorldData, 2020)

13

Figure 3

Economic profile of Assam

15

Figure 4

Tectonic mapping of North East

16

Figure 5

Geological and Mineral map of Assam

17

Figure 6

Soil Map of Assam

19

Figure 7

Zoning of Building Material Production

20

Figure 8

Availability of agriculture produce and biomass in Assam

21

Figure 9

Map of Brick Kilns in Guwahati

24

Figure 10

Map of brick kilns in Silchar

24

Figure 11

Map of brick kilns in Dibrugarh 

24

Figure 12

X-ray diffraction analysis of soils from Guwahati, Silchar and Dibrugarh

25

Figure 13

Different kilns from the demand centres. Semi-covered kiln design such as the one
observed in Silchar (centre) allows for brick production during adverse weather
conditions 

26

Figure 14

Steps of brick-making process. 

28

Figure 15

Excavation of soil using earth movers

29

Figure 16

Deep excavation of soil leaves behind barren land (bottom). 

29

Figure 17

Semi-mechanised equipment such as pug mills can be seen being used at kilns for
mixing soil. 

30

Figure 18

Mixing of soil using tractor operated pugmill. 

31

Figure 19

Brick moulding by hand in process. 

31

Figure 20

Design of mould for brick making. 

32

Figure 21

Automatic movable brick extrusion machine

33

Figure 22

Mechanised extrusion process. 

34

Figure 23

Different stacking patterns during brick drying phase (left and right). 

34

Figure 24

Unfired brick transportation methods - on cycles, wheelbarrows and manual carriage. 

35

Figure 25

Brick stacking patterns during firing – FCBTK (top) and zigzag kiln (bottom). 

36

Figure 26

Brick firing in process. 

37

Figure 27

Stacking of fired bricks. 

37

Figure 28

Types of fuel used for the firing of the bricks and it’s mapping38

Figure 29

Coal crusher machine in Silchar. 

39

Figure 30

Timber stored for firing initiation. 

40

Figure 31

Estimated CO2 emissions for study areas

41

Figure 32

Map showing migration of moulders and firemen43Figure 33 a

Land use pattern by brick kilns

52

Figure 33 b

Growth of brick kilns and area of land consumed by the kilns.

53

Figure 33 c

Graph depicting projected estimate of GHG emissions.

53

Figure 34

High draught Zigzag Kiln

61

Figure 35

Firing of bricks in high draught Zigzag kiln

62

Figure 36

Stacking of unfired bricks before firing

62

Figure 37

Air flow through high draught kilns

63
Pre-Feasibility Studies for Implementation of Green Brick Production | v

Figure 38

Natural draught Zigzag Kiln

63

Figure 39

Hoffman Kiln

65

Figure 40

Detailed plan of Hoffman kiln

66

Figure 41

Firing process in Hoffman Kiln

66

Figure 42

Process of controlling excess air67

Figure 43

Features of Hoffman Kilns

67

Figure 44

Operating mechanism of down draft kiln

69

Figure 45

Chamber kiln

70

Figure 46

Design of chamber kiln

70

Figure 47

Tunnel Kiln

71

Figure 48

Vertical shaft brick kiln

72

Figure 49

Working principle of VSBK

73

Figure 50

Location of brick kilns operating in Bihar as of year 2022

74

Figure 51

Graph depicting projected estimate of GHG emission under scenario 1 i.e. if present
brick manufacturing continues using FCBTK.
Graph depicting projected estimate of GHG emission under scenario 2 i.e. if present
brick manufacturing is completely replaced by CEBGraph depicting projected estimate of GHG emission under scenario 3 i.e. if present
brick manufacturing through FCBTK undergoes gradual and partial conversion with
zig zag kiln.
Graph depicting projected estimate of GHG emission under scenario 4 i.e. if present
brick manufacturing through FCBTK undergoes gradual and partial conversion
with VSBK.
Graph depicting projected estimate of GHG emission under scenario 5 i.e. if present
brick manufacturing through FCBTK undergoes gradual and partial conversion
with CEB.

Figure 52
Figure 53

Figure 54

Figure 55

80
80

81

81

82

List of Tables
Table 1

District level climate projections of Assam for 2021-2050

4

Table 2

Annual temperature variations across demand centres

13

Table 3

Demographic Profile of Assam (Census 2011)

14

Table 4

List of brick kilns as received from PCBA

22

Table 5

Details of kilns surveyed

23

Table 6Sieve analysis of brick making soils in priority areas

25

Table 7

Average annual brick production in demand centres

27

Table 8

Brick parameters as per lab test results

27

Table 9

Region-wise distribution of average annual consumption

40

Table 10 Coal quality in Assam

42

Table 11 Specific Energy Consumption for fired bricks

42

Table 12 Wages for different processes in brick making

44-45

Table 13 Estimated production cost for bricks

45

Table 14 GHG emissions in the brick sector of Assam

54

Table 15 Gaseous emissions in the brick sector of Assam

55

Table 16 District wise classification of kilns operational in Bihar as of 202275

Table 17 Decision making matrix

77

vi | Pre-Feasibility Studies for Implementation of Green Brick Production

List of abbreviations
ACCMS

Assam Climate Change Management Society, Govt. of Assam

BEE

Bureau of Energy Efficiency

CBRI

Central Building Research Institute

CGTMSE

Credit Guarantee Trust for Micro and Small Enterprises

CLCS-TU

Credit Linked Capital Subsidy for Technology Upgradation

CO

Carbon monoxide

CO2

Carbon dioxide

CTE

Consent to Establish

CTO

Consent to Operate

ECBC

Energy Conservation Building CodeFCBTKFixed Chimney Bull’s Trench Kiln

GSDP

Gross State Domestic Product

GDP

Gross Domestic Product

GHG

Greenhouse gas

HD

High Draught

KVIC

Khadi and Village Industries Commission

LM

Lean manufacturing

MCs

Mini clusters

MFI

Micro Finance institutions

MSECDP

Micro and Small Enterprises- Cluster Development Programme

MSME

Micro, Small and Medium Enterprises

MT

Metric Ton

MUDRA

Micro Units Development & Refinance Agency Ltd.

MUNY

Mahila Udyam Nidhi Yojana

MioT

Million Ton

NBFCs

Non-banking finance corporations

NOx

Nitrogen oxide

OHS

Occupational health and safety

PMEGP

Pradhan Mantri Employment Guarantee Programmes

PPM

Parts Per Million

PCBA

Pollution Control Board Assam

RRB

Regional Rural Banks

SEC

Specific Energy Consumption

SIDBI

Small Industries Development Bank of India

SPM

Suspended Particulate Matter

SO₂

Sulphur dioxide

SDC

Swiss Agency for Development and Cooperation

UAM

Udyog Aadhar Memorandum

VSBK

Vertical Shaft Brick Kiln

ZED

Zero defect, zero effect

Pre-Feasibility Studies for Implementation of Green Brick Production | vii

viii | Pre-Feasibility Studies for Implementation of Green Brick Production

Executive
Summary

Pre-Feasibility Studies for Implementation of Green Brick Production | ix

The pre-feasibility study for green brick1 production in Assam looked at the current brickproduction practices and trends across three demand centres in Assam - Guwahati, Silchar
and Dibrugarh and assessed the prevailing challenges in adoption of green technologies
across different stages of the construction sector value chain in the state. A holistic systems
approach was selected as a framework for analysis. The recommendations derived from theon-ground analysis aim to serve as a guide for the different stakeholders involved in theconstruction and brick manufacturing sector of Assam.
In order to arrive at any climate resilient strategies or models, an accurate estimation of
the number and types of brick producing units in the state along with a holistic picture of
their emissions, pollutant sources, available resources, socio-economic and geographicallandscape is crucial to assess the overall environmental impact of the sector. Although somedata on the same exists with PCB Assam, the completeness and accuracy of the data needs
to be verified through a ground-truthing exercise. Until and unless actual data is recorded,
any conclusion remains an estimation only and will present an inaccurate picture of actual
brick production in the state.
This pre-feasibility study was conducted using a three stage action research based approach
using research tools such as documentation, field research, GIS-mapping and stakeholder
consultations. A detailed socio-ecological profile relevant to the sector was prepared for
Assam by conducting geological studies and soil studies and secondary research on various
socio-economic parameters. In addition, an overview of the trends and practices in the
brick production sector is also presented by analysing the production and consumption
patterns, environmental impact, social conditions and economics, regulatory frameworks,
and appropriate policy convergence. It highlights the prevalent technologies with respect totype of kilns, fuels, bricks in use and their implications for various climatic, social, economic,
and ecological parameters.
As observed during this study, among the current practices observed on ground, kilns mostin use are the Fixed Chimney Bull’s Trench Kiln (FCBTK) type along with some instances of
Zig Zag kilns. In the type of bricks observed, few Autoclaved Aerated Concrete (AAC) block
making units were observed in Guwahati, while fly ash brick units were scarce due tounavailability of fly ash in the vicinity.
Due to the inherent climatic conditions of Assam, the brick making period in the state islimited to around 6 months. The high humidity poses challenges for firing as bricks have highmoisture content, demanding consumption of large amounts of fuel and energy in the firing
process. There is also no scientific basis for brick production processes followed vis-a-vis
soil selection, use of internal fuels, proper use of moulds, moulding process, drying process
and even firing process. There are no standardised processes or protocols and the current
entrepreneurs are largely ignorant of the technical advances in brick making, continuing theirtraditional, often outdated technologies. It is evident that the prevailing brick production
technologies and processes being used by burnt brick manufacturers in Assam are highly
energy-intensive, resource-depleting and pollute the environment. Although the state
follows a 230mm x 110mm x 70mm standard brick size, the brick sizes actually produced
vary widely. Due to inherent soil conditions, the quality of bricks being produced is excellent.
However, there is an evident need for proper training, scientific inputs and technology
diffusion amongst the brick producing community to improve the quality and profitability ofbricks as well as mitigate the socio-environmental impacts of brick production.
As per data received from PCBA, around 1242 brick kilns are presently operational in Assam,
producing an excess of 37,260 lakh bricks and consuming 670,680 tons of coal per year.
The annual GHG emissions from the brick kilns in Assam is estimated to be approximately
1

Green Brick here refers to the brick production process which is low carbon, low emission and aims to be environmentally sustainable and ‘green’ in this respect.

x | Pre-Feasibility Studies for Implementation of Green Brick Production

20,69,357 (0.26 MioT) tCO2/year. It is estimated that if business as usual continues, the total
GHG emission from brick kilns will reach around 46.87 tons per year by 2030 and 193.60
tons per year by 2050. These insights into the resource consumption and emissions statusof Assam assume significance in the backdrop of climate change resilience by identifying
the extent of raw material extraction and different sources of pollution within the brickmanufacturing sector. These figures serve as a wakeup call to move to more efficientmethods of brick production to ensure conservation of natural resources and environmental
protection while minimising the impact on human health and wealth.
Considering the factors discussed above, some alternative technology options have been
recommended based on critical analysis of the economic and environmental feasibility ofdifferent types of kilns and fuels used in the production process. In this respect, it identifies
two major intervention areas to integrate alternative technologies. The first proposes a
strategy of process optimisation and improvement of existing technologies using better
feeding and firing practices, or incorporating internal fuel in the brick making process. The
alternative option could be adoption of new technologies by switching to more efficient kiln
designs, such as zigzag or vertical shaft brick kilns (VSBK), or alternative masonry materials
such as compressed earth blocks. The Ministry of Environment, Forest and Climate Change
has in its recent notification also suggested the phasing out of FCTBK kilns while promoting
zigzag or VSBK kiln type. A comparative analysis of projected GHG emissions from various
technology options has been presented to compare their GHG emission reduction potential
for assisting data-based decision making towards the choice of technologies. Further
recommendations have also been made towards various financial instruments available forfacilitating this transition and supporting entrepreneurs in the sector.
The way forward has been presented in the form of recommendations to streamline theadoption of green manufacturing practices in the brick sector of Assam including:•

GIS-based mapping, resource mapping of raw materials being used and detailed GHG
inventorization and environmental impact assessment of brick kilns•

Technological improvement through pilot demonstration of alternate technologies,
facilitated technology transfer, and training, capacity building and awareness generation
among stakeholders•

Structural transformation through enhanced policy and institutional support, businessand financial support, implementation support through ancillary service providers,contextualisation of technology, and human and social capital development

Pre-Feasibility Studies for Implementation of Green Brick Production | xi

xii | Pre-Feasibility Studies for Implementation of Green Brick Production

1

1.Introduction

Pre-Feasibility Studies for Implementation of Green Brick Production | 1

1.1 Context
In light of the increasing economic activity and growing levels of urbanisation in the state ofAssam, the demand for supporting housing and infrastructure has been rising steadily. Thishas given a boost to the state’s construction sector, which recorded an impressive compound
annual growth rate of 7.35% between 2011-12 and 2016-17. However, this rate of growth isstill lower than the national average of 11.2%.
In keeping with the State’s goals and projected vision for sustainable development, theconstruction sector has emerged as one of the biggest employment generators in Assam. This
growth, however, has also caused this sector to become a major contributor to greenhousegas emissions, causing carbon footprint to increase significantly throughout the building
and material life cycle.
Unlike developed countries where the majority share of GHG emissions comes from theenergy consumption during the built environment’s operation and maintenance, in India
the majority contribution (more than 80%) of the construction industry’s emissions comesfrom consumption and production of materials like cement, steel and bricks.
Within the construction sector, apart from the manufacture and use of cement, fired-brickproduction is the most polluting, both in terms of its emissions as well as its use of virginresources. Despite being the predominant emissions’ contributor, quantitative data on
direct emissions from the brick industry in India has not yet been quantified in an integrated
manner. Brick firing continues to use fossil fuels like coal. In addition, in its composition too,clay bricks utilise fertile top soil from agricultural lands. This adds to the climate challenges,
as according to the 2022 edition of the National Footprint and Biocapacity Accounts2, weare using an equivalent of 1.75 Earths to provide resources and absorb waste. This means
it now takes the Earth one year and nine months to regenerate what we use within a year.
Humanity uses more ecological resources and services than nature can regenerate due toruthless overfishing and overharvesting of forests and emitting more carbon dioxide into theatmosphere than forests can sequester. With the increasing focus on resource efficiency inconstruction activities, one of the major challenges is to adopt strategies to facilitate a shift
to greener building materials and practices while reducing the energy footprint of existingbuilding materials and technologies.
In line with the conventional red brick making practices seen in the country, the Assam bricksector is not different in any way, both from the resource and the emission point of view. Till
date there is no published data on the actual number of brick kilns in the state of Assam. As
per PCBA’s official figures, in 2012-2013 there were around 731 brick kilns in the state. Thesekilns produced around 5 billion bricks in a year and consumed around 15MioT of fertile soils
on account of raw materials used for brick making with emissions of over 4.5 MioT of CO2 in
the firing process.

2

Global footprint network_ www.footprintnetwork.org/our-work/ecological-footprint/

2 | Pre-Feasibility Studies for Implementation of Green Brick Production

1.2 Current challenges
The current practices for brick production in Assam are mostly based on the traditional Fixed
Chimney Bull’s Trench Kiln (FCBTK) design which has high energy consumption due to fossil
fuel use and inefficient resource utilisation. Sporadic instances of alternate technologies
such as high draught kilns and zigzag kilns have also been observed. However, these arelimited in number and are yet to be adopted at a large scale. Further, limited instancesof non-fired building materials were found, that too confined to hollow concrete blocks
and bricks. Possible solutions in such a scenario may be explored through new material
technologies which utilise secondary resources or alternate materials in the composition ofbricks such as fly ash, agricultural waste, plastics etc. It may also be feasible to investigate
process optimization strategies for redesigning kilns using improved models such as naturalor induced draught zigzag kilns, vertical shaft brick kilns (VSBK), or improving the combustion
process within the brick kiln using internal fuels.
In addition to the above, Assam’s brick sector also faces other challenges. These are1.

Impacts of high GHG emissions

2.

Use of virgin raw materials

3.

Lack of awareness on new technologies and skills to implement the same

4.

Lack of technology demonstration to build confidence amongst entrepreneurs on
the viability

5.

No inventory by the State on the number of brick kilns

6.

Substantial number of unauthorised brick kilns operating in the state with noregulations or monitoring

1.3 Need for assessment
1.3.1 Climate change vulnerability of AssamIn this context, Assam is positioned to be a contributor as well as a victim of climate change.
The climate change vulnerability of Assam arises from multiple factors. Chief among themis its location and geography within the North eastern Himalayas and the fact that the
Brahmaputra river flowing through it is a perennial river. This places Assam at the risk offrequent floods, droughts and rainfalls which get exacerbated by climate change induced
extreme weather events. These inevitably position brick manufacturing at the mercy ofclimate change since the raw materials and production processes of drying, firing, soil mixing
etc get restricted due to these eventualities.
Other than the projected GHG emissions and pollution from its production and firing in kilns,
the brick production sector and its related activities also add to natural resource depletion
with vast swathes of fertile topsoil getting extracted for moulding into bricks. This has severe
repercussions on agriculture, and the natural climate resilience provided by soil, since itaggravates the rate of soil erosion, soil and land degradation, groundwater levels and water
retention in soil, making the land more prone to harmful impact of extreme weather eventsin the face of climate change events such as floods and droughts.

Pre-Feasibility Studies for Implementation of Green Brick Production | 3

1.3.2 Long term impact and Climate Projections
According to the Assam State Action Plan on Climate Change (2015-2020), it is estimated that•

86% of Assam’s population thrives on agriculture and forest produce•

Since the last 60 years (1951-2010), the annual mean temperature in Assam has increased
by 0.59 degree celcius and the annual rainfall has decreased by -2.96/mm per year•

Incidents of floods are projected to increase by more than 25%•

mean average temperature is likely to rise by +1.7-2.2 degree celsius by mid- century
with respect to 1971-2000.(Table 1)

Table 1 below goes a step further and shows the district wise projected impact of climatechange in terms of likely variations across the parameters of mean temperature, annual
rainfall, extreme rainfall days, floods and drought weeks between the period of 2021-2050.
These have a direct impact on the study areas of Silchar (Southern Assam), Dibrugarh(Northeast Assam) and Guwahati (Western Assam) which are estimated to be impacted bythese parameters in the future.
Table 1: District level climate projections of Assam for 2021-2050
2021-2050 wrt BL

Remarks

Mean Temperaturel .7-2.0°C

All across Assam

Annual Rain fall

-5 to 5%

North western districts

5-10%

North Eastern districts

10-25%

Central, South Eastern
Districts

Extreme rainfall days

38%

Rainfall >25 to 150 mm

Drought weeks-25% to >75%

Southern districts show marginal
reduction in drought weeks but restof the district show an increase by
more than 75% wrt BL

FloodsStream flow <10% to>25%

Min in North East and Max
in Southern part of theState

Note: Adapted from Assam State Action Plan on Climate Change, 2015-2020, (51) by Department ofEnvironment and Forest, Government of Assam, India

In view of the above figures, it is clear that the intensity and frequency of climate change
induced extreme weather events will only increase in Assam over the next few decades.
This threatens the economic viability of any technological upgrades and therefore calls forclimate resilient strategies to be integrated into all development plans at state, district andlocal level, across all the various sectors.

1.3.3 Way forward
To facilitate the shift to cleaner and greener brick production, it is crucial to study the current
status and practices of the industry and identify potential focus areas for reform. Alternatematerials and technologies may then be proposed with a clear assessment of expected
benefits across environmental, social, and economic parameters along with future pathways
and anticipated financial and regulatory mechanisms required for enabling a smoothtransition to the new technologies.

4 | Pre-Feasibility Studies for Implementation of Green Brick Production

1.4 Project objectives
The major objectives of the project were to:•

Evaluate the geographical extent of existing practices in burnt clay brick sector in andaround the three largest cities of Assam, namely Guwahati, Silchar and Dibrugarh(termed as demand centres)•

Calculate the emissions and topsoil impacted due to current practices along with aprojection based on current rates of population growth in planned infrastructure till2030•

Carry out pre-feasibility studies to identify potential of shifts to cleaner production
methods and technologies in sites (around the identified demand centres) in the state•

Identify ‘Greener’ fuel alternatives (available in the state) that can potentially replace
wood or coal to fire the brick production process and indicate savings in emissions•

Make recommendations with respect to identified technologies, and fuel mix for cleaner
production and finance requirements for this shift•

Proposal development for three units and handholding to access any clean funds to
set-up green industry

Pre-Feasibility Studies for Implementation of Green Brick Production | 5

6 | Pre-Feasibility Studies for Implementation of Green Brick Production

2
2. Research design
and methodology

Pre-Feasibility Studies for Implementation of Green Brick Production | 7

The research strategy for the project was designed with an action research-based approachstructured in three phases as shown in the figure below. The three phases have been further
described in this section. Geographically the research was centred around three primary
brick demand centres namely Guwahati, Silchar, and Dibrugarh.

PHASE
I

PHASE
II

PHASE
III

Inception

Research &Analysis

Consultation &Documentation

Conducting
Meeting with
ACCMS forrealigning project
expectations andfinalising work plan

Baseline
assessment toestablish theparameters ofcurrent brickproduction in
Assam andidentify available
alternatives

Stakeholder
workshop for
discussion on
Draft Report andincorporating
recommendations
in final report.

Baseline
assessment
framework
development forassessing themultidimensional
impact of existing
brick production
technology in
AssamDevelopmentof Impact
Assessment
Matrix to identify
criteria for overallsuitability oftechnologies.

Field Data
Collection
for identified
technology options
as per Impact
Assessment matrix
Action Research
for testing fieldpotential of internalfuel technology
Developing
techno- economic
model forassessing economic
feasibility, policy
market features

2.1 Phase I: Inception
The foundation for the project was laid down in this phase. Orientation meetings were heldwith ACCMS to define the scope and expectations from the project and finalise the work
plan as per defined project activities and deliverables. Post the initial discussions; a Baseline
Assessment Framework was developed to establish the boundary conditions and critical
criteria for assessing the current status of the brick industry in the state. Further, an Impact
Assessment Matrix was developed to identify desired criteria for comparative analysis ofalternate technologies that would be proposed to replace current brick production practices.
The Baseline Assessment Framework and Impact Assessment Matrix have been attached as
Annexure 1 and Annexure 2 respectively.

8 | Pre-Feasibility Studies for Implementation of Green Brick Production

2.2 Phase II: Research and Analysis
This phase was initiated with desk research and review of secondary literature including
various government and institutional research reports, technical papers, guideline
documents, presentations, etc. An overall socio-ecological profiling of Assam was developed
through this exercise as well as a preliminary overview of the brick industry in the state.
Available resources and some alternative technologies were identified through desk
research.
This was followed by field research for which a research team visited brick kilns producing
fired red bricks in the three demand centres and collected data using a questionnairedeveloped on the basis of the Baseline Assessment Framework. Brick kilns were selectedusing a representative sampling approach based on identification of kiln clusters throughvisual surveying on Google maps. Physical surveys in the regions were conducted to compile
information on the actual number of brick kilns operating in identified clusters and thensemi-structured interviews were carried out at kilns for data collection using the prepared
questionnaire. After the physical surveys, further mapping was conducted using Google Earth
to identify more kilns within and around the visited clusters based on visual cues identifiablefrom satellite imagery. However, with meetings with Member Secretary PCBA and otherregional offices of PCBA at Nagaon, Dibrugarh, Bongaigaon etc. it was understood that the
number of brick kilns are much more than officially reported. Thus, PCBA was contacted
for giving the actual number of bricks kilns as per their record. Upon verbal discussion with
PCBA it was learnt that the actual number of operating brick kilns are more than 1400 ofwhich around 20% are unreported which are not in the books of PCBA.
Some units manufacturing other types of bricks such as fly ash blocks, AAC blocks (Aerated
Autoclaved Concrete), etc. were also surveyed.

2.2.1 Sample collection and testing:
Samples of bricks being produced and coal used for firing were collected from the surveyedkilns. Red fired brick samples were collected from 6 kilns in Guwahati, 7 kilns in Silchar, and3 kilns in Dibrugarh. Apart from red bricks, few samples of Fly Ash bricks and Autoclaved
Aerated Concrete (AAC) Blocks were also collected. Testing was carried out in local labs forthese samples including Dimension Test, Water Absorption Test, and Compressive Strength
Test.
Coal samples were also collected from 12 different sources including brick kilns in target
geographies and coal depots in Guwahati. These samples were tested for their calorific value
to understand the energy consumption and associated environmental impacts from coalsourced from different regions. The results from these tests have been presented in Table 8
in Section 5.

2.2.2 Action Research
Based on the desk and field research, techno-economic models were developed foralternative brick technologies. This helped in identifying appropriate technologies forapplication as replacement for the fired red bricks currently in use. This assessment has
been presented in Section 5.

Pre-Feasibility Studies for Implementation of Green Brick Production | 9

2.3 Phase III: Consultation and Documentation
In the final phase, the findings from the desk and field research were compiled andanalysed into a draft pre-feasibility assessment report. The results were shared with relevant
stakeholders including ACCMS, etc. and the final report was prepared based on the comments
and recommendations put forth in the consultations.

2.4 Challenges and Limitations
The overall implementation of the project and data collection was impacted by certain
challenges that have been listed below:•

Field visits to study sites were hindered at the scheduled times due to lockdown andrestrictions owing to the COVID 19 pandemic as well as slowing down of economic
activities and unavailability of kiln workers during the festival times (such as Durga Pujo
and Chhat Puja).

•

Exhaustive mapping and survey of all existing kilns in the identified demand centres
could not be conducted due to remoteness and unsafe locations of some kilns.

•

Hostile attitudes of workers at some kilns led to unwillingness to share information or
sharing inaccurate data.

•

The actual data of brick kilns were not received from PCBA on time to make a realistic
assessment as requested by TARA and Government of Assam.

10 | Pre-Feasibility Studies for Implementation of Green Brick Production

3

3. Research findings

Pre-Feasibility Studies for Implementation of Green Brick Production | 11

This chapter describes the findings based on the primary and secondary research conducted
as per the methodology described above. Detailed findings have been presented for thethree identified demand centres, that is Guwahati, Silchar and Dibrugarh.
The first section - ‘Socio-Ecological Profile’ - includes the various social, economic andecological parameters at the state level that influence the brick production and processes
used including climate and topography, demographic and economic aspects, as well as theavailability of resources and geology of the state.
The second section - ‘Overview of Brick Production’ - describes the current status of the brickindustry in Assam along with the actual brick production levels, technologies and processes
practised, consumption of resources, and various social, environmental and economic
impacts and other considerations around the same.
Figure 1:
District Map
and locationof the threedemand centres Guwahati, Silchar,and Dibrugarh.
(Source: Author)

3.1 Socio-ecological profile
3.1.1 Topography and climate of the statePhysiographically, Assam has three broad geographical domains. The first domain is theBrahmaputra valley referring to the vast alluvial plains of Brahmaputra valley covering North
Assam, including both Guwahati & Dibrugarh. Next is the Central Assam Hills which is the
hilly terrain in Central Assam comprising Mikir Hill in Karbi Anglong and North Cachar Hill
districts. Finally, the Barak valley area covers hilly and alluvial terrain in the south covering
the Cachar and Karimganj districts in the Barak (Surma) valley, including Silchar.
The climate of Assam is typically a ‘Tropical Monsoon Rainforest Climate’, with high levelsof humidity and heavy rainfall. Winters begin in November and last until February. The
overall climate through the year is moderate with warm summers and mild winters. Spring(March–April) and autumn (September–October) are usually pleasant with moderate rainfall
and temperature. The levels of precipitation and number of rainy days are highest during
May to August due to the south-west monsoons gaining momentum in June which is theprimary rainy season. This period of high humidity extends to November. The continuous
high humidity persists almost throughout the year causing unpleasant weather conditions.
The combination of rainfall and high humidity creates sub-optimal conditions for brickproduction activities for a large part of the year, since excavation of availability of suitablesoil as well as the brick making process gets hampered.

12 | Pre-Feasibility Studies for Implementation of Green Brick Production

Table 2: Annual temperature variations across demand centres (in °C)
Average
Temperatures

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Guwahati

17.6

20.2

23.9

25.1

26.1

27.3

27.5

27.7

27

25.3

22

18.9

SiLehar

17.5

20

23.3

25.3

26.3

27

27.1

27.2

26.8

25.3

21.8

18.6

Dibrugarh

17

18.9

21.4

23.3

25.8

27.4

27.6

28

27.4

25.4

21.7

18.3

(Source: Climate Data, 2019)

There are some regional characteristics of the demand centres with respect to climaticconditions. Guwahati belongs to the Kamrup district in west-central Assam which has highrainfall and foggy winters. Winters last from December to February while there are chancesof thunderstorms and sandstorms between March and May. Late June to late September
comprises the monsoon time and pre-monsoon conditions last till November. Silchar,lying in Cachar District in south-central Assam, experiences heavy rainfall, high humidity
and moderate temperatures. Finally, Dibrugarh, belonging to the Dibrugarh district in east
Assam, reaches its highest temperatures during the south-west monsoon season and does
not have a dry hot summer as other regions in the state. The region experiences marginallylower temperatures than surrounding areas. Humidity in the region persists throughout theyear and rainfall is abundant3.
The climatic conditions of the state play an important role in the brick production acrossthe entire state of Assam. 6 months of the year there are more than an average of 15 daysof rainfall. Thus only around 6 months brick production is possible unlike the plains where
this extends upto 8 months. With an average of 5 lakh bricks per month, this amounts to a
maximum of around 30 lakhs bricks per year compared to around double the amount in the
Northern and Central part of India.
Figure 2: Climatic data for Assam state (WorldData, 2020)4

In addition to the rainfall, it is seen that the average humidity of the state of Assam is on anaverage around 80%. This has quite an effect on drying of the unfired bricks. Drying of bricks
is the process of removal of moisture within an unfired brick. Open air drying is an economic
choice to most of the brickmakers where climatic and atmospheric conditions are suitable.
Drying of unfired bricks is a process in which the water is eliminated from the bricks which
shrinks in the process. Accordingly, based on the type of soil used for making bricks the watercontent might vary upto even 40% of the total weight of the bricks. This has to be reduced
3
4

Status of Environment and Related Issues, Assam Science, Technology and Environment Council, Ministry ofEnvironment, Forests & Climate Change, Government of India, Available at: http://asmenvis.nic.in/Database/
Climate_1042.aspx
WorldData. (2020, January 1). Climate in Assam (India). Retrieved from WorldData.info: https://www.worlddata.
info/asia/india/climate-assam.php

Pre-Feasibility Studies for Implementation of Green Brick Production | 13

to below 0.5% for optimum firing. This is also directly proportional to time taken. However,in most of the cases the bricks are externally dry but contain an overall moisture of between
5-7% by weight. Under the conditions of humidity and temperature that exists in Assam it
cannot be dried further. There will always be a moisture content of around 5-10% within theunfired bricks.
It is generally calculated that around 3% of energy is required to remove 1% of moisture. Thismoisture is in the form of free moisture within an incompletely dried unfired brick. Therefore,
if the moisture content of a unfired brick is around 10%, then you would require around 30%of the total input energy to drive out this moisture. Removal of moisture is important during
the firing process since chemical reactions will not start until and unless the free moistureis removed. To remove free moisture, energy in the form of external fuel is needed. For any
type of clay brick firing process, it is directly related to the consumption of coal. Thus, if there
is a moisture of around 10% in the unfired bricks in Assam, then around 30% of extra coal iswasted to drive off this moisture. Given the climatic conditions of Assam and the moisture
content, total removal of moisture is not possible and thus wastage of coal is a given truth.
In the state of Assam, no scientific study has been undertaken to define the optimum
moisture content in unfired brick considering the geographical and soil quality conditions. A
study needs to be taken up to define the optimum drying time based on the soils of the three
topographical regions. This will immensely help the brick makers to decide on the drying
time and reduce their energy losses.

3.1.2 Demography
The total population of Assam is expected to grow from 31.17 million in 2011 to 34.18 million
by 2021 and 35.60 million by 2026. Within this rapidly rising population, the urban populationin the state stands at about 14.08% which is significantly lower than the national figure of
31.16%, however, decadal population growth in urban areas (27.89%) is higher than for rural
areas (15.47%) indicating a growing trend towards urbanisation.5
Women in rural areas make up more than 40% of the state’s population and the overall
female literacy rate in the state at 67.27% fares marginally higher than the national averageof 65.46%. Further demographic statistics are provided in the table below.
Table 3: Demographic Profile of Assam (Census 2011)
Demographic Indicators (2011)
Total population

31,169,272% contribution to national population

2.58

Population density (per sq. km)

397
Rural-Urban Composition

Rural

85.92

Urban

14.08

Decadal growth rate - Rural (in %)15.47

Decadal growth - Urban (in %)27.89

Female population - Urban

21,38,088

Female population - Rural

131,28,045

Male population - Urban

22,60,454

Male population - Rural

136,78,989
Population Facts

5

Scheduled castes population

7.15%

Scheduled tribes population

12.45%

Census (2011), Primary Census Abstracts, Registrar General of India, Ministry of Home Affairs, Government ofIndia, Available at: http://www.censusindia.gov

14 | Pre-Feasibility Studies for Implementation of Green Brick Production

Literacy Status
Literacy rate (%)

73.18

Male literacy rate (%)

78.81

Female literacy rate (%)

67.27

This decadal growth in urban population is quite important considering the fact that it willlead to rapid urbanisation. This will directly have a consequence on the demand of bricks
since housing and infrastructure demand will go up. However, it is predicted that this growth
will be more in the capital city and Tier II and Tier III cities and towns. To cater to this demand,
more clay brick making units will come up until and unless alternative walling materials aredeveloped and practised.

3.1.3 Economic Profile
Between 2017-18 and 2019-2020, the Gross State Domestic Product (GSDP) grew at an
average annual growth rate of 7.18% to reach a total of INR 2,59,997 crores at current prices
in 2019-20. The estimated annual per capita income in Assam in 2019-20 stood at INR 72,289
which is lower compared to the national figure of INR 1,11,782 (DESA, 2021).
Sectorally, the highest average annual growth was seen in the industry sector at 10.58%
followed by the service sector (6.87%) and agriculture & allied sector (2.35%). However,the contribution of industry, comprising manufacturing, construction, electricity and watersupply, is only 13.68% of the GSDP, which is less than the national figure. About 52% of theworkforce of Assam is currently engaged in the agriculture sector, which contributed 24.44
percent of GDP, more than India’s average. The sectoral distribution within the GSDP of thestate has been shown in Figure 3 below.
Figure 3: Economic profile of Assam

Source : Directorate of Economics and Statistics, Government of Assam

The contribution of the construction sector to the GSDP is around 10%. Thus it is quite
an important industry in Assam. However, in the construction most of the contribution isfrom the cement, sand and the steel industry. If the brick industry is regulated, then it isexpected that this contribution will grow even further. The related sectors of manufacturing,utility services, repairs, tourism, and real estate contribute a cumulative of 36% to the GSDP.
Growth in all these sectors will also indirectly boost the construction sector accelerating thedemand of bricks and therefore the brick sector.

Pre-Feasibility Studies for Implementation of Green Brick Production | 15

3.1.4 Geology of North East India
The Himalaya is the largest orogenic belt of the world, where a continental crust thrusts
another continental crust. The entire Himalayan arc evolved as a consequence of thecollision of the Asian and Indian continents about 50 million years ago.
In Northeast India and its adjacent regions, convergence occurs between three major plates- India, Eurasia and Sunda. The domain between 20°N—31°N in latitude and 86°E—98°E inlongitude (Fig. 4) thus includes two major mountain ranges, the Eastern Himalayas to thenorth and the Indo-Burma Ranges to the southeast, in addition to a large intraplate domain
of India.
Northeast India is a region of tectonic complexity and diversity that mainly stems from its
evolutionary history and subsequent modifications to its structure imposed by an on-goingcollision in the North and the Indo-Burmese convergence to the East. This is indeed testified
by the surface geology and sustained seismicity.
The region comprises distinct geological units, i.e., the Himalayan frontal arc, the highly
folded Indo-Burman mountain ranges, the Brahmaputra alluvium in the Assam valley, theShillong plateau and the Mikir hills (Figure 4). The Shillong plateau, believed to be upliftingeven at present, is the site of the 1897 Great Assam earthquake of M &gt; 8.0. The Assam valley
is a narrow E-W trending feature, filled up by sediments brought by the Brahmaputra river
system. The prominent geological units of the northeast India region remain geophysicallyless studied owing to the inaccessibility of this terrain.
Figure 4: Tectonic mapping of North East

16 | Pre-Feasibility Studies for Implementation of Green Brick Production

Understanding the geo-tectonics activity is essential to have an idea on the rock formationand therefore the derivatives of it e.g., brick and kaolinitic clays.

3.1.5 Geology of Assam and availability of resources
The State of Assam, a fertile land known for the famous Brahmaputra Valley hosts most of
the natural drainage and transport network of north-east India. Three major physiographic
divisions are the Brahmaputra plain extending eastward for 720 km from Dhubri, the Karbi
Anglong-North Cachar Hills block of metamorphic and sedimentary rocks and the Cachar
plain in the south, comprising Hailakandi, Karimganj and Cachar districts.
Precambrian gneisses, schists and quartzites surrounded by the vast recent alluvium areexposed as isolated hillocks in the Brahmaputra Valley (Figure 5). The hills of Karbi Anglong
are composed of gneisses and schists with granite intrusions. Folded Tertiary sedimentariesof the Naga-Arakan sequence comprise the North Cachar Hills, while the Cachar plains form
part of the Barak-Surma river system, are composed of alluvium covered young Tertiary
sediments. Frequent floods along the Brahmaputra river is a major recurring natural hazard
affecting the State, while the Cachar plains and North Cachar Hills areas are prone to frequent
earthquakes of moderate intensity.
Figure 5: Geological and Mineral map of Assam

Source : Modified from Geological Survey of India and Environmental Earth Science

Crude oil is found in the upper part of the Tertiary Barail sequence, where the largest amountof oil has been discovered in this region so far, while Tipam sandstone is another important
oil-producing horizon. In the shelf zone, oil was discovered just above the basement at
Borholla and gas in Eocene sand near Tengakhat coalfields.

Pre-Feasibility Studies for Implementation of Green Brick Production | 17

The Tertiary coal deposits of Ledo, Makum, Dilli –Jeypore and Mikir Hills area are the majorcoal resources of the State. The coal deposits in Mikir Hills occur within Sylhet Formation.
The coal occurrences in Assam are reported from two geological horizons viz., Gondwana
and Tertiary, of which Tertiary coal deposits from Makum, Mikir Hills and Dilli-Jeypore are
the most important of Jaintia Group and are located in the southern part of Mikir Hills and to
the north of the railway line between Lumding and Dimapur. However, most of the coal has
high sulphur content.
Three prominent limestone bands Shella Formation occur between Jadukata River inthe west and Lubha River in the east, where inferred reserves of limestone are about 900
million tonnes are estimated in Upper Sylhet Limestone (6.5 km length X 2.5 km width) near
Lobang, Longkingdong, Larphing and Baralarphing, while at Timbung area 4.6 million tonne
reserve of cement grade limestone is established, while 105.6 million tonnes of limestone
is known around Langkri nala on Garampani-Lauka road in North Cachar Hills. Preliminary
investigation revealed inferred reserve of 12.35 million tonnes of cement grade limestone at
Boralokhinder in North Cachar Hills, while a band of ferruginous limestone (15-60 m thick)occur near Selvetta-Meyongdisa area over an area of 5 sq. km along the Jamuna valley. 31
million tonnes of cement grade limestone occur near Koilajon-Dilai area in Mikir Hills over an
area of 12 sq km. The total inferred reserve of limestone from Mikir Hills is about 154 million
tonnes.
Minor base metal sulphide minerals are reported from Gneissic Complex of Mahamaya
Pancharatna and Agia areas and Deolina and Khardong Hills in Goalpara district. In Karbi
Hills, occurrences of sulphide minerals (pyrite and chalcopyrite) have been noticed in basic
rocks (epidiorite and amphibolite) and also in quartz veins traversing basic rocks around
Borjuri. Occasional sulphide minerals have been reported from suspected ultrabasic
diatreme in Luhajuri–Bajajuri–Tarapung areas.
Minor placer gold is reported from a few places in rivers of Upper Assam, of which Subansiri
riverbed yielded placer gold in the past. Minor occurrences of beryl are reported frompegmatite veins in Goalpara district and gneissic rocks in Naga-Largo-Mukjap area of thenortheastern parts of Karbi Hills. Carbonatite samples of the Samchampi Alkaline Ultramafic
Carbonatite Complex yielded 1000 ppm – 1500 ppm Nb and high concentration of Zr and Sr.
Indications of radioactivity to the extent of 3 to 4 times background value on G.M. counter
have been noted on a quartz vein body located SW of Pancharatna and laterites of Dillai areain Karbi Anglong district in Kailajan River.
Iron ore associated with ferruginous quartzite magnetite, hematite and goethite are foundnear Chandradinga Hill, Chakrasila range and Malai Hills in Goalpara district. The estimatedreserves are 12 million tonnes in Chadradinga Hill, 2.2 million tonnes in Malai Hill, and0.64 million tonnes in Chakrasila range. A reserve of 7 million tonnes and 1 million tonnes
in Lengupara and Kumri Hills respectively. A few bands of banded hematite–quartzite
are located near Ranighat for an extent of about 1500 m. Iron ore occurrences have beenreported from Malegarh and adjacent Lengupara and Kummi hills in the Goalpara district.
Granite and granite gneisses occurring in Goalpara, Kamrup and Nagaon districts arequarried for use as building and road metals, while pink and grey granite found in parts of
Karbi Hills and Goalpara and Dhubri districts and Agiyathuri and Digheswari hill ranges (near
Guwahati) are suitable as dimensional stones.
In Upper Assam, hard and massive sandstone underlying the coal measures are foundabundantly in headwaters of the Namdang, Ledo and the Likha streams, the Tipang andTirap Rivers. Laterite, ferruginous conglomerate, compact hard calcareous sandstone andferruginous of the Surma Group in Cachar district are also used locally for building purpose
and road metals. Fire clay commonly occurs in association with coal seams of Upper Assam.

18 | Pre-Feasibility Studies for Implementation of Green Brick Production

Several thin fire clay bands containing small amounts of impurities are found with seams
in Makum and Jaipur coalfields. A three to five metre band of fire clay occurs below coaloutcrops at Koilajan in Mikir Hills. Inferred reserve of this deposit is about 2 million tonnes.
Another 1.5 m thick band of white clay is found associated with coal seams at Selvetta area
containing an inferred reserve of about 55,000 tonnes. In Namdang-Ledo area, fireclay
bands are found below the coal seams that belong to the Barail Group. The inferred reserveof fireclay around Namdang is estimated to be 47,115 tonnes. Kaolin is reported from DoraRiver in Lakhimpur district.
Recently, kaolin has been found as an altered product of feldspar in granites of Selvetta area.
An occurrence of inferior quality fuller’s earth has been reported from north of Bhutan Khuti,
north of Suban Khata on the left bank of Pagladiya River in northern part of Kamrup district.
The inferred reserve is 13 million tons. Large deposits of black alluvial clay (Oil well drillingclay) are located near Mathurapur along Sibsagar–Nahorkatiya road in Sibsagar district.
Black clay is also found within Dihing Group and Older Alluvium in several parts of Dibrugarh
district.

3.1.6 Availability of clays for bricks
From the brick making and construction perspective, soils of Assam can be broadly divided
into three divisions’ i.e. alluvial soils, lateritic soils and fluvial soils. The alluvial soils areformed by weathering of rocks by flowing rivers. Thus, in and around the floodplains of theBrahmaputra and its various tributaries and distributaries, alluvial soils are found. These are
generally finer grained in the downstream areas of rivers but are suitable for brick making.
These are silty clay in nature but low in plasticity. These are good for clay brick making andabundantly available in Assam.
Figure 6: Soil map of Assam showing the available soils suitable for brick making

Source : National Atlas and Thematic Mapping Organisation Eastern India

The most preferred soils are the older Terai soils found in the Sivalik ranges along the foothillsof the Himalayas. These soils are generally rich in organic matter and are extremely suitablefor good quality clay brick making. In fact the organic matter content in the soils provides
energy from within the bricks thus reducing the need for external energy.

Pre-Feasibility Studies for Implementation of Green Brick Production | 19

In some parts of Assam there are occurrences of Bhabar soils. These are coarse grained soils
generally found parallel to the mountains and are formed by deposition of coarse grainedsoils by rivers. Although these soils are not suitable for clay brick making but due to its clean
nature, they can be very suitable for making concrete products. Generally, Bhabar soils arecoarse-grained, roundish in shape and need to be crushed for use in concrete products.
The Karbi Anglong, Diphu and Cachar hills are typically characterised by sandy to loamy
iron-rich soils. These soils are formed under conditions of high temperature and heavy
rainfall with alternate wet and dry periods, which leads to leaching of soil, leaving behindoxides of iron and aluminium. Since these soils are sandy in nature and lack plasticity, they
are not suitable for making good quality clay bricks. In isolated areas, lateritic soils are being
used for brick making in clamps. However they are not of very good quality and often resultin high breakage. Contrary to their use in clay brick making, these lateritic, sandy and loamy
soils can be very useful raw materials for producing compressed earth blocks.
The figure given below shows the approximate zoning of building material production in
Assam. This is a suggestive map and can be used for zoning of building material production.
Figure 7: Zoning of Building Material Production

Source : Modified from National Atlas and Thematic Mapping Organisation Eastern India

The above zoning of the prevalent soil types of Assam informs us on the location andavailability of raw materials (soil, sand) for production of any proposed brick or masonrymaterial. It can be observed that the soil for making compressed earth blocks is the lateritic
and loamy soil, prevalent in southern parts consisting of Karbi Anglong Diphu and Cachar
hills. Bhabar soil, which is suitable for making concrete products, is naturally available in
the Northern areas of Lakhimpur and Udalguri districts. Alluvial soils, predominant in the
Terai region are found abundantly along the floodplains of the river Brahmaputra. These aresuited for the soil mix of burnt clay bricks. By locating these regions through GIS mapping
data, a correlation can be made with the ground situation of brick production units in Assam.

3.1.7 Availability of alternate resources
Apart from clay, one of the major raw materials used in burnt clay brick making is coal. With
the emphasis of Government of India and International agencies on reducing use of fossil
fuels to reduce CO2 emissions, the study also explored local sources of renewable fuels.

20 | Pre-Feasibility Studies for Implementation of Green Brick Production

The map below (Figure 11) shows the approximate distribution of agriculture in Assam.
Some of the major crops being cultivated are rice, wheat, sugarcane, maize, tea etc. Thesecrops produce substantial amounts of agricultural wastes in the form of stalks, stems, husksetc. These, if compressed in the form of green briquettes, can be an excellent renewable fuelfor use in clay brick making. Incidentally these are also aligned to the brick production areas
making it profitable and manageable to use.
Figure 8: Availability of agriculture produce and biomass in Assam

Source : mapsofindia.com

3.2 Overview of brick production in AssamAs per the detailed documentation and analysis conducted by the project team through fieldvisits to the identified demand centres, this section presents the research findings regarding
brick production capacities and associated processes and impacts in the state.

3.2.1 Quantification of brick kilns in Assam
There have been quite a number of issues in identifying the number of brick kilns in thestate of Assam. As per published figures from PCBA till December 2012, there were 731 brickkilns across the State. 193 out of these 731 brick kilns were operating illegally and flouting
environmental regulations under the Air (Pollution Control and Prevention) Act, 1981.
However, no reliable secondary data could be found to validate these numbers. Recently it
was also reported by the State Environment and Forest minister Parimal Suklabaidya on 5th
March 2020 that there are 669 brick manufacturing kilns operating in Assam as per reports
collected from the Divisional Forest Offices. This was in reply to questions during the Budget
Session of Assam Legislative Assembly on 5th of March 2020. It was also stated that the Assamgovernment’s revenue collection from brick kilns as per Assam Mineral Concession Rule,2013 has drastically dropped from Rs 3.07 crore in 2018-19 to Rs 1.32 crore in 2019-20 (up to
January), excluding Sixth Schedule areas. It was also mentioned that the quantum of earth
used by brick kilns in 2019-20 (till January) is 362,928 m³, which is also half of the previous
year figures which were 655,906 m³.

Pre-Feasibility Studies for Implementation of Green Brick Production | 21

As per the reports received from the PCBA, the status of brick kilns in Assam based on districts
is as follows:
Table 4 : List of brick kilns as received from PCBA
Division

Barak Valley

Central Assam

Lower Assam

North Assam

Upper Assam

Divisional Head
Quarters
Silchar

NagaonGuwahati

TezpurJorhatDistricts

No. of brick kilns

Cachar36

Hailakandi

20

Karimganj

24

Dima Hasao

NA

Hojai

11

East Karbi Anglong

NA

West Karbi Anglong

8

Morigaon

76

Nagaon

77

Baksa

23

Barpeta42

Bongaigaon

47

ChirangNA

Dhubri

147

Goalpara

15

Nalbari

14

Kamrup Metropolitan

53

Kamrup Rural

76

Kokrajhar

10South Salmara-Mankachar

NA

Biswanath

57

Darrang

66

Sonitpur

107

Udalguri11

Charaideo

19

DhemajiNA

Dibrugarh

90

Golaghat

33

Jorhat55

Lakhimpur

6

Majuli7

Sivasagar

45

Tinsukia

67

Total

1242

22 | Pre-Feasibility Studies for Implementation of Green Brick ProductionSince the focus areas of interventions were Silchar, Dibrugarh and Guwahati, a more detailed
survey was conducted through GIS mapping for these geographies. The results of the same
are presented in the Table 5 below.
Table 5: Details of kilns surveyed
Demand Centre

No. of kilns
Interviews conducted

No. of kilns
GIS mapping

No. of kilns
As per PCBA data

Guwahati

23

112

129
(metro and rural)

Silchar32

83

80(all 3 districts)

Dibrugarh

14

51

90

Maps showing all surveyed kilns in the three regions are presented below. Although the datafrom the GIS mapping exercise does not accurately overlap with data from PCBA, it allows fora fair estimation of the present conditions.
To arrive at an accurate record of all the brick kilns in Assam, the following is recommended:•

Partnering with UNDP for mapping existing brick kilns using the Geo AI tool and verifying
the same through ground truthing surveys•

Henceforth, all NOC (No objection certificate) applications of brick kilns shall bemandated to provide GPS data of the respective brick kiln. This shall provide a databaseof the number of brick kilns and their precise location, for efficient monitoring andregulation by PCBA and other authorities

Pre-Feasibility Studies for Implementation of Green Brick Production | 23

Figure 9: Map of brick kilns in Guwahati (Source: Author)

Figure 10: Map of brick kilns in Silchar

Figure 11: Map of brick kilns in Dibrugarh

Source: Google earth

24 | Pre-Feasibility Studies for Implementation of Green Brick Production

3.2.2 Soil quality
To understand the soil quality in the three priority areas of Guwahati, Silchar and Dibrugarh
and its relation to brick making, the soils of the three regions were tested. A total of 7 soil
samples were collected and tested for sieve analysis and XRD for phase analysis. The sieve
analysis is given in Table 5. The X-ray diffraction analysis of the soils are also given in Figure 12.
Table 6 : Sieve analysis of brick making soils in priority areas
Sieve analysis

Guwahati

DibrugarhSilchar

>1.18

2.38%

2.91%

1.54%

1.18 - 600

1.16%

3.11%

1.28%

600 - 150

7.53%

30.29%

19.14%

150 - 75

29.06%

20.01%

33.10%<75µm

59.28%

43.00%

44.51%

Figure 12: X-ray diffraction analysis of soils from Guwahati, Silchar and Dibrugarh

In the priority areas of the study no other soil types were found. This is mainly due to the flood
plains topography of the areas. Dibrugarh and Guwahati are dominated by the Brahmaputra
flood plains and Silchar by the meandering flood plains of Barak river. Thus there is scant
scope of alternate building materials for brick making in these priority areas.
The results of sieve analysis are in agreement with the flow pattern and sedimentation of therivers. The soils of Dibrugarh are coarser compared to Guwahati. This is due to the reason
that the Brahmaputra flows for a distance of around 400 km from Dibrugarh and enters
Guwahati. The soils get finer due to the flow of water and required fineness from attrition ofparticles. This is proven by the fact that Guwahati soils are finer than Dibrugarh. For Silchar
the soils are even finer in nature. This is mainly due to the fact that the Barak river originatesin Manipur and flows a distance of more than 200 km before it flows through Silchar. The
characteristic meandering of the river makes the soil much finer as compared to other soilsof the region.
The XRD analysis (Figure 12) of the soils show a predominant phase of quartz. The clay
content is much less with minor presence of muscovite and other micaceous minerals. Not
much difference is seen in the composition of all the 7 soil samples collected.
Looking at the possibility of use of soils from the river banks and floodplains it is suggested
that an extensive study be taken up to characterise such type of soils across various river
basins and tributaries of major rivers e.g. Brahmaputra, Barak, Dhanasiri, Manas etc. If soils
can be sustainably and scientifically excavated from the river beds then it will prevent use of

Pre-Feasibility Studies for Implementation of Green Brick Production | 25

agricultural land for brick making. Moreover, it will also help in dredging the rivers, thereby
improving water flow and reducing flooding during monsoon seasons.

3.2.3 Brick production trends
The variations in brick kilns in Assam with respect to scale and size were evident from thedata collected on brick production capacity of individual kilns. Annual production in kilns
ranged from anywhere between 7 lakhs to 40 lakhs in FCBTKs and going up to 63 lakhs inzigzag kilns. The average chimney size as observed during field visits for FCBTK was 90-100
feet and 110-120 feet for Zigzag kilns. Brick production capacities and methods did not varymuch across the three regions.
The team visited and collected information from several kiln clusters in Guwahati, Silchar
and Dibrugarh. All kilns could not be covered exhaustively due to field challenges suchas inaccessibility of kilns, hostile environments along with security concerns. Based on
the visited clusters, the geographical coordinates of kilns were mapped for several kilns.
In addition to the kilns surveyed physically, further kilns were identified through visual
mapping using Google Earth. This mapping was based on recognition of the brick kilns
based on distinctive characteristics visible in the satellite data including shape of the kilns,
height and size of the chimney, area of the soil that is being excavated from surroundings,
visible through colour variations.
Figure 13: Different kilns from the demand centres. Semi-covered kiln design suchas the one observed in Silchar (centre) allows for brick production during adverse
weather conditions(Source: Author)

For Guwahati region, the average brick production rate of Fixed Chimney Bull’s Trench Kiln
(FCBTK) was about 22 lakh/year, whereas in Zigzag kilns the rate of production was almost
double that of FCBTK at 40 lakh/year. In Silchar, 32 brick kilns were observed. Out of these,
the average brick production rate of FCBTK was 21 lakh/year and that of Zigzag kilns was 45
lakh/year. In the Dibrugarh region, 14 brick kilns were observed. Out of these, the averagerate of brick production from FCBTK was 19 lakh/year and that from Zigzag kilns was 36 lakh/year.

26 | Pre-Feasibility Studies for Implementation of Green Brick Production

Table 7: Average annual brick production in demand centres
S.no

RegionType of kiln

Average annual brick production (in lakh)1

Guwahati

FCBTK

22.04

Zig-Zag

40.33

FCBTK

21.70

Zig-Zag

45.00

FCBTK

19.5

Zig-Zag

36.00

2
3

Silchar

4
5

Dibrugarh

6

Firing rounds
Firing rounds are typically described as the number of bricks fired for one complete round of
the kiln. As per the data analysis, the number of firing rounds per year mostly ranged from 3
to 5 per year across the different regions of Assam i.e. Guwahati, Silchar and Dibrugarh. The
number of rounds conducted each year depends on factors such as availability of labour,
availability of coal, rainfall pattern, mining regulations with respect to coal and soil.

Brick Parameters
Samples of bricks were collected from various kilns and tested for basic parameters including
dimensions, water absorption, and compressive strength. Apart from red bricks, few samplesof Aerated Autoclaved Concrete (AAC) blocks and fly ash bricks were also collected for testing
purposes and to compare red bricks, fly ash bricks and AAC blocks with respect to strengthand other parameters since they are also being used in construction.
The Autoclaved Aerated Concrete (AAC) block is a product of fly ash, sand and other raw
materials. These are mixed with lime, cement, water and an aerating agent. They aresolidified into required shapes through autoclaving. The AAC is mainly produced as cuboid
blocks. The AAC blocks are energy efficient, durable, less dense, and lightweight.
There were quite a number of issues with the moulding process and the resultant brickdimensions. Within the same kiln, dried unfired brick sizes ranged between 250-230mm x
115-110mm x 62-65mm. This will result in non-uniform and non-standard bricks This usually
happens if the mould sizes are not proper, too much water has been used during moulding,unevenness of the stacking area.
Thus proper training is required to entrepreneurs and moulders for making uniform andgood quality unfired bricks. This is most important and urgent since FCBTK is a firing process
only. Poor quality and non-uniform unfired bricks will result in similar quality of burnt bricks
only. Table 8 gives a summary of the quality of various types of bricks collected from thepriority areas. No AAC or fly ash blocks were available in Dibrugarh.
Table 8: Brick parameters as per lab test results
Size (length x breadth x
height) in mm

Type of brick(s)/
block

Water
absorption (%)

Compressive
strength (N/mm2)

Guwahati
235 x 110 x 70

Red

14.39

12.42

230 x 110 x 72

Fly ash

6.76

12.00

16.61

12.21

30.81

2.79

14.21

12.00

Silchar
231 x 114 x 68

Red

600 x 190 x 73

AAC
Dibrugarh

230 x 106 x 68

Red

Pre-Feasibility Studies for Implementation of Green Brick Production | 27

All the bricks from various areas were collected and tested in NABL certified labs in respective
cities. Details of the test reports are given in the Annexures. As per IS 1077:1992 the minimum
strength of any brick should be greater than 3.5 N/mm2. The water absorption should not begreater than 15%. Thus as per BIS both the burnt clay and the fly ash bricks are well above
the required standards. In addition, PWD and CPWD specify a requirement of 7.5N/mm2 forany construction using burnt clay or fly ash bricks. Even by PWD or CPWD standards thebricks of Assam are well above the permissible limit. However, the AAC blocks are poor in
quality and well below any standard. They should not be allowed in any construction except
external boundary walls. This should be checked immediately to avoid any catastrophic
failure of buildings.

Uses of fired bricks in the construction sector
After firing, bricks are majorly classified into three categories i.e. 1st class, 2nd class, and 3rdclass based on the size, colour, strength, and metallic ringing sound achieved as markers
of quality. The application of bricks in the construction sector varies as per the typology
and durability of the bricks. For example, 1st class bricks are majorly used for masonry andstructural purposes in the construction of buildings, whereas 2nd class bricks are used forconstruction of semi-pucca houses and 3rd class bricks are used for flooring and under filling
purposes.
Other bricks like AAC blocks are mainly being used as filler walls in multi-storeyed buildings in
the major cities of Assam. Fly ash blocks have not yet gained popularity for use in residentialbuildings. However, in certain cases it is used in high rise buildings and as boundary walls.

3.2.4 Existing Technologies and Processes
The usual raw materials for brick making are soil, anti-shrinkage material, internal fuel,and water. The common procedure used in brick manufacturing kilns in Assam has been
explained in detail as per the following steps:
Figure 14: Steps of brick-making process.

Excavation of soil

Preparation of
the soil

Soil mixing

Moulding of Bricks

Stacking of bricks

Firing of bricks

Transportationof bricks

Drying of bricks

Source: Author

Excavation of soil
Any brick production unit needs to have good quality soil to produce a high strength unfired
brick. Better the unfired bricks quality, better the fired bricks. Certain types of soil are notsuitable for brick making. For example, soil with a high sand content has no plasticity andis difficult to form into quality unfired bricks. After moulding such bricks have a tendency todeform and are prone to cracking during handling. Similarly, the soil used in pottery is notsuitable for manufacturing bricks due to its high shrinkage rate which causes the brick to
crack during drying. The availability of suitable soils has been discussed in previous sections.
Currently, brick owners are excavating soil from various sources in surrounding areas such as
barren land, river banks and mainly from agricultural land. The soil is excavated to a depth ofaround 3 feet to 9 feet, depending upon the quality and availability of soil, using mechanicalexcavators or earth movers. The land which is dug at a depth of 8-9 feet is sometimes used

28 | Pre-Feasibility Studies for Implementation of Green Brick Production

as a pond by the people for fishing purposes. But if found unsuitable for pond usage, it isleft barren. On the other hand, the land from where the soil is excavated to a depth of 3 feet
continues to lie barren or is sometimes used for agriculture if found suitable. All brick kilns
based in Guwahati, Silchar and Dibrugarh, were employing the same process of excavating
the soil mechanically using excavators or earth moving machinery.
Figure 15: Excavation of soil using earth movers

Figure 16: Deep excavation of soil leaves behind barren land (bottom).

Source: Author

Preparation of the soil
Once the process of soil excavation has been completed, it is then spread evenly on the
ground at a height of around 1 feet. The soil is further cleaned by removing stone particles
and then the water is sprinkled over the soil which is left for 24 hours for proper ageing. This
process is done manually by hand.
In and around the three brick making locations visited e.g. Guwahati, Silchar and Dibrugarh,
the soil is usually delivered by small and big trucks. At a few places it was observed thatsoil is mined directly in the brick making locations at present. Whereas in a few kilns it
was observed that brick entrepreneurs have stored the soil in large heaps. Stacking of soil
helps in proper ageing of the soil and it also helps in the quicker production right after the
Pre-Feasibility Studies for Implementation of Green Brick Production | 29

monsoon season is over rather than procuring it from outside. It was observed that most of
the kilns in Assam have stacked the soil in the form of small mounds up to a height of about
3-5 feet for later usage. Generally, the soil which is stored in a season generally lasts for about
4-5 months. After stocks are depleted, they are again replenished for present consumption
as well as the next season.
Moreover, stacking of soils in a predetermined manner helps in managing the processing of
the soils. As per need, and informed by practical experience, both plastic and non-plastic
soils are stacked in layers. This is to ensure that suitable soils are available for moulding.
During the season and before the start of moulding the two types of soils are mixed together
by mechanised and semi-mechanised means.

Soil mixing
An essential part of any brick making activity is the process of mixing the raw materials into asmooth uniform mass. This is necessary because a good and uniform unfired brick is the key
requirement for a high quality product. Two types of soil mixture processing were observedin different regions of Assam. However, the most commonly and widely followed mixing isthrough pug mills.
(i) Mixing through semi-mechanized process (The pug mill)
Figure 17: Semi-mechanised equipment such as pug mills can be seen being used atkilns for mixing soil.

(Source: Author)

In this process of wet mixing, the mixed soil is cut manually from stored heaps. In the process
preliminary mixing is ensured. They are then opened out in layers and watered. The measureof water is by experience. The watered soil is left to age for at least 8-12 hours. Next day
the aged soil is cut in layers from top to bottom and loaded in small hand carts known as
wheelbarrows for transportation to pug mills (mechanised mixing machines). The pug mills
are generally placed near the soil heaps to minimise transportation. These pug mills are
installed within the ground with 2-3 workers engaged in taking out the pugged soils which
are then carried to respective moulding sites by moulders. This type of mixing is followed
in almost all the open firing techniques e.g., Fixed Chimney Bull’s Trench Kiln (FCBTK) andZigzag kilns.

30 | Pre-Feasibility Studies for Implementation of Green Brick Production

(ii) Mixing through mechanised process (tractor operated pugmill)
Figure 18: Mixing of soil using tractor operated pugmill.

(Source: Author)

Tractor operated pug mill was also being used in a few places for soil mixing. In this method,
the pug mill is attached to a tractor, in the centre of the conical shaped pug mill, there isan iron shaft. To this shaft are fixed a number of arms with several vertical cutting blades
attached to each arm. The central iron shaft is then rotated mechanically by the tractor which
is operated by using tractor, diesel or electric power.
Blended soil along with the required quantity of water is fed in the mill from top. When theshaft rotates the cutting blades, fitted to arms, cut through the clay and break up all clods
or lumps of clay. After the clay has been thoroughly pugged then it is taken out through an
opening provided in the side near the bottom.

Moulding of unfired bricks
Two types of unfired brick moulding processes were observed - manual moulding andmechanised moulding using extruder machines(i) Manual process, hand moulding
Figure 19: Brick moulding by hand in process.

(Source: Author)

Pre-Feasibility Studies for Implementation of Green Brick Production | 31

Figure 20: Design of mould for brickmaking.

The most common unfired brick making
process that was observed in Guwahati,
Silchar and Dibrugarh is through manual handmoulding. This method is adopted when alarge and level area of land is available for the
purpose. The area of land on which moulding
is to be done is levelled, plastered smooth andsprinkled over with sand.

Moulding is done at ground level thoughsitting and not in a standing posture. To
prevent the moulded bricks from sticking
to the moulds either sand is sprinkled on
the inner sides of the mould or the mould isdipped in water each time before moulding isdone. Sand moulded bricks have better finish
and sharper edges.In some kilns, moulding
was being done by female members while
in some cases the female member assists in
preparing the dough while the male member
does the moulding and vice-versa. In one day,1 person makes around 1000 bricks at a cost of
60 paise to INR 1 per brick depending upon thearea. To cast the bricks, two types of moulds
are being used i.e. wooden and plastic by themoulders. Moulding is done through a single,
open mould system and is of (a) 250mm x
Source: Author
120mm x 70mm, (b) 250mm x 130mm x 75mm
size. The mould size varies from place to place
depending on the shrinkage of the soil. For instance, at a few brick kilns, size of 235mm x
120mm x 65mm, 220mm x 105mm x 64mm and 224mm x 121mm x 73mm after firing wereobserved.
Another important observation was that in a few kilns, moulds were defective in nature
which impacts the quality of the bricks during the firing process resulting in broken edges
and corners instead of being sharp. At some brick kilns, it was also observed that the processof brick moulding is being done by using automatic unfired brick production machines. As
per the observation, once the bricks are dried, they are stacked in multiple rows having notmore than 5 to 6 bricks in a single row to avoid breakage of unfired bricks due to heavy load.
The entire process of soil homogenization, ageing, pug milling, moulding and stacking
is done through a single contractor or site supervisor. There are separate teams for soil
preparation, transportation to field to kiln, kiln to field, moulding activity etc.
The entire process of moulding is done in the open atmosphere under the sun. Moulding
is generally done as per the convenience in two shifts. In winter months, it’s done in themorning and afternoon. In summer months, moulding is usually done in the early morningand late afternoon.
Bricks moulded directly on the ground have their lower faces objectionably rough and canhave no frog. Frog is an indentation provided in the face of the brick. It may carry the trade
mark of the manufacturer such as Lucky, Nokia, LG bricks etc. as observed in the Assamregion. Bricks are laid in masonry with frog up. Frog provides a key for the mortar and holds
the bricks on top firmly in place. To avoid breakage, bricks are moulded on a block of wood
known as the moulding block, having a projection 0.5 cm thick and of same length and
32 | Pre-Feasibility Studies for Implementation of Green Brick Production

breadth as the inside of the mould (Fig. 2.4).In this case the mould should be made 0.5 cm
deeper than the thickness of brick. The mould is so placed on the moulding block that it
closely fits round the projection. The projected portion is protected by means of metallic
strips. To provide frog or any other impression on the finished brick a corresponding raised
projection is provided on the projection itself as is clear from the figure. The clay is then filledin the mould as explained before and the brick is moulded. Then a thin fiat board a little
larger than the mould, known as the pallet, is placed on the mould containing the brick.
The moulder then lifts the mould containing the brick and sandwiched between the pallet
and the moulding board, inverts it bringing the pallet below. He/she then removes themoulding board and the mould, leaving the brick on the pallet. Another pallet is then placedon the brick which is then carried between the two pallets to the drying site and laid on theside. The next moulded brick is placed by its side and the process repeated. As the bricks
in this method are not laid flat for drying, as in moulding directly on the ground, but on thesides so lesser space is required for drying in this method. The bricks dry better and quicker,
and also the faces are all smooth.
(ii) Extrusion process
Figure 21: Automatic movable brick extrusion machine

Source: Author

In Guwahati it was observed that at one or two kilns, unfired bricks were also being madeusing a fully mechanised machine which is known as automatic movable clay brickproduction machine. The truck, which is also the brick-machine, holds a generator, a mixer,
and a mould to produce bricks. Once raw materials are added into the truck, the bricks areready to be laid. A driver has to operate the machine and move it over the field, where thebricks are to be baked.
The mixture is supplied through a system and finally reaches the mould, which is placed
behind the wheels. From one foot off the ground, the mould gently drops the bricks andcontinues to do this with every inch the vehicle moves. Once the unfired bricks are fully
dried, the bricks are then ready to be transported from field to the kiln for firing.
However, the quality of unfired bricks that are being produced by using an extruder machine
is not of very high standards compared to that of hand moulded bricks. While the edges are
sharp, with smooth corners and glossy finish, the overall quality is impacted by the plasticityof the soil which is quite high in most of the areas of Assam. Due to these characteristics ofthe local soil, mechanised extruder machines have not seen much success in the region for
wider adoption.

Pre-Feasibility Studies for Implementation of Green Brick Production | 33

Figure 22: Mechanized extrusion process.

Source: Author

Drying of bricks
Drying of bricks is normally done in the open atmosphere for conventional FCBTK and Zigzag
kiln technologies. After initial moulding on the flat side, they are overturned on the longer
side after 24 hours of drying. In winter months, the drying duration is increased by about
25%. After leather hard conditions, they are stacked in rows.
Generally, the stacks are openly packed and in most cases are about 5-10 bricks high. Some
additional bricks are kept at the top layer also in case of emergencies. To protect the stacked
layers from damage due to water logging, each row of unfired bricks is generally kept on alayer of fired bricks. This is to ensure that the bottom most layers of unfired bricks are notdissolved leading to toppling of the whole stack. It was observed that in Assam mostly kilns
were following this practise of drying the bricks. In some kilns, it was also observed that thedried unfired brick stacks were covered in long plastic sheets to protect from the sudden
rains. In a few kilns, they were also being stored in a shaded area which is made up of GI
sheets in order to protect it from the direct rain.
Figure 23: Different stacking patterns during brick drying phase (left and right).

Source: Author

34 | Pre-Feasibility Studies for Implementation of Green Brick Production

One of the most important observations was the presence of drying shrinkage cracks in theunfired bricks at a few places. Majorly it’s because the plasticity of the soil is high and whenit’s mixed using a pug mill, both the plasticity and density of the bricks further increases.
Therefore, when the bricks are dried, the outer surface appearance apparently gives a dry
look with the interior still containing high moisture and when the moisture forces itself
out through the capillary action, it results in hair crack or thick crack. This phenomenon istermed as unfired brick shrinkage.
Absence of air flows and very high humidity within the stacking and drying area hinders
uniform and reasonable fast drying of the unfired bricks during the winter season. Although
not much of a difference is seen in between the humidity and temperature of the winter andsummer months. It has also been observed that the unfired bricks are never optimally dry as
claimed by the entrepreneurs.

Unfired brick transportation
The topography of the brick making areas in Guwahati, Silchar and Dibrugarh makes use of
simple means of unfired brick transportation system. Since the area is flat, hand pulled carts
and wheelbarrows are generally used. In some areas it was observed that the transportationof the bricks is also being done by using a cycle and manually by loading the bricks (around10) on the head. Generally male workers were transporting the unfired bricks using cycle
or wheelbarrows and female workers were carrying it on the head. Of the three systems,
wheelbarrow one is the most preferred system for unfired brick transportation from thedrying area to the kiln loading since they have direct access to the kiln loading area. Also it
reduces the time and manual effort as well as labour cost.
Figure 24: Unfired brick transportation methods - on cycles, wheelbarrows andmanual carriage.

Source: Author

Pre-Feasibility Studies for Implementation of Green Brick Production | 35

Firing of bricks
In Assam, in and around the areas visited, two types of brick kilns were observed i.e. Fixed
Chimney Bull’s Trench Kiln (FCBTK) and Zigzag kiln. As per the observations, the brickindustry in Assam predominantly consists of FCBTK. The designs of the kilns are remarkably
uniform and all the kilns are more or less identical. There are three size variations in terms of
capacity being termed as half section, one section and one and a half section. Generally, theheight of the chimneys observed was in the range of 110-120 feet and around 200-250 feetlong having a trench width of 28-31 feet and a height of 8 feet.
Figure 25: Brick stacking patterns during firing – FCBTK (left) and zigzag kiln (right).

Source: Author

Initiation of the brick industry has been through the transfer of design and fire technology
within the Indian counterparts itself. Afterwards growth has been through replication of one
kiln to another. Thus most of the kiln designs that were observed are identical with no or
little variation in design and operation.
The firing observed in FCBTK kilns follows the conventional pattern as in most of India.
Most of the kilns are constructed on the ground with ordinary red brick walls followed by
mud plastering. There is a considerable amount of heat loss in the kilns from the below
mentioned areas:•

Side walls of the kiln•

Bottom of the kiln•

Non-insulated fire holes

Coal feeding is done through bigger sized spoons and in a continuous pattern. An appreciable
amount of unburnt coal was also observed at the bottom of the kiln. These unburnt coaltend to accumulate between the bottom most layers thereby over firing the bricks. In a way
this is desired since the over burnt bricks are manually broken to be sold as aggregatesfor construction work. Thus in spite of using a high chimney for appreciable draught, therequired coal savings are not seen due to the firing systems being practised.
In the Zigzag kilns observed in Guwahati, Silchar and Dibrugarh, the kiln size was comparatively
small and denser as compared to that of FCBTK. In a Zigzag kiln, the air is forced throughducts whereas in FCBTK, it’s induced naturally. However due to forced draught through an
induced fan the firing process is much faster than a fixed chimney. Normally FCBTK takes
about 20-26 days for a cycle due to a natural induced air system whereas in Zigzag kiln, one
cycle takes around 18-21 days. Also, the Zigzag kilns are much denser in terms of patternwhereas, FCBTK are more of an open pattern.
The process of firing is carried out throughout the period of 24 x 7hrs and is done in several
shifts by the labourers. It also depends on the availability of the unfired bricks, coal and theweather conditions. It was observed that in a few kilns, after firing, the upper surface of the

36 | Pre-Feasibility Studies for Implementation of Green Brick Production

bricks was white in colour which is due to the exposure to sunlight and wind that results inthe capillary action and water is being drawn to the surface. When the water evaporates, itcauses the salts to be left behind. These salts are known as scum salts which are a sign ofgood bricks and come into the category of 1st class.
Figure 26:Brick firing in process.

Source: Author

Stacking of bricks
From the unloading area, bricks are manually sorted and unloaded. Fired bricks are normallystacked following the local tradition. Depending upon the quality of the fired bricks, stacking
is done in three categories. Bricks in the upper part of the trench are typically under fired
and are classified into 2nd class. The bricks at the middle part of the trench are the best
quality and are classified into Class 1. Bricks at the bottom of the trench are over fired and are
categorised as 3rd class bricks. The stacks are well maintained and each of them contains anequal number of fired bricks. This is an advantage from the loading and dispatching point ofview. All the bricks are stacked in different places and as sold as per the gradation. Normallyas per the feedback received in FCBTK the class 1 percentage ranges between 70-75% andthe rest are 2nd and 3rd class. In both the firing technologies, the stacking pattern is similar
and is segregated as per quality, especially the metallic sound and colour.
Figure 27: Stacking of fired bricks.

Source: Author

Pre-Feasibility Studies for Implementation of Green Brick Production | 37

3.2.5 Consumption of fuel and raw material
The most common fuel used in brick firing in Assam is coal. No other alternate materials e.g.
biomass, oil or gas is being used. This is probably due to the easy availability and low cost ofcoal available in and around Assam and neighbouring states. In addition to coal, wood andeven rubber tyres have been seen used in firing. These are used only during the initial firing
cycle. Due to quite a long period of hiatus and the rainy season, all types of kilns have highmoisture in the ground and also in the outer and inner walls. To effect a faster drying of the
moisture and reduction on coal quantity, additional heat is supplied in the form of woodand other flammable materials only at the periphery of the firing zones. These do not haveany effect on energy required for brick firing. It was understood from the survey that on anaverage 18-20 tons of wood is used for brick firing in FCBTK’s. Wood and rubber tyres aremostly used to initiate the firing process while coal consumption continues on a round by
round basis.

Types of fuel used for firing and its mapping
Coal suitable for brick firing is generally found in the states of Assam, Meghalaya andNagaland. The coal of Meghalaya is immature sub-bituminous coal with high sulphur
content. However customers and brick entrepreneurs prefer Meghalaya coal due to its highcalorific value. Compared to Meghalaya, the state of Assam also has high reserves of coalmainly in the Upper Assam area in and around Tinsukia. This is also a bituminous coal withhigh sulphur content. In Nagaland the coal quality is sub-bituminous to bituminous-D in
rank, characterised by low to medium moisture (4%–7%), moderately high volatile matter
content (22% and 42%) and high sulphur (5%–11%) content. There are specific places
where coal is supplied to brick kilns. In and around Lower Assam of Guwahati-BongaigaonBilasipara-Dhubri region coal is sourced from Meghalaya mainly from Salang. For Silchar
since both Meghalaya and Nagaland are of similar distance, thus the coal procurement ismainly governed by economics. Various brick kilns procure coal from both these states. In
Dibrugarh which is located at a distance of 150 km from Nagaland, coal is usually procured
from various locations of Nagaland such as Naganimora and Margherita in Assam(Tinsukhia).
Figure 28: Types of fuel used for the firing of the bricks and it’s mapping

Source : Modified from www.freeworldmaps.net

38 | Pre-Feasibility Studies for Implementation of Green Brick Production

However, in all cases, the area to procure the coal is not fixed and depends mainly on thecoal availability in the market, its price and quality. Figure 28 shows the occurrences andprocurement map of coal for brick kilns in Assam.
However it was seen that coal is not procured directly from mines. In India coal is mainly
procured through e-auction. However the brick kiln owners are low consumers of coal andthus cannot procure directly from mines. In almost all the cases coal is procured from dealers.
Thus there is a flexibility of procurement based on price and quality. It was also noted thatcoal from Nagaland and Meghalaya is also procured in an illegal manner. There are no bills
or invoices based on which payments are made. This is quite a thriving business and quite alarge number of such suppliers exist in the two states. Since there are no regulations of coalusage and mining, thus during certain seasons shortage of coal is rampant resulting in black
marketing of coal and rise in prices.

Coal consumption
The consumption of coal has been calculated based on the two prevalent technologies i.e.
FCBTK and Zig Zag kiln. Table 9 shows the average amount of coal consumed in the threestudy areas.
Figure 29: Coal crusher machine in Silchar

Source: Author

The average coal consumption matches with the figures from other similar brick kilns in
the Indo Gangetic plains. However, the variation of coal consumption among the three
regions is also within assumption limits. The most important observation is the similarcoal consumption in Zigzag kilns. As per industry standards, there should be at least 2030% of energy reduction in Zigzag kilns compared to FCBTK. Since this was not seen, thus
it is inferred that the Zig Zag technology and process is not properly being followed. Thismight be due to lack of knowledge and improper technology deployment or adoption.
Thus training programmes and manuals are proposed to be made available for all alternate
technologies so that they can be followed.

Pre-Feasibility Studies for Implementation of Green Brick Production | 39

Table 9 : Region-wise distribution of average annual consumption

RegionType of Kiln

Average coal consumption (intonnes) per lakh of fired bricks

FCBTK

17.17

Zig-Zag

16.00

FCBTK

20.41

Zig-Zag

18.00

FCBTK

18.67

Zig-Zag

15.27

Guwahati
SilcharDibrugarh

It can be seen that the average coal consumption for making one lakh of bricks throughFCBTK was slightly higher in the Silchar region as compared to that of Guwahati and
Dibrugarh, whereas the coal consumption in Zigzag kilns was fairly in the same range
for Guwahati and Silchar but it was significantly lower in Dibrugarh. The variation in coalconsumption can be attributed to various reasons such as the quality of the raw material
available, plasticity and moisture content of the soil, etc. Climatic conditions of the region
such as rate of precipitation, humidity etc. also contribute to this factor.

Consumption of wood
Figure 30: Timber stored for firing
initiation.

Source: Author

In Guwahati, on an average, 38.30 T ofwood is being used in the initial firing
process along with the rubber tyres thatare procured from local scrap markets.
In Silchar it was observed that 53.27
T of wood was being used whereas inDibrugarh, the average consumption wasaround 50.72 T. It can be observed thatbrick kilns in Guwahati are consuming
less wood as compared to that of Silchar
and Dibrugarh while the average brickproduction is almost in the same range.
This may be due to variations in thequality of locally available timber in termsof calorific value as well as moisture
content.

3.2.6 Environmental Impact(a) Environmental scenario
The brick industry in Assam is based on widespread production activity which is energyintensive, resource-depleting and highly polluting. One of the major pollutants emitted froma FCBTK and other brick kilns are Suspended Particulate Matter (SPM). These are generated
due to the firing practices being adopted. In FCBTK firing practises the coal is fed from thetop. To reduce the drudgery of labour working in high heat conditions, it is a practice to put inhigh amounts of coal. This results in incomplete combustion and therefore release of black
carbon and high particulate matter. Due to the high amount of sulphur in the coals of North
East India it is also expected that the release of SO2 in the atmosphere will also be very high.
Considerably high levels of pollution are evident at each and every stage of the production
process in the kilns. The high levels of brick dust during the loading and unloading process

40 | Pre-Feasibility Studies for Implementation of Green Brick Production

creates potential health hazards, thereby reducing the life expectancy of brick workers to alarge extent.
Judging by the amount of smoke released to the atmosphere, pollution is a big concern inthe brick kilns. Apart from workplace pollution, one of the major issues from burning fuelis the creation of numerous by-products, some of which may be useful and others that are
undesirable, irritating or dangerous. Wood burning creates particulate air pollution that cancontribute to human health problems and increased hospital admissions for asthma andheart diseases. Wood burning smoke pollutants include nitrogen oxide, sulphur dioxide,
volatile organics, radioactive compounds, carbon monoxide, formaldehyde and suspect
carcinogens (polycyclic aromatics and dioxins).
Figure 31: Estimated CO2 emissions for study areas

CO2 emission 0.215 million
tonne (estimated)
Guwahati cluster
129 (based on PCBA data)

Dibrugarh cluster
90 (based on PCBA data)
CO2 emission
0.15 million tonne (estimated)

Silchar cluster
80 (based on PCBA data)
CO2 emission
1.33 lakh tonne (estimated)

Source : Modified from mapsofindia.com

It is suggested that in the future a comprehensive emission monitoring exercise is undertaken
along with airflow modelling to understand the effect of high pollution from brick kilns. Thishas to be monitored in various seasons also to gather comprehensive data.
In addition to the above based on the data on the number of brick kilns an estimation of
CO2 being emitted from brick kilns has been presented in Chapter 4. A preliminary estimate(Figure 31) in the priority brick kiln clusters surveyed is also presented above.
(b) Energy scenario
According to feedback received from various FCBTK and Zig Zag kiln entrepreneurs during
the feasibility study, energy consumption differs significantly in almost all the FCBTK. Thisis evident from the variation in coal consumption across both the technologies in various
areas.
Although the variation is not much, it depends majorly on the type of coal, soil used andthe atmospheric conditions like humidity etc. Table 10 below gives the calorific value of thecoals being used in various regions and the specific energy consumption across the various
regions. It is pertinent to mention that coal in Guwahati is accessed through dealers whichstock coal of various varieties. The coals vary in quality as shown in Table 6. In Silchar andDibrugarh no such coal depot exists and all are sourced illegally as mentioned earlier. It is

Pre-Feasibility Studies for Implementation of Green Brick Production | 41

evident that there are low value coals available in various places in Assam. If they are of nouse in high value applications, then can be easily used as internal fuels.
The coals being used by private entrepreneurs are quite consistent. Although no testinghas been done, we presume that the choice of coal and the quality is based on energy
consumption in the brick kilns. Thus an average of 29.21 MJ/kg energy value has been
assumed in all calculations. The Table 11 below shows the Specific Energy Consumption of
the two practised technologies based on the coal consumption.
Table 10: Coal quality in AssamSl

Cluster1

Guwahati depot

2

Calorific value Ash content(MJ/kg)(%)

Sourced from Meghalaya (not disclosed)

34.52

6

Sourced from Assam (Garampani)

14.19

55

Sourced from Nagaland (Margharita)

24.38

28

HBI (sourced from Meghalaya)

28.30

7

SMB (sourced from Nagaland)

30.13

21

FCBTK in Guwahati

Table 11: Specific Energy Consumption for fired bricks

Coal consumption
Ton/lakh of fired bricks

Specific Energy Consumption(MJ/kg of fired bricks)

FCBTK

17.17

1.52

Zig Zag

16.00

1.42

FCBTK

20.41

2.21

Zig Zag

18.00

1.95

FCBTK

18.67

1.56

Zig Zag

15.27

1.27

Sl.

Cluster1

Guwahati

2

3

SilcharDibrugarh

The SEC of Silchar overall seems to be quite high compared to the other regions. Thesemight be due to excess moisture in coal or bricks and also high consumption of coal to
dry off excess moisture in the kiln surfaces. Overall the SEC in FCBTK seems to be quite
high compared to existing sources. Generally under Indian conditions, the SEC in a wellmanaged and properly fired FCBTK ranges between 1.10-1.20 MJ/kg of fired bricks. Thus theenergy consumption across all the clusters seems to be very high. The following measures
if undertaken will reduce the SEC resulting in greater energy efficiencies, reduced pollution
load and increased profitability. Some of the measures are:•Use of dry coal as much as possible. Stock the coal in a raised platform and cover it witha black plastic to avoid moisture gain.

42 | Pre-Feasibility Studies for Implementation of Green Brick Production•Use of dry unfired bricks as far as possible. Although bricks seem to be dry from outside,
more than often they are wet from inside containing moisture in the excess of 5%.
Generally, as a thumb rule, to dry off 1% moisture we spend 3% of energy.

•

Use of proper firing and feeding practice•Construction of kilns in higher areas i.e. where the water table is low. This will result inquick drying of the kiln firing area resulting in savings of energy.

•

Proper insulation covers to be followed in the kiln firing area to avoid heat loss andconservation of energy.

3.2.7 Social conditions
Migration factor
Migration of labour and moulders was one of the dominating factors in the brick productionof Assam. It was seen that the fire-masters in most kilns come from Uttar Pradesh andmoulders involved in unfired brick moulding, transportation from field to kiln, handling of
fired bricks are generally from local areas of Guwahati, Silchar and Dibrugarh depending
upon where the kiln is located along with labourers coming from various clusters of Assam,
West Bengal and Bihar such as Patna, Dhubri, Gwalpara, Cooch Behar and Barpeta.
Figure 32: map showing migration of moulders and firemen

Moulders/labourers migration
Firemen migration

Source : Modified from mapsofindia.com

Due to the migration factor and low literacy rate in the state, in some of the brick kilns it was
identified that contractors or the managers are mostly not equipped with proper technicalknowledge in terms of processes and quantities of the raw materials such as coal during thefiring process. As a result, the quality of brick produced is not suitably good, degrading theenvironment and also adding to the GHG emission.

Pre-Feasibility Studies for Implementation of Green Brick Production | 43

Working Conditions
The working conditions in the kilns are quite extreme especially during the firing of bricks.
The kilns are often operational 24x7 for this process as the heat needs to be provided to thebricks in a continuous manner leading to long working hours for labourers extending beyond
the ideal range of 7-8 hours. It was also observed that in the production and manufacturingof red bricks, there are three categories of workforce that were being involved. These weregreen brick making moulders, transportation of green bricks from field to kiln and kiln tofield followed by stacking and firing. Majority of male population is involved in the process oftransporting green bricks and firing, while the women are mostly involved in the mixing andmoulding process.
In the overall process of brick making, the ratio of men to women is approximately 70:
30 which is the same for almost all the kilns that were observed in Guwahati, Silchar andDibrugarh. In a few brick kilns it was observed that the masons who were involved in theprocess of manufacturing bricks resided in the temporary or permanent shelters along with
their family members including children. In some instances, children could be seen helping
out in the brick-making process, assisting their parents for small tasks.

Living Conditions
While documenting brick kilns, it was observed that basic amenities such as toilets,
temporary housing, and drinking water system were being provided by the brick kiln owners
in almost all the kilns. In one of the FCBTK based in Silchar, permanent housing had been
built for the workers along with toilets. In most kilns, temporary shelters were made withthatched roofs, bricks for walling, bamboo for roofing support, etc. and were built by theworkers themselves. The waste from the toilets was being stored in the soak pit and no directdischarge of the waste into the river was observed. For drinking water purposes, bore wellsystems were available in most of the kilns for the labourers which were also being used forother domestic chores. Health and safety equipment such as gloves, helmet, eye glasses,
boots etc. were not provided for workers in most kilns.

3.2.8 Economics of brick production
Based on the production rate of the bricks, the wage type has been categorised into twosystems i.e. monthly salaries and contractual per thousand bricks. The daily and monthly
wages of the labourers varies from place to place. It can be observed that in Silchar, themonthly salary of the manager is starting comparatively from a lower range to that of
Guwahati and Dibrugarh. Whereas for the process of green brick making and moulding,the daily wages in Guwahati region is lower compared to the other two regions. No criticalvariations could be seen for the process of transportation, with costs being more or less thesame in all three regions.
Table 12:Wages for different processes in brick making

Occupation

Wage typeManager
Fire master
Site supervisor

MonthlysalaryGuwahati(INR)

Silchar(INR)

Dibrugarh(INR)

12,000 -15,000

8,000 -1,6000

1,000 -13,000

11,000 -15,000

10,000 -15,000

13,000 -15,000

10,000 -11,000

10,000 -11,000

10,000 -11,000

44 | Pre-Feasibility Studies for Implementation of Green Brick Production

Occupation

Wage type

Unfired brick making(mixing + moulding)Transportation
charge for unfired
brick from field tokiln:
Transportation
charge for unfired
brick from kiln tostacking yard

Guwahati(INR)

Silchar(INR)

Dibrugarh(INR)

150 - 900

1,000 - 1,500

800 – 1,200

350 - 700

280 - 450

350 - 400

300 - 450

Contractual
250 - 380
perthousandbricks280 - 360

Based on the data collected on wages and costs for raw materials, an estimate of the actual
production cost has been presented in the table below. It can be seen that the average
cost of production of one thousand bricks is approximately INR 5,735 or INR 5.73 per brick.
Depending on the quality and local demand for bricks, the selling price for fired bricks inmost regions was around INR 9-10.
Table 13:Estimated production cost for bricks

Parameters (per 1000 bricks)

Cost (in INR)

Soil

1200

Brick moulding releasing sand150

Unfired brick production

800

Transportation and Loading of unfired bricks

250

Unloading and transportation fired bricks

350

Fuel

2650

Fire master

280

Electricity

30

Diesel5

Maintenance20

Total production cost (per thousand bricks)

5735

3.2.9 Regulatory frameworks
There are several regulatory frameworks that apply to the brick sector in Assam including
those by the Pollution Control Board, Ministry of Environment, Forest, and Climate Change,
as well as the Energy Conservation Building Code. These have been detailed out in thefollowing sub-sections:(i) Pollution Control Board
In order to decrease pollution from brick kilns to the bare minimum, the PCBA has notified
guidelines for brick manufacturing in the state. The guidelines provide guidance on competentauthority, land location, plant and machinery location, standards to be achieved, pollution
control measures required, operation and maintenance, and general conditions. Apart fromthis the guidelines also provide guidance on procedure to apply for establishment consent,
operation consent, consent renewal, reporting mechanism, penalties for non-compliance,and conditions for consent revocation.

Pre-Feasibility Studies for Implementation of Green Brick Production | 45

Location of Land
The guidelines have provided distance requirements of the plant from several entities. A
brick kiln must be at least 300 metres and 500 metres away from a residential area with apopulation of 100-150 people and more than 150 people respectively. The distance from thenotified municipal area/town committee shall not be less than 1.0 km. The brick kiln should
be beyond an aerial distance of 500 metres from hospitals, schools, public places, religious
places, and from places where flammable items are stored. It is restricted to establish brickkilns within a 1km radius of notified sensitive areas like zoos, sanctuary and so on. Further
the brick kilns should be at least 200 metres away from the nearest railway tracks and 500
metres away from the natural path of water flows. According to the guidelines, the brick kiln’scollection/excavation area should not be within the restriction limits set out in Rule 7 of theAssam Minor Mineral Concession Rules, 2013. The guidelines have specified the minimum
permissible distance between two kilns to be 500 metres. The guidelines have restricted theestablishment of brick kilns in the ‘No-Development Zone’. According to the guideline, after
reviewing the proponent’s application, the Board’s Regional Office will convene a public
hearing in the relevant Gram Panchayat to determine whether the industry is acceptable tothe local community or not.

Location of plant and machinery
As per the guidelines, the land should be vast enough that after establishing the plant andreserving space for material stock and vehicle movement, there should be enough space toplant at least two rows of trees, shrubs or bamboo along the periphery.

Standards to be achieved
The rule has mandated compliance of brick kiln units to the standards notified by Ministry ofEnvironment & Forests (MoEF), Govt. of India under Schedule I at Sl. No. 74 of Environment(Protection) Rules and Notified National Ambient Air Quality Standards for activities involved
like mining, quarrying of clay, handling & transportation of raw material or bricks and so on.

Pollution Control Measures Required
Further the guidelines provide instructions to support the abatement of pollution suchas specification for approach roads and haul roads within the premises of brick kiln,
specification for chimney or stack usage of crushed coal for better burning efficiency, andstaggered brick laying for baking to entrap maximum particulate matter at the source. It
also recommends the usage of a properly designed gravity chamber, installation of water
sprayers, and upward alignment of the exhausts of trucks for transportation of materials
within the site. The guidelines mandates establishing wheel cleaning facilities for delivery
trucks for the removal of mud.

Operation and maintenanceFor efficient operation of the unit, the guidelines recommend establishing a water storage
facility of capacity of at least 3000 litres at the brick kiln site. It mandates a high standard ofhousekeeping. Any equipment / machinery that is malfunctioning or breakdown leading toabnormal emissions should be dealt with promptly.

General Conditions
Apart from these specific conditions the rule also provides general conditions on reporting
mechanism, usage of local agri-waste as fuel, waste that cannot be used as fuel, standard
design to be installed, and other general conditions the brick kiln should comply with.
Brick kiln owners should arrange facilities to avoid noise pollution. The brick kiln industry
46 | Pre-Feasibility Studies for Implementation of Green Brick Production

should have a reliable source of raw materials, either in its own possession or through lawfularrangements. The guidelines mandates use of fly ash in brick moulding in compliancewith the notification issued under the provision of Environment (Protection) Act, 1986 to
manufacture soil – fly ash brick.

Green Belt Development
To protect the environment from negative impacts of pollution, the guidelines mandatethat a minimum of 33% of the land on which industry is built or proposed to be establishedshould be covered with plantation. Along the periphery of the brick kiln, a multi-layer andmulti-storey green belt of 10 m width or two rows of bamboo shall be built, allowing two
10 m wide openings in the boundary for material and vehicle entry and exit. To limit dust
emission, a 3 m high wall should be built on the sides where land is not available for green
belt development. The minimum area required for the installation of a brick kiln with green
belt development is 5 bighas.

Reports to be submitted for monitoring
The following reports shall be submitted by the brick kiln to prove their compliance to theregulations;a)Annual compliance report of Consent conditions to the Competent Authorityb)

Annual stack emission and Ambient Air Quality Monitoring Report to the Competent
Authorityc)

Annual Environment Statement in the prescribed format as under Environment(Protection) Act 1986 to the Competent Authorityd)Annual production and dispatch details of bricks

Reclamation of brick fields
The top layer of the soil of minimum 1.5ft in depth removed during mining and establishing
the kiln should be stored safely within the brick field. This can be used for reclamation ofabandoned or depleted kiln areas at a later stage. This will help in retaining the fertility of theland used for brick manufacturing after being abandoned.

Competent Authority & Licensing Process
According to the guidelines any brick kiln proponent must attain appropriate permissions
before commissioning the plant. The kiln can be established on the owner’s land or a leased
land for not less than 10 years. Project proponents intending to establish brick kilns must
submit an application to regional Office of the Pollution Control Board to request:•

Consent to Establish (CTE) under Air (Prevention & Control of Pollution) Act, 1981 before
taking any step for establishing the brick Kiln•

Consent to Operate (CTO) before commissioning the plant(ii) Guidelines by Ministry of Environment, Forest, and Climate Change
As per the Ministry of Environment, Forest and Climate Change notification of April, 2021, “Allbuilding construction projects (Central, State & Local authorities, Govt. undertakings, other
Govt. agencies and all private agencies) located within a radius of three hundred kilometresfrom a coal or lignite based thermal power plant shall use ash bricks, tiles, sintered ash
aggregate or other ash based products, provided these are made available at prices nothigher than the price of alternative products.”

Pre-Feasibility Studies for Implementation of Green Brick Production | 47

In the case of Assam which has only one coal-based thermal power plant in Bongaigaon
and thus limited availability of fly ash, there are currently no other regulations concerning
brick manufacturing units in the region or those mandating the use of alternative building
materials instead of burnt bricks.
With regard to brick kilns, the MoEF also came out with revised guidelines based on
notification No. G.S.R. 143(E) dated 22 February 2022. The detailed notification has been
attached as Annexure 9. The notification broadly states that:•All new brick kilns shall be allowed only with zig-zag technology or vertical shaft or useof Piped Natural Gas as fuel in brick making and shall comply with these standards as
stipulated in the notification.

•

The existing brick kilns which are not following zig-zag technology or vertical shaft or
use Piped Natural Gas as fuel in brick making shall be converted to zig-zag technology orvertical shaft or use Piped Natural Gas as fuel in brick making within a period ofa.

one year in case of kilns located within ten kilometre radius of non-attainment
cities as defined by Central Pollution Control Boardb.

two years for other areas. Further, in cases where Central Pollution Control Board/State Pollution Control Boards/Pollution Control Committees have separately laid
down timelines for conversion, such orders shall prevail•

All brick kilns shall use only approved fuel such as Piped Natural Gas, coal, fire wood
and/or agricultural residues. Use of pet coke, tyres, plastic, hazardous waste shall not
be allowed in brick kilns.

•

Brick kilns shall construct permanent facilities (port hole and platform) as per the norms
or design laid down by the Central Pollution Control Board for monitoring of emissions.

•

Particulate Matter (PM) results shall be normalised at 4% CO2 as below:
PM (normalised) = (PM (measured)x 4%)/ (% of CO2 measured in stack), no normalisationin case CO2 measured ≥ 4%. Stack height (in metre) shall also be calculated by formula
H=14Q0.3 (where Q is SO2 emission rate in kg/hr), and the maximum of two shall apply.

•

Brick kilns should be established at a minimum distance of 0.8 kilometre from habitationand fruit orchards. State Pollution Control Boards/Pollution Control Committees may
make siting criteria stringent considering proximity to habitation, population density,
water bodies, sensitive receptors, etc.

•

Brick kilns should be established at a minimum distance of one kilometre from anexisting brick kiln to avoid clustering of kilns in an area.

•

Brick kilns shall follow process emission/fugitive dust emission control guidelines asprescribed by concerned State Pollution Control Boards/Pollution Control Committees.

•

The ash generated in the brick kilns shall be fully utilised in-house in brick making.

•All necessary approvals from the concerned authorities including mining departmentof the concerned State or Union Territory shall be obtained for extracting the soil to be
used for brick making in the brick kiln.

•

The brick kiln owners shall ensure that the road utilised for transporting raw materials
or bricks are paved roads.

•

Vehicles shall be covered during transportation of raw material/bricks.

48 | Pre-Feasibility Studies for Implementation of Green Brick Production

(iii) Energy Conservation Building Code (ECBC)
Assam is moving towards adoption of the ECBC 2017 with code amendments and plans for
its notification. The Assam draft code is currently under public review and comment. The
state is yet to incorporate the code into the state bylaws or develop a compliance system.
The state plans to form technical and policy committees with urban local bodies for
integration of the code into the building bylaws. The Assam State Designated Authority is
the Assam Energy Development Agency. Adoption of the code in the future may also have
implications for the brick industry with respect to permissible emissions, availability of raw
materials and the overall demand for bricks in both public and private sector developments.
Unlike other states, there are in-significant fly ash producing thermal power plants in Assam.
Thus most of the rules for banning clay bricks and adopting fly ash bricks are not possible in
Assam. It is clear that burnt clay bricks will continue to be the mainstay in providing wallingmaterials in the absence of viable alternatives. To regulate the burnt clay brick industry andtransform it into an energy efficient and environment friendly process, it is suggested that
PCBA issues notification and guidelines to restrict the particulate matter in stack emissionsof brick kilns to 250 mg/Nm3 as stated in the MoEF guidelines. The three technologies to besuggested are:•Natural draught zig zag kiln•

Vertical shaft brick kiln•

Internal fuel use in the green unfired making process.

Pre-Feasibility Studies for Implementation of Green Brick Production | 49

50 | Pre-Feasibility Studies for Implementation of Green Brick Production

4

4. Resource andemissions

Pre-Feasibility Studies for Implementation of Green Brick Production | 51

4.1 Soil usage
At present, most of the brick production in Assam is based on FCBTK technology. FCBTK
produces only burnt clay bricks and the only raw material being used in making the bricks
is agricultural topsoil which is being dug out from nearby agricultural land. This creates anenormous pressure on the land use pattern since it takes millions of years to regenerate
the soil. The map given below (Figure 33(a)) gives a perspective on the proliferation of brickkilns and soil usage over more than a decade of time span. The soil usage figures are from
Dumardaha, Dhubri district and have been taken from google earth map.
Figure 33(a): Figure showing proliferation of brick kilns and resultant land use
pattern in Dumardaha, Dhubri district of Assam from 2003 to 2018

Image source :Modified from Google earth

4.1.1 Brick production and land use trends
The proliferation of brick kilns in Assam is accompanied by substantial land diversion
for kiln use and increasing soil mining for the same purpose, which has been increasing
substantially over the years. The graphs below track this growing trend, in order to establish
the correlation between the two. These trends have been estimated based on calculations
since on-ground plotting of soil excavation was not carried out.

52 | Pre-Feasibility Studies for Implementation of Green Brick Production

Fig 33 ( b) Graph showing the trend of
soil mining by brick kiln manufacturers

Fig 33(c) Graph showing trend of landarea used for brick production.

From the above two graphs (Fig. 33(b) and 33(c)), it is clear that the trend of projections
has an R-Square value greater than 0.8, confirming a strong effect size and good correlation.
Thus if trends are projected beyond 2018, then the same unit area, having 8 to 9 brick kilns
at present, will have around 12 brick kilns by 2030 consuming around 58 hectares of land ona year-to-year basis.
Although the above analysis is representative of the brick making activity in Assam, it
is apparent that the growth of brick kilns has been high over the past decades. The soil
consumption pattern is proportional to the growth of brick kilns. It can be assumed in thelast couple of years that the rate of soil consumption for brick making may have decreasedon account of the COVID-19 pandemic since the actual areas used for brick making activity
could not be plotted.
At present there are 12426 bricks kilns (considering 31 districts only). Considering an average
production of 30 lakh7 bricks per year the total soil usage is around 96.88 lakh tonne of soil
mined from an area of 62108 acres of land equivalent to around 25 km2. Thus each and every
year an equivalent area of agricultural land is being used up for brick making. Till date withthe unabated brick making activity in the state, around 215 km2 of agricultural topsoil has
been lost to brick making, which is equivalent to the area of Guwahati alone. This calculation
has been done during the period 2012-2022 only, since figures before 2012 were not available
at the time of this study. Thus the actual area lost may be much more.
With growing trends in brick consumption and production and no alternative building
materials in sight, the brick making activity is slated to cumulatively consume about 593
km2 of agricultural land by 2030 and 3101 km2 of agricultural land by 2050. Such a hugeamount of land use for brick making is bound to affect the food grain production in the stateof Assam. Apart from food grain, this land use pattern is bound to have an effect on the flood
situation in the state of Assam and water logging issues.
It would therefore be desirable to study soil usage patterns in relation to top soil excavation
for brick making in order to scientifically analyse the land use patterns and the corresponding
effect on agricultural activity and food grain production.

4.2 Emissions in the brick sector of Assam
Although energy and environmental monitoring was not part of the scope of this study, a fairestimate and analysis of the emissions trend has been initiated based on secondary data
and relevant literature9. This was undertaken to establish links with climate change and GHG

6
7
8
9

As per data received from PCBA
Based on average brick production as per field data
1 acre of land dug upto 1 ft produces 6,00,000 bricks. Assumption based on field experience
Brick kiln performance assessment, Shakti Sustainable Energy Foundation

Pre-Feasibility Studies for Implementation of Green Brick Production | 53

emissions, since they bear a direct causal relation. The results of this extrapolation havebeen presented in the following section using the parameters described below.

4.2.1 Parameters used for emissions studyi.

Suspended Particulate Matter (PM2.5)
Suspended Particulate Matter (SPM) is a term used for airborne particles of diameter lessthan 100 μm. The emission factor assumed in terms of g/kg of fired brick for SPM in this study
is 0.86 g/kg of fired brick. This is based on a published report from Shakti Sustainable Energy
Foundation (2012) and is based on field measurements.

ii. Particulate Matter (PM2.5)
Emission norms in India do not address PM2.5 specifically, but it is frequently monitored
because of its environmental and health effects. Fine particulate matter (diameters lessthan 2.5 μm) can penetrate more deeply into lungs than larger particles. It also has a longer
atmospheric lifetime and a disproportionately greater effect on visibility and climate, relative
to larger particles. The values assumed for calculations are given in Table 8.
iii. Gaseous pollutants
Estimations were also made for sulphur dioxide (SO2). Table 8 provides the emission factors
for SO2 normalised to grams of pollutant/kg of fired brick. SO2 emissions stem from thesulphur content of fuel; therefore, significant variations in the SO2 concentration are possible.
Especially the coal in the North East has high sulphur content and the results might increase.
iv. Black carbon
Black carbon (BC) is a combustion product predominantly composed of strongly bonded
graphitic-like carbon rings. This composition causes black carbon to be thermally stable athigh temperatures and to strongly absorb visible light, causing warming. Organic carbon(OC) comprises all carbon species that are neither black nor carbonate carbon.
In November 2011, the United Nations Environmental Program in its assessment, Nearterm Climate Protection and Clean Air Benefits: Actions for Controlling Short-Lived Climate
Forcers, proposed replacing traditional brick kilns with more efficient ones, particularly
VSBKs, as a measure to reduce BC.

4.2.2 GHG emission results
As per data received from Pollution Control Board of Assam (PCBA), the total number ofbrick kilns across the 35 districts in Assam are 1242 (excluding the districts of Dima Hasao,
East Karbi Anglong, Chirang, South Salmara-Mankachar & Dhemaji). These 1242 kilns, on anaverage produce 30 lakh bricks per year and, emit over 2 million tonnes (20,69,357 tonnes)
CO2 of GHG emissions (assuming the weight of each fired brick to be 2.60 kg). The results are
given in the following table (Table 14) while the emissions of gaseous pollutants from FCBTK
brick kilns are shown in Table 15.
Table 14:GHG emissions in the brick sector of Assam

Parameters

Total emission (tCO2/year)

Total emission from combustion of fuel used in brick firing 19,63,220
Total emission from transportation of coal

44,291

Total emission from transport of fired bricks

61,846

Total annual GHG emissions

20,69,357

54 | Pre-Feasibility Studies for Implementation of Green Brick Production

Table 15:Gaseous emissions in the brick sector of Assam

PM2.5

SO2

Elemental
Carbon

0.18

0.66

0.13

(g/kg)(g/kg)(g/kg)

6.71 tons

1.40 tons

5.15 tons

1.01 tons

Total emission for 1242 FCBTK 8,333.82
in Assam
tons

1,738.80
tons

6,396.30
tons

1,254.42 tons

ParametersSPM

FCBTK emission factor

0.86 (g/kg)

Total emission from 1 FCBTKFrom the above two tables, it is clear that the emissions from the brick sector are tremendous,
especially when viewed from the life cycle and embodied carbon perspective. It is therefore
recommended that a more detailed GHG inventorisation study of the brick sector in Assamis carried out to understand in detail the scenario and understand the measures to mitigate
the same.

Pre-Feasibility Studies for Implementation of Green Brick Production | 55

56 | Pre-Feasibility Studies for Implementation of Green Brick Production

5
5. Alternativetechnology
options

Pre-Feasibility Studies for Implementation of Green Brick Production | 57

Based on the field surveys and the data analysed, two possible pathways of alternative
options have emerged. These are:

Improvement of existing firing practices
It has been seen that in the three large brick making clusters of Guwahati, Dibrugarh andSilchar majority of the brick kilns are FCBTK. Sporadic occurrences of Zig Zag kilns were seen
which are not very effective in terms of energy reduction or environmental efficiencies. Thereis still scope for reducing energy consumption by improvement of existing firing practices orintroducing internal fuel in unfired brick making.

Introduction of transformative new technologies
Based on the resources available e.g. various types of soil, wastes and alternate biomass
based fuels, there are quite a number of technology choices and alternatives. The alternativetechnology options mentioned in the report are not only for the three brick making clusters
but should be looked at from the perspective of the State of Assam.

5.1 Identified alternative materials and technologies
5.1.1 Improvement in existing firing practices
Better feeding, firing and operating practices:
Pollution control and energy conservation are inter-related in brick kilns. The combination ofenergy saving and reduction in pollution is a win-win situation, in which the brick kilns benefit
because of saving in energy costs and better working conditions and the society gains due toreduction in pollution and conservation of precious energy resources. But this can happen
only if the pollution control packages and energy efficient operations are sincerely followed.
New approach to operational practices requires a paradigm shift, integrating the wholeprocess innovations with new patterns of technology designs. The technology innovations
and trained human resources are a valuable asset, but the advantage of all this can only betaken if the workforce is ready to change its mindset. All this requires training of firing men
and making them learn and adopt the improved technology options.
Some of the better feeding, firing and operating practices that can be adopted for Assam inexisting fixed chimney BTK’s are innovations in:•

Storage of coal
Coal must always be stored in covered places and not in the open. This is to prevent highmoisture content due to sudden rainfall as prevalent in Assam. High moisture content lowers
the ignition quality of the coal and increases fuel consumption. Exposure to high intensity
rainfall may also cause the coal, especially the finer particles, to wash out and lead to lossof material.

•

Size of coal
The coal should have a size gradation. It should be bigger than 2 inch. The size of coal shalldepend on the type of the kiln with possible requirement of finer sizes and powdered form incertain cases, which must be based on proper analysis as per quality of coal and type of kiln.

•

Size of spoon
The spoon should have a capacity of 250 gms. This is to enable continuous feeding of coal. A
standard size of the spoon must be selected and used to ensure uniform feeding throughout
operations and reduce overfeeding or under-feeding during the firing process.

58 | Pre-Feasibility Studies for Implementation of Green Brick Production

•Feeding pattern and interval
Feeding should start from the first firing hole from the periphery and then return back. It
should ideally be done in a Z-pattern.

•Role of chimney
The chimney should be a minimum of 100ft in height with good construction. The size mayvary based on the type of kiln. For instance, higher chimneys may be required for zigzag kilns.
This must be based on proper technical inputs. Any leakages must be avoided to ensure
optimum firing operations and proper maintenance should be carried out for the structure
after every brick firing cycle.

•

Air supply
The flue gas ducts should be cleaned regularly to avoid choking of the ducts due to dust andash. This will ensure regular flow of air and a better firing process. Active measures such as
exhaust fans may be used in certain types of kilns for assisting the process.

•Damper and its operation
The closing and the opening of the dampers should be by an experienced firemaster. It
should not be kept open at all times.

•

Arresting heat losses
Proper care should be taken in spreading burnt coal ash on the top surface, use of tirpals
and regular plastering of the outer layers by insulating materials should be done to arrest
heat loss.

•

Flue damper
Flue dampers must be maintained regularly.
All the above individually will not result in any significant changes in energy consumption
and environmental emissions. However, when worked in unison will achieve the desired
results.

5.1.2 Use of internal fuels in green brick making
Internal fuels are generally waste materials with medium calorific values (1000 – 2000 KCal/kg) mixed with the soil during the unfired brick formation process. The various types ofinternal fuels recommended for use in brick making are generally waste materials e.g. boilerash, sponge iron waste, bottom ash from thermal power plants, rice husk ash and othercarbon bearing wastes. In the absence of waste materials in Assam, the coal used for firing
can be used as an internal fuel also.
Before using the same it has to be processed in a predetermined way so as to retain thecharacteristics and quality of the fired product similar to non-internal fuel bricks. Various
theoretical energy calculations need to be done to determine the quantity of internal fuel tobe mixed. Existing processes of soil selection, processing, and moulding need to be studied
for determining the most cost effective and beneficial way for mixing of internal fuel. Careshould also be taken during the above to consider social and cultural conditions. An added
advantage for Assam for adopting the technology is the use of mechanised soil mixing which
is most important during the adoption of the technology. Thus it only needs demonstrationand technical support.

Pre-Feasibility Studies for Implementation of Green Brick Production | 59

The various advantages of using waste materials as internal fuel are:•

Reduction in external coal consumption, thereby saving natural resources.

•

Uniform quality of fired material, in terms of ring, colour and strength.

•

Lower levels of pollution thereby reducing emissions and savings in greenhouse gases.

•

Utilisation of waste materials in a profitable manner thereby reducing soil consumption
and preventing solid waste pollution.

5.1.3 Transformative new technologies
The various brick firing options described in this section have all been taken from existingand practising technologies in various Asian countries. Practising technologies from othercontinents have not been described here since they do not match the socio-economic orsocio-cultural or geo-cultural characteristics of Assam. All the technologies described haverelevance to Assam and the North East and have been carefully selected after judging thepossibility of technical adaptability to Assamese conditions. No attempts have been madeto suggest the suitability of a particular technology. Choice of technology depends on manyfactors and is best left to the practitioner to decide.

5.1.4 Essential features of brick kilns
The importance of chemical reactions occurring during clay firing makes it clear that kilns are
not simply heat-generating systems but are chemical reaction vessels. To complete various
chemical and physical changes in clay and to get a good quality fired product, it is essentialthat the heating and cooling rates are controlled. In ancient times, clay products were fired in
the open, with very little control over the firing process. The requirement to control the firing
process and conserving the energy resulted in development of kilns. The word kiln is derived
from the Latin ‘culina’, meaning kitchen. As brick kiln technology developed, more and more
control on the firing process and lower energy consumption levels were achieved. The mainprocesses that occur during firing in a brick kiln are:•Heat generation through combustion of fuel•Transfer of heat generated to bricks•

Controlled heating and cooling of bricks

Combustion is generation of heat by chemical reactions that take place when a fuel is burnt.
The fuels generally contain carbon, hydrogen, oxygen, nitrogen, sulphur and ash. When fuelis burnt, carbon and hydrogen combine with the oxygen in combustion air, to form carbon
dioxide (CO2) and water (H2O) respectively. Both these chemical reactions produce heat. A
chimney (to produce natural draught) or a fan (to produce artificial draught) is employed inbrick kilns for supplying air for combustion in certain types of brick firing technologies.
In brick kilns, convection (heat transfer by virtue of fluid motion) is the main mode of heattransfer. Air initially picks up heat from hot fired bricks. It is then heated with combustionof fuel. The hot air then travels to the unfired bricks and transfers part of heat to them. Like
combustion, heat transfer is also greatly affected by airflow. It also depends on the settingof bricks in the kiln. For a brick kiln with a given raw material (clay), controls on heating andcooling are achieved by:•Control of air supply and flow•

Fuel supply•

Stacking of bricks•

Controlling heat loss to the surroundings

60 | Pre-Feasibility Studies for Implementation of Green Brick Production

5.1.5 Classification of brick kilns
A literature survey shows use of several types of kilns for firing bricks. During the several
thousand years long history of the brick industry, whenever a new kiln was designed or
modified it was given a new name. However, there are several similarities between different
kilns, which are used for classification of brick kilns:•

Intermittent and continuous categories based on the process. Continuous kilns canfurther be classified as moving fire (in which fire moves and goods are stationary) or
moving ware (bricks move, firing zone is stationary)•

Up-draught, cross-draught or down-draught, based on the direction of flow of air•

Natural (chimney) or artificial (fan) draught based on the production of draught

Classificationof brick kilns

Intermittent kilns••••

Continuous kilns
•

Clamp
Scove
ScotchDown draught

Moving fire annular kilns
Hoffman�
Bull’s Trench• Movable chimney• Fixed chimney�
Simple / Straight line
• Zig-Zag (forced draught)• Zig-Zag (natural draught)
Moving ware kilns
�•

5.2 Alternate clay brick firing technologies
The section below gives a brief overview of technologies that can be adopted for Assam.

i. High draught Zig Zag kiln:
Figure 34:
Highdraught
Zigzag Kiln

High draught kilns are normallytermed in Asia countries e.g. India,
Nepal, Bangladesh as Zig-Zag kilns. It
should be mentioned here that ZigZag is only a firing pattern followed in
High Draught kilns.
In these types of kilns, the length of thekiln gallery is increased by zig-zagging
the chambers and the fire follows azigzag path instead of a straight pathfollowed in BTK. At any point of timethese types of kilns were widely usedin developed countries particularly
in Germany and Australia. In Europe,

Pre-Feasibility Studies for Implementation of Green Brick Production | 61

Figure 35:
Firing ofbricks inhigh draught
Zigzag kiln

Figure 36:
Stackingof unfired
bricksbefore firing

the interior cross- section of the kiln used to besmall in original zigzag kilns (7.5 ft. wide x 7.5 ft.
high) and the kiln used to have 16-20 chambers
each 20-25 ft. long. Fan draught was provided
and the kiln operated on high draught at avery fast rate of fire travel (50-100 ft. per day).
The Habla kiln developed in Australia is a formof zigzag without a crown and in which thedivision walls between chambers are made of
unfired bricks. The top of the setting is coveredby a layer of two or three courses of bricks
followed by a layer of ash.
The Zig-Zag firing concept in Bangladesh is
generally introduced and if followed in theform of a High Draught (HD) kiln. The HD kiln
has several similarities with the Habla kiln.
The kiln consists of a rectangular gallery which
is divided into 24 chambers by providing
temporary partition walls with unfired bricks.
The wall of each chamber runs along the widthof the gallery except one end, wherein a space of 60 to 65 cm is left for communication to
the next chamber. Draught is created by an induced draught fan with a 20-35 HP motor for
proper combustion of fuel. Depending on the design capacity of a kiln, a chamber can hold7,500 to 15,000 bricks.
Normally two chambers are fired per day and an output of 15,000 to 30,000 bricks per day
can be obtained. When brought to full firing, the kiln operates on a draught of 50 mm Hg.
However, several problems are being encountered in the HD kiln in different countries:•

Bricks remain too hot for handling at unloading point.

•

Dampers in the flues provided in the inner wall communicating with the main central
flue being too close to the firing floor, were exposed to high heat resulting in rapid
deterioration.

•

As the draught and hence the negative pressure in the kiln is several times more thanthat observed in fixed chimney BTK’s, the HD kiln is also more susceptible to air leakage.
Most of the leakage takes place through wicket walls and through leaking valves anddampers.

Specific energy consumption of around 1.35 MJ/kg of fired bricks has been achieved in
HD kilns being operated under full capacity. However, it is generally observed that due
to shortage of trained manpower and lack of exposure to proper operating practices theperformance of HD kilns are much below the expected level of performance. Moreover, inmost of the rural areas either electricity supply is not available at brick kiln sites or the supply
is not reliable. Therefore, installation of a DG set for electricity generation becomes essential
with a High Draught kiln which further adds to the complexity of the problem.

62 | Pre-Feasibility Studies for Implementation of Green Brick Production

Figure 37: Air flow through high draught kilns

ii. Natural draught Zig Zag kiln
Natural Draught Zigzag Firing kiln is a continuous, cross draught, moving fire kiln in which the
air flows in a zigzag path due to the draught provided by a chimney. It has many similarities
with FCBTK technology; the main difference being the zigzag air flow path. Zigzag firing
concept was first used in the Buhrer kiln (Patented in 1868). The concept was later used in
Habla kilns. In India, Central Building Research Institute (CBRI) first introduced the zigzag
firing technology based on induced draught (with the help of a fan) during the early 1970’s.
As per available information, natural draught Zigzag firing technology was first used in India
in 1997 by Priya Bricks in Kolkata by modifying an existing FCBTK. The technology was
adopted by Prayag Clay Products at Varanasi and, through them, has been propagated tomore than 50 kilns by the end of 2013. It is now gaining popularity as an alternative to FCBTK
technology.
Figure 38: Natural draught Zigzag Kiln

Natural Draught Zigzag firing kiln is a moving fire kiln in which the fire moves in a closed
rectangular circuit (central perimeter 140-180 m) through the bricks stacked in the annularspace between the outer and the inner wall of the kiln. It operates under the natural draught
provided by the chimney (30 – 40 m high) located at the centre of the kiln.
The bricks are stacked in such a manner to form distinct chambers (~2 m long) and guidethe air flow in a zigzag path. Zigzag flow increases the air flow path length and turbulence

Pre-Feasibility Studies for Implementation of Green Brick Production | 63

in the air, thereby resulting in improved combustion &amp; heat transfer rate and uniform
temperature across the kiln cross section. The kiln does not have a permanent roof and bricks
stacked in the kiln are covered with a layer of ash & brick dust, which acts as a temporary roof
and inhibits the heat loss as well as seals the kiln from leakages. There are 3 distinct zones inan operating zigzag kiln:•

Brick firing zone where the fuel is fed and combustion is happening,•

Brick preheating zone (in front of the firing zone) where unfired bricks are stacked andbeing preheated by the flue gases and•Brick cooling zone (behind the firing zone) where fired bricks are cooled by the cold air
flowing into the kiln.

Some of the critical features of the technology are•

Air Inlet: Air enters into the kiln from the back end of the cooling zone which is kept open
to allow air entrance.

•

Seal to guide flue gas: Front end of the preheating zone is sealed by a plastic sheet toguide the flue gas to the chimney through the flue gas duct system.

Firing zone extends to 6 chambers (~12 m) and solid fuels like coal, firewood, agriculture
residue etc. are fed through the feed holes provided at the top of the kiln continuously bya single fireman standing on the top of the kiln. The fire travels a distance of 6-7 m in 24
hours and fires 20,000 to 50,000 bricks. Daily, fired bricks are unloaded from the front of thebrick cooling zone and an equivalent batch of unfired bricks is loaded ahead of the brickpreheating zone.
Some of the basic advantages of the natural draught zig zag kilns as stated by various
agencies are:•Natural draught zigzag kilns emit ~80% lower PM and ~90% lower Black Carbon ascompared to FCBTKs. This is mainly because of better combustion of fuel and settling ofparticulates in the kiln itself due to zigzag flow. Emission of CO2 and CO from zigzag kilns
is lower because of less consumption of fuel and improved combustion.

•

Natural draught zigzag kilns consume ~20% less fuel as compared to FCBTK because of
better combustion and heat recovery.

•

Capital cost of setting up a natural draught zigzag kiln and its production capacity range
is the same as that of a FCBTK. However, due to less fuel consumption and better productquality, the return on investment of natural draught zigzag kiln is higher than FCBTK.

•

The range of products of natural draught zigzag kiln is the same as that of FCBTK. But
due to improved combustion and uniform temperature attained throughout the kiln
cross-section in natural draught zigzag kiln, product quality is improved.

•

On OHS, natural draught zigzag kiln offers no improvement over FCBTK. Both kilns havepoor OHS conditions, which is a major shortcoming of these technologies.

iii. Hoffmann kiln(a) The original Hoffmann Kiln
The first Hoffmann kilns were in the form of a great circular ring chamber, with massive
walls and a large chimney at the centre, to which underground radial flues converged fromthe inside walls of each of the twelve chambers. The chambers were barrel arched (like arailway tunnel), and in the roof arches there were several small feed holes through whichfine coal could be fed into spaces made among the bricks to be fired. Around the outer wall

64 | Pre-Feasibility Studies for Implementation of Green Brick Production

Figure 39:
HoffmanKiln

or the kiln were the twelve openings
for loading and unloading theindividual firing chambers. Thesechambers were separated fromeach other by very large metal
dampers that could be raised andlowered as the fire moved aroundthe kiln from chamber to chamber.
Once the kiln is lit it is allowed to goout, and the sequence of operationis continuous. With the kiln in fulloperation two chambers will beopen, and the other ten sealed up at
the door and by the interconnecting
steel dampers. If the chambers
are numbered from 1 to 12, thenbricks are being unloaded from
2 and loaded in 1. The damper isclosed between 1 and 12, but opens
between all other chambers. Air isdrawn through the open door of
2 and through the bricks in 3, 4, 5,
and 6, cooling them down and at
the same time being heated itself.
The temperatures of the chambers
increase from 3 to 6, with thetemperature at 6 being close to thefiring temperature.
Chamber 7 is being fired, with fuelbeing fed at intervals through the roof, which is immediately ignited by the hot air from 6.
The products of combustion pass on to 8, 9, 10, and 11 drying and pre-firing the bricks inthese chambers. In 8, the bricks are at the pre-firing stage, and in 11 they are going throughthe water smoking stage. From 11 the combustion gases pass through the flue and up thecentral chimney. All the other 11 flues from the other chambers are closed off with dampers.
At regular intervals, the firing zone is moved forward and the corresponding changes madeto the dampers between the chambers and into the chimney. The chambers being loaded
and unloaded move forward in sequence, and this way heat is extracted from the coolingbricks and also from the hot combustion gases.
(b) The modern Hoffmann kiln
The original round Hoffman kiln is no longer in use, having been replaced by the more
modern version, which takes the form of two parallel tunnels built side by side, connectedby curved tunnels at either end. With such an arrangement, the chimney is built outside thekiln structure and may be connected to more than one kiln. Sixteen chambers are about theminimum for effective working; twenty-two chambers are preferable. The original Hoffmann
was superseded, because it had such a large heat absorbing mass, and the tapering firing
chambers were small and unnecessarily complicated to load, while the very large damper
between chambers was cumbersome and awkward to operate. This damper was replacedby the pasting of a paper or fabric screen between the sections of the firing tunnel as it isloaded. The screen seals the tunnel at this point and prevents cold air being drawn thewrong way round the kiln to the firing zone. The screen is destroyed by the approaching firing

Pre-Feasibility Studies for Implementation of Green Brick Production | 65

zone, at just the right time, as it moves around the kiln. There are now many different designsof continuous kiln, based on the moving firing zone perfected in the Hoffmann kiln, but thebasic principle of the moving firing zone, coupled with continuous loading and unloading,remains the same.
Figure 40:
Detailed planof Hoffman kiln

Figure 41:
Firing processin Hoffman
Kiln

The path of fire travel in the original Hoffmann was circular, later distorted into an ellipse, thearch of the tunnel being supported on the side walls. In order to increase output, continuous
kilns with longer circuits through which
the firing zone travels more rapidly
are built. Two firing zones runningsimultaneously are possible on thelarger kilns. To save space, the firing
circuit is bent into a Zig Zag form.
Other designs, in which the circuits
are built in the form of a T, Y or X, withthe chimney in the centre, are also
used. In principle, they do not differ
from the Hoffmann Kiln, but with ahigh rate of fire travel, assisted by astrong fan draught system, they arestill popular in some countries.
Although Hoffmann kilns use coal as
the primary fuel, in Bangladesh they
have been modified to use naturalgas. This type of fuel creates very
low levels of pollution. However,
the energy consumption is highcompared to other efficient kilns.
One of the major deterrents of thistechnology is the availability of gas
and the extremely high capital cost of the kiln. These kilns are suitable for high capacity

66 | Pre-Feasibility Studies for Implementation of Green Brick Production

consumption and high price e.g. in and around Guwahati. They are not feasible in othersmaller towns where the demands of bricks are less.
Figure 42: Process of controlling excess air(c) Achieving firing efficiency
It is important to determine where and how the heat is lost during firing, and to see what
measures can be taken to keep them as low as possible. A high proportion of the heat lost is
carried away in the combustion waste gases, and, more importantly, a lot of the waste gas
heat is carried out by the excess air passing through the kiln. The heat lost through excess
air can be as high as 50% of the total heat input. This loss can be measured by monitoring
the temperature of the waste gases going up the chimney and comparing it to the fuel: fired
brick figures.
The fuel consumed in kilograms per 1000 bricks in a continuous kiln increases from 35 at awaste gas temperature of 100°C to 75 at 300°C with 500% excess air. This figure shows theimportance of controlling the excess air: for example, at 200°C, if the excess air is increased
from 100% to 800%, for the same rise in temperature, the fuel consumption has to be morethan doubled, as most of the available heat from the fuel is going straight up the chimney.
If the waste gas temperature falls too low, it is an indication that the draught through thesystem is impaired. This introduces another set of problems, like inefficient combustion,
poor heat distribution and the condensation of flue gases on the unfired bricks, causing
discoloration. A flue gas temperature of 100°C is a reasonable temperature to work to, but if
the kiln is small, with less than 16 chambers, a temperature this low may not be obtainable.
The minimum of excess air is, of course, desirable for maximum efficiency, but some leakageof air is inevitable with such an extensive structure as a continuous kiln.
Figure 43: Features of Hoffman Kilns

The other main source of heat loss is
by radiation and convection throughthe kiln structure. One way this can be
reduced is to increase the kiln output,
because the radiation and convection ofheat remain almost constant, whether
the output is high or low. Packing morebricks into the kiln by placing the bricks
tightly together does not work, as it
tends to decrease the rate of fire travel
and leads to a higher percentage ofbricks being unevenly fired. There is abest rate of fire travel corresponding toPre-Feasibility Studies for Implementation of Green Brick Production | 67

the proportion of solid bricks to gas spaces in the kiln chamber. By reducing the brick stacking
density and using a higher draught, the rate of fire travel may be increased, which will resultin an increased output. To establish the best and most productive conditions require a lot ofexperimentation. With barrel arch and chamber kilns, radiation and convection losses fromthe kiln structure are usually kept down by building the wall a metre or so thick, throughwhich the heat penetrates slowly. It is true that the thicker the walls the more heat is required
to raise the kiln to top temperature, but in continuous kilns this heat is largely recovered.
A large heat capacity in a kiln structure, however, reduces the rate of natural cooling, so achamber of fired bricks will be too hot to unload for a long time. Extra insulation on the
top of a kiln will reduce the heat and make the working conditions for the kiln stokers more
pleasant. It will also reduce the rate of cooling. If lower density insulation material is used toreplace high density firebrick, then heat losses will be reduced at the same time as throughdraught cooling time. This is because of the lower heat absorption and retention of theinsulation material.
There is also a case for insulating the base of continuous kilns; less heat will pass into thefoundations during high temperatures, so the reservoir of heat that returns into the kiln
during cooling would be reduced. On all types of kilns, careful maintenance is the firstrequisite for efficient working. The brickwork of all kilns must be kept in good repair. Cracks
let unwanted cold air in and greatly facilitate heat loss during firing. When the doors of thekilns are sealed up, this should be done with double thickness brick, preferable with aninsulation space between them and a good layer of clay slurry plastered across the outside
for sealant. Level top firing floors indicate structural soundness and lower heat losses. With
intermittent kilns, it is important to see that flues are kept clean, that dampers fit and seal
well and that the chamber floors are level and clean. The positioning of the unfired bricks
during loading needs to be done accurately, or increased brick wastage will result.
(d) Advantages of Hoffmann kilns:•

They are fuel efficient, because of the direct stoking into the bricks and their use of waste
heat to dry and preheat the unfired bricks before firing. Efficiency figures for Hoffmannkilns using coal as a fuel, in England and China, range from 1,800 at best to 2,350 kJ per
kg fired brick at worst.

•

They have the capacity to fire very large quantities of bricks evenly and with minimal
wastage.

•

The use of the down or cross draught system, with the fuel being burnt at regularintervals amongst the bricks, provides an even firing throughout the kiln.

•

The firing is controllable by the use of the dampers and careful stoking.

•A variety of biomass fuels can be used successfully, for example, sawdust and woodprocessing waste, rice and coffee husk. These fuels can be added through the roof of
the kiln with the use of mechanised fuel charging hoppers that run on compressed air
or electricity. This is necessary when burning the biomass fuels that have a higher massand lower calorific value than other fuels, like coal or coke.

(e) Disadvantages of Hoffmann kilns:•

They have a large mass that absorbs a lot of heat as the firing zone moves forward
through the cold kiln. This is compensated by the fact that some of the residual heat in
the kiln and fired bricks is used to preheat the air for combustion.

•

They are expensive to build and require regular maintenance. Some models are large
and complicated structures with very intricate systems of flues and dampers.

68 | Pre-Feasibility Studies for Implementation of Green Brick Production

•

They occupy a lot of space; because of this they are often built in the clay pit after all theusable clay has been extracted, so as not to occupy large areas of clay reserves.

•

Direct stoking affects the quality of the bricks directly beneath the stoke holes. Thesebricks can be over fired and are usually discoloured. This can be avoided by incorporating
firing trenches beneath the stoking holes, along the sides and in the centre of the firing
chamber. These trenches contain the burning fuel and prevent localised brick spoilage
in the kiln. The fitting of firing trenches, however, means that the capacity of the kiln is
reduced to produce a higher quantity of evenly fired bricks.

iv. Down draft kiln:
A downdraft kiln consists of three basic structural elements. The firebox, where fuelcombustion takes place; the stacking area, where bricks are placed; and the kiln chimney,which includes the flue damper system. Since the basic principle of a downdraft kiln entails
directing flame downward inside the kiln, and not upward, the firebox is usually a separate
section, located apart from the brick stacking area.
Figure 44: Operating mechanism of down
draft kiln

The firebox is usually located on
one side of the kiln. The function of
the chimney is to create a draft for
the flame in the firebox so that theflame is drawn through the bricks
in the stack area. The height of thechimney, plus its diameter, is directly
related to the size of the kiln if theproper draft is to be created. For
the purpose of reduction, fuel backpressure within the kiln is controlledwith the damper, which is locatedat the bottom of the kiln chimney.
The damper is handled in much thesame way as for updraft kilns, but
it is important to understand othercharacteristics of a downdraft kiln inorder to control reduction during thefiring cycle.

During firing, time is needed during
the early portion of the firing cycle
for the firebox area to be heated.
This is done before the brick stacking
area reaches any substantial
temperature. At the onset of a firing
it is difficult to acquire even a little
draft within the kiln to draw the flameup from the burners because the kiln chimney is at some distance from the firebox. One
actual advantage of such a firebox arrangement, however, is that the bricks are protectedfrom being licked by flame in the early part of the firing cycle. Once heat has begun to build
up within the kiln, a substantial draft usually occurs if the damper is wide open. As heat
continues to build up, the damper is regulated to achieve maximum efficiency.
Since the kiln itself is a retaining box for heat, a system that will generate heat must be
provided. One must understand burners and the basic types of fuels that burners use in orderto reach a given temperature within the kiln. Kilns constructed with ceramic fibre materials
Pre-Feasibility Studies for Implementation of Green Brick Production | 69

provide such excellent insulation that the heat input needed is considerably less than forconventional brick kilns and there is a resulting saving of fuel. Generally it takes 7-8 days forcompleting a firing cycle. One day to load the kiln, 2 days to heat to optimum temperature, 1
day for soaking and another 3-4 days for cooling before they can be taken out. The capacity
depends on the kiln size and ranges between 12,000 – 25,000 bricks per charge.

v. Chamber kiln
For not so well educated labourers,
there are many technical constraints
to be considered in the working of abrick firing kiln. The construction andoperation of the kiln must be technicallyapplicable and acceptable by both
entrepreneurs and workers. The kiln
must be economically feasible andcompetitive compared to the existingkilns.

Figure 45: Chamber kiln

Energy efficiency is the key word fordevelopment and operation of any kiln.
Similarly, batch operation is preferable
because of the limited production scale to supply local markets only. The fluctuation of brickdemand, with the peak always in dry season, makes the batch production more suitable
than the continuous process.
Figure 46: Design of chamber kilnwoodfiringdamperA
D

Stack or blower

cooling

Fresh airBpreheatingC
dryingFresh airBased on the above-mentioned requirements and constraints, a new kiln has been underoperation in India and other countries and is appropriately termed as “Chamber Kiln”. The
kiln consists of four down-draft chambers which take turns to serve the four processes

70 | Pre-Feasibility Studies for Implementation of Green Brick Production

namely; cooling, firing, preheating and drying. The combustion air of the firing chamber ispreheated by the cooling process in the preceding chamber. The exhaust gas from the firing
chamber is channelled to preheat and dry the bricks in the next two chambers. Both thebricks and the combustion air are preheated, thus resulting in less firewood consumption
in the firing process. Heat lost to the atmosphere is relatively low in comparison to the
traditional batch firing. The four chambers are interconnected by a duct network. A blower
is installed at the end of the duct to induce draft for the system. After chamber A finishes thefiring process, it will become the cooling chamber and later on drying and preheating, andso on for other chambers.
One can imagine that different processes (in the four chambers) required different processing
times. The brick temperature in the cooling chamber is reduced from 900 o C to less than
100 o C, while the temperature lift in the firing chamber is from 400 o C to 900 o C. The
corresponding figures for the preheating and drying chambers are 100 o C to 400 o C and
30 o C to 100 o C, respectively. There is no doubt that cooling is the longest process. Unlessa strategic time matching operation is worked out, the proposed kiln is not functional.
The capacity of each chamber is around 2,200 bricks, the production rate is about 50,00070,000 bricks per month depending on the firing temperature and combustion air flow rate.
Moreover, this kiln can be operated by about 3-4 workers all the time. The fuel used is coal.
However, waste biomass e.g. rice husk, wheat straw and other biomass can also be used forfiring. Thus essentially it is a multifuel kiln.

vi. Tunnel kiln:
The first version of the Tunnel Kiln wasdeveloped in Germany in 1947 taking overfrom the annular and zigzag type kilns. It
is essentially a 50-100 ft. long rectangularchamber lined with high quality refractory
bricks. The bricks are loaded from one end in
a car at a predetermined pattern. After a fixedinterval of time, depending on the firing cycle,
a car is pushed from one end, simultaneously
taking one car out from the other end of thetunnel. Maximum fire zone is maintained at
the middle portion of the tunnel with a heating
and a cooling zone. The fuel used is high speed diesel or natural gas. The improvements inthe working conditions at a tunnel kiln proved to be a big advantage. There were no more
hot and dusty chambers to deal with and workers were no longer exposed to the extremechanges of temperature when loading and unloading the kiln. In winter this could mean
working between temperature differences of – 20° C in the storage area to + 50°C inside thechambers. Also of great importance for the future of the brick manufacturing industry is thatthe tunnel kiln could be ideally used for continuous production operations.

Figure 47: Tunnel Kiln

Today’s tunnel kiln is a very complex and complicated high-tech type of system, so muchso that it has been partly forgotten that a relatively simple tunnel kiln can be built that still
produces very good bricks. Tunnel kilns are most widely used in Vietnam in state sponsoredunits due to their extremely high investment cost. However, tunnel kilns are economical for
firing low mass bricks i.e. at least 40% hollow bricks. Firing of solid bricks is not economical
in a tunnel kiln.

Pre-Feasibility Studies for Implementation of Green Brick Production | 71

vii. The Vertical Shaft Brick Kiln
Vertical Shaft Brick Kiln (VSBK) technology is an energy efficient technology for firing clay
bricks. It is particularly suited to the needs of brick production in developing countries – whichis small scale and decentralised type.
Figure 48: Vertical shaft brick kiln
The evolution and initial developmentof VSBK technology took place in rural
China. The first version of VSBK in China
originated from traditional updraft
intermittent kiln during 1960’s. During
the 70’s, the kiln became popular inseveral provinces of China. In 1985, theChinese government commissioned theEnergy Research Institute of the Henan
Academy of Sciences at Zhengzhou(Henan province), to study the kiln
to improve the energy efficiency. The
institute came up with an improved
design of VSBK in 1988 which had ahigher shaft height and provisions for apair of chimneys. About 50,000 VSBKs
were estimated to be operating in
China during 1996. Various attempts todisseminate VSBK technology outside
China started in the early 1990’s. It wasdemonstrated in several Asian countries
such as Nepal, Afghanistan, Pakistan and
Bangladesh. However, no appreciablesuccess was reported in the external domain to document factors of success.
VSBK in India was launched in 1995 by the Swiss Agency for Development &amp; Cooperation(SDC) as a project on introducing sustainable production systems for building materials. The
factors that have contributed towards its successful adoption in India was its suitability fordecentralised production systems and positioning as a means of improving the productquality thus ensuring higher returns of investment. Simple mechanisation was implemented
for unfired brick making, material handling, transportation and extrusion of unfired bricks.
Internal fuel in the form of coal, biomass and sawdust is added during the moulding of
unfired bricks – this creates highly favourable conditions for short cycle firing.
Thus within a span of 5 years (2000 – 2005) more than 100 VSBK’s were established in acommercial mode. The qualities of bricks were accepted in the market at a premium.
Most of the entrepreneurs were satisfied with the flexibility and performance of the kiln.
This was reiterated by the increasing investment in selective mechanisation and capacity
augmentation.
After the commercial success of VSBK in India as a viable alternative to traditional brickmaking with huge potential to energy and environment savings, VSBK technology was
reopened in Nepal. The programme is being implemented by Skat Consulting in association
with Development Alternatives and HMG, Nepal. Under this technical support programme,
two pilot kilns were constructed and successfully implemented by 2004. Initial operationachieved a 30% reduction in energy consumption and around 80% reduction in emission
parameters.

72 | Pre-Feasibility Studies for Implementation of Green Brick Production

Encouraged by positive results, HMG, Nepal banned the operation of movable chimney
BTK’s and has also initiated legal and administrative action to convert the existing polluting
brick kilns into energy efficient and less polluting technologies. A high level of awareness on
economics of VSBK business has also been created amongst brick producers.
Kiln description and working principle
VSBK has a vertical shaft of rectangular or square cross-section. The gap between the shaft
wall and outer kiln wall is filled with insulating materials – broken bricks and burnt coalash. The kiln works asa counter-current heat
Figure 49: Working principle of VSBK
exchanger, with heat
Chimneytransfer taking place
Corrugatedbetween the air moving
Tin Roof
up (continuous flow)
Lid / Cover
Loadingand bricks moving
Green Bricks
Loading
down(intermittent
Platform
Air Flows Upwards
movement).
Unfired
Loading
InsulationPre
bricks are loaded in
Ramp
Heating Fill
Zone
batches from the kiln
SpySpace forCentral Holes
Central
top. Bricks move down
Support Bars
FiringFiringZone
the shaft through brick
Zone
Soil &
Fired
pre-heating, firing and
RubbleBricksCooling
Infillcooling zones andZone
unloaded from bottom.
The combustion ofcoal (added along with Bricks Move
Unloading ofbricks at the top) takes Downwards
BricksBrick Trolley
Support Bars
place in the middle ofthe shaft. Combustion
air enters the shaft from bottom, gets preheated by hot fired bricks in the lower portion of the
shaft before reaching the combustion zone. Hot combustion gases preheat unfired bricks in
the upper portion of the shaft before exiting from the kiln through the shaft or chimney.
The brick setting in the kiln is kept on support bars at the bottom of the shaft. Unloading ofbricks is done from the bottom of the shaft using a trolley. The trolley is lifted (using a single
screw mechanism) till the iron beams placed on the trolley touches the bottom of the bricksetting and the weight of bricks is transferred onto the trolley. The freed support bars aretaken out. The trolley is then lowered by one batch (equivalent to 4 layers of bricks) – support
bars are again put in place through the holes provided in the brick setting for the purpose.
With slight downward movement, the weight of the brick setting is transferred to support
bars. The trolley (with one batch of fired bricks on it) is further lowered till it touches groundlevel and then pulled out of the kiln on a pair of rails provided for the purpose. Every 2 - 3hours, one batch of fired bricks is unloaded at bottom and a batch of fresh unfired bricks is
loaded at the top simultaneously. At any given time, there are typically 11 to 12 batches in
the kiln depending on the unfired brick quality.
Two chimneys located diagonally opposite to each other in the shaft remove flue gases fromthe kiln. A lid is also provided on the shaft top which is kept closed during normal operation.
Flue gases are directed to pass through chimneys thus not polluting the working area on

Pre-Feasibility Studies for Implementation of Green Brick Production | 73

the kiln top. The provision of shaft lid, better ventilation of the working area on kiln top andhigher and bigger chimneys are some of the highlights of VSBK kiln and its related process.
The heating cycle for the unfired bricks is raw material specific (pre-heating, vitrification andcooling down) and is normally completed within 24-30 hours. A batch of bricks is loaded
and unloaded every 2-3 hours, requiring round the clock operations and supervision. Thisrequires special skills and the firing operator needs to maintain a correct balance between:
EnergyControlled byamount of coalfeeding

Airflow
Controlled bystacking density anddamper position

Unloading speed
Controlled by theoperator

CASE STUDY

Brick sector in Bihar
Bihar has been demonstrated as a successful example in adoption of alternate technologies in the
brick sector. Besides the uptake of fly ash bricks in the state, the transition of existing FCBTK kilns
to zig zag kilns has also been making much headway. Infact, almost half (43%) of the existing kilns
have been converted to zig zag. This offers a very promising picture for the emissions reduction
targets for the state.
A mapping exercise of the brick kilns in Bihar was conducted based on which the following
data has emerged. Note that the map below merely identifies the location of the kilns . Further
investigation and zooming in will reveal the detailed numbers of the kilns around these clusters.
These have been mapped through ground verification, the details of which have been enlisted in
the subsequent Table
Figure 50: Location of brick kilns operating in Bihar as of year 2022

74 | Pre-Feasibility Studies for Implementation of Green Brick Production

Table 16: District wise classification of kilns operational in Bihar as of 2022
District wise - Technology classification
District wise - Technology
classification

FCBTK

uncertain

ZigZagGrand Total

Araria

23

2

83

108

Arwal

53

3

7

63

Aurangabad

174

16

62

252

Banka

3

4

3

10

Begusarai

28

8

119

155

Bhagalpur

56

6

95

157

Bhojpur

89

10

112

211

Buxar

72

10

67

149

Darbhanga

71

21

200

292

Gaya

314

47

132

493

Gopalganj

177

22

46

245

Jamui

79

17

66

162

Jehanabad

84

21

18

123

Kaimur (Bhabua)

103

8

61

172

Katihar

19

1

118

138

Khagaria

17

13

46

76

Kishanganj

14

8

168

190

Lakhisarai

23

5

29

57

Madhepura

37

16

69

122

Madhubani

120

11

178

309

Munger

16

1

30

47

Muzaffarpur

144

21

175

340

Nalanda

175

13

64

252

Nawada

214

8

54

276

Pashchim Champaran

160

4

83

247

Patna

151

109

240

500

Purba Champaran

321

14

91

426

Purnia

31

4

116

151

Rohtas

97

13

57

167

Saharsa

53

3

66

122

Samastipur

177

6

78

261

Saran

185

7

198

390

Sheikhpura

25

4

14

43

Sheohar

14

2

14

30

Sitamarhi

75

28

153

256

Siwan

193

15

96

304

Supaul

42

3

43

88

Vaishali

200

5

90

295

Grand Total

3829

509

3341

7679

Pre-Feasibility Studies for Implementation of Green Brick Production | 75

5.3 Comparative analysis of alternativetechnologies
It is apparent that most technologies being practised in India and neighbouring countries
with conditions similar to Assam will not be suitable for adoption. Based on the technology
briefed above, to decide the best suitable kiln type for Assam some basic criteria were
decided. These criteria were based on technical suitability and performance economics.
Thus the following criteria were assumed during the technology selection:i.

Production capacity
Considering the market and the socio-economic fabric of Assam it is well defined that all
and any type of brick production has to be of medium scale and not of very high capacity
unlike the brick production usually followed in the Indo Gangetic plains of Uttar Pradesh,
West Bengal, Punjab, Haryana and Bihar.

ii.

Fuel type
Any fuel can be used for brick firing except “non-renewable”. However, gas or high-speed
diesel availability is not feasible in Assam. Thus, the only fuels used for brick firing technologies
have to be only coal or waste biomass in pelletized form.

iii.

Product quality
The product quality is of very high concern in Assam and should necessarily fulfil the existing
market standards. Therefore, the bricks should be of uniform shape and size with acceptablestrength suitable for construction as per the local codes. In this respect, the feasibility ofusing compressed earth blocks may be explored depending upon the rainfall and humidity
conditions. While CEB is not recommended in areas of high rainfall due to the adverse effectof humidity on the comprehensive strength of bricks , it may however be used in areas with
low to medium humidity.

iv.

Investment capacity
With the Covid-19 conditions the investment capacity of entrepreneurs has reduced. In
Assam the brick consumption is restricted to a couple of areas and is not very high. Brick
activity cannot be taken up for extended seasons due to climatic conditions. Although
entrepreneurship initiatives are also picking up however under present conditions any
technologies should be of low to medium investment and not the high end one.

v.

Carbon market
Any technology to be adopted in Assam should be energy saving and less polluting. With
the savings in greenhouse gases, the technology should be able to mitigate climate change
thereby creating a possibility of earning carbon credits.

vi.

Feasibility of utilization of Industrial Hazardous and Other
Waste including Drilling mud, drill cuttings
Various types of industrial wastes are available in Assam. They range from boiler ash fromfoundry, steel re-rolling, agri-processing industry to even bentonite clays from the oil welldrilling industry. The boiler ash is an important additive that can be used for various types ofbrick making depending on the calorific value. If of low calorific value i.e. < 1000 KCal/kg thenit can be used for lime gypsum based bricks. If higher then it will be a good raw material for
addition as internal fuel replacing the coal.
Generally the oil well drilling mud has a composition of bentonite and other smectite richplastic clays. They also contain an appreciable amount of crude oils and other drilling fluids.

76 | Pre-Feasibility Studies for Implementation of Green Brick Production

These can be a good source of brick making clays. It is expected to consume much lessenergy and produce a high quality bricks due to the inherent plastic properties of the clayeysoil being used. However the amount of waste availability needs to be assessed through astudy along with the economics of production.
Table 17:Decision making matrix
Decision making matrix
Brick firing technologies
FCBTK

Zig Zag kiln
Forceddraught

Zig Zag kiln
Naturaldraught

Bench markfor Assam
context

Capacity of kiln

High

High

High

Medium-low

Type of fuelVariable

Fixed

Fixed

Coal/biomass

Fuel switch facility

Yes

No

No

No

Homogeneity of temperature

High

High

High

High

Energy requirement /kg brickHigh

Moderate

Moderate

Low
Low

Heat recovery for drying

Yes

Yes

Yes

High
Moderate

Criteria

Capable toproduceRoofing tiles

Yes

Yes

NA

Hollow bricks

Yes

Yes

Yes

Solid bricks

Yes

Yes

Yes

Floor tiles

Yes

Yes

NA

-

Very
-

Emissions to atmosphere

Moderate

Moderate

Moderate

Low

Workplace emissions

Moderate

Moderate

Moderate

Low

Possibility of fulfilling emission norms Moderate

High

High

High

Requirement of quality unfired
brick

Low

Low

Low

High

Product quality

Good

Good

Good

High

Monthly production

High

High

High

Moderate

Land requirement

High

High

High

Low

Ability to operate throughout the
No
year

No

No

Yes

Production losses

Low

Low

Low

Low

Investment

MediumMediumMediumLow - medium

Return on investment

MediumMediumMediumFast

Organisational requirements

High

High

High

High

Local capacities for construction

No

No

No

Yes

Availability of materials forconstruction

Yes

Yes

Yes

Yes

Experience of implementation

No

No

No

Yes

Valid PDD

No

No

No

Yes

Total positive points

7

10

10

Pre-Feasibility Studies for Implementation of Green Brick Production | 77

Brick firing technologies
Criteria

HoffmannDown
draught

Capacity of kiln

High

High

Variable

Medium-low

Type of fuelVariable

Variable

Fixed

Coal/biomass

Fuel switch facility

Yes

Yes

No

No

Homogeneity of temperature

High

High

High

High

Energy requirement /kg brick

Moderate

Moderate

Very low

Low - Very Low

Heat recovery for drying

Yes

Yes

Yes

High - Moderate

Roofing tiles

Yes

No

Yes

NA

Hollow bricks

Yes

Yes

Yes

Yes

Solid bricks

Yes

Yes

Yes

Yes

Floor tiles

Yes

No

Yes

NA

Emissions to atmosphere

Moderate

Moderate

Low

Low

Workplace emissions

Moderate

Moderate

Low

Low

Possibility of fulfilling emission
High
norms

Moderate

Very highHigh

Requirement of quality unfired
Low
brick

Low

High

High

Product quality

Good

Good

Good

High

Monthly production

High

High

Variable

Moderate

Land requirement

High

High

Low

Low

Ability to operate throughout
Yes
the year

Yes

Yes

Yes

Production losses

Low

Low

Low

Low

Investment

Very highMediumMediumLow - medium

Return on investment

MediumMediumMediumFast

Organisational requirements

High

High

High

High

Local
capacities
construction

No

No

No

Yes

Availability of materials forYes
construction

Yes

Yes

Yes

Experience of implementation No

No

No

Yes

Valid PDD

No

No

Yes

Yes

Total positive points

8

8

17

Capable toproducefor78 | Pre-Feasibility Studies for Implementation of Green Brick Production

VSBKBenchmark for
Assam context

Brick firing technologies
Criteria’s

Internal

Fly ash

CEB

fuel

block

Bench mark for
Assam context

Capacity of kiln

High

Low

Low

Medium-low

Type of fuelVariable

Nil

Nil

Coal/biomass

Fuel switch facility

Yes

NA

NA

No

Homogeneity of temperature

High

NA

NA

High

Energy requirement /kg brick

Low

Very low

Very low

Low - Very Low

Heat recovery for drying

Yes

NA

NA

High - Moderate

Roofing tiles

Yes

Yes

Yes

NA

Capable to

Hollow bricks

Yes

Yes

Yes

Yes

produce

Solid bricks

Yes

Yes

Yes

Yes

Floor tiles

Yes

Yes

Yes

NA

Emissions to atmosphere

Moderate

Nil

Nil

Low

Workplace emissions

Moderate

Nil

Nil

Low

Possibility of fulfilling emission norms

High

Very highVery highHigh

Requirement of quality unfired brick

Low

NA

NA

High

Product quality

Good

Good

Good

High

Monthly production

High

Low

Low

Moderate

Land requirement

High

Very low

Very low

Low

Ability to operate throughout the year

Yes

Yes

Yes

Yes

Production losses

Low

Low

Low

Low

Investment

Very low

Very low

Low

Low - medium

Return on investment

Very highMediumVery highFast

Organisational requirements

High

Low

Low

Low

Availability of replicas

Difficult

Difficult

Easy

Easy

Yes

Yes

Yes

Yes

Experience of implementation

No

No

Yes

Yes

Valid PDD

No

No

Yes

Yes

Total positive points

12

13

13

Availability of materials forconstruction

Pre-Feasibility Studies for Implementation of Green Brick Production | 79

5.4 Scenario Building for GHG Emissions
Furthering our findings from the above study on brick kiln GHG emissions, computational
analysis was undertaken to arrive at a realistic projection of emissions under different
scenarios. The same has been enumerated and mapped in Figure 33. An analysis of findings
from the scenario cases is presented in the summary section below.
Scenario 01: The following projection is computed using a cumulative compound
annual growth rate (CAGR) of 7.3% which is the annual average of the Indian
construction industry and business as usual i.e. no replacement of FCBTK byalternate technology, the total GHG emission from brick kilns only will reacharound 46.87 tons per year by 2030 and 193.60 tons per year by 2050.
Figure 51 : Graph depicting projected estimate of GHG emission under scenario 1
i.e. if present brick manufacturing continues using FCBTK.
Scenario 1: If present manufacturing continues using FCBTKScenario 02: The following projection shows the comparative GHG emissions in lakh tonsof the different technologies in comparison to the existing brick technology of
FCBTK kiln. It can be seen from the graph below that a 100 percent conversion
to compressed earth block making would lead to the maximum reduction of
GHG emissions and is the most ideal technology.
Figure 52: Graph depicting projected estimate of GHG emission under scenario 2 i.e. if
present brick manufacturing is completely replaced by CEB
Scenario 2 : Complete conversion to CEB

80 | Pre-Feasibility Studies for Implementation of Green Brick Production

Scenario 03 : The following projection shows the comparative GHG emissions of partial
conversion of FCBTK kiln technologies with zig zag kilns.It can be seen fromthe graph below that a 100 percent conversion to zig zag kiln would be themost ideal for reducing GHG emissions as compared to FCBTK which iscurrently used.
Figure 53 : Graph depicting projected estimate of GHG emission under scenario 3 i.e. if
present brick manufacturing through FCBTK undergoes gradual and partial conversion
with zig zag kiln.
Scenario 3 : Variable conversion to zig zag kiln

Scenario 04: The following projection shows the comparative GHG emissions of partial
conversion of FCBTK kiln technologies with VSBK .It can be seen from thegraph below that a 100 percent conversion to VSBK would be the most ideal
for reducing GHG emissions as compared to FCBTK which is currently used.
Figure 54 : Graph depicting projected estimate of GHG emission under scenario 4 i.e. if
present brick manufacturing through FCBTK undergoes gradual and partial conversion
with VSBK.
Scenario 4 : Variable conversion to VSBK kiln

Pre-Feasibility Studies for Implementation of Green Brick Production | 81

Scenario 05: The following projection shows the comparative GHG emissions of partial
conversion of FCBTK kiln technologies Compressed earth blocks as a bricktechnology.It can be seen from the graph below that a 100 percent conversion
to CEB would be the most ideal for reducing substantially the GHG emissions
as compared to FCBTK which is currently used.
Figure 54: Graph depicting projected estimate of GHG emission under scenario 5 i.e. if
present brick manufacturing through FCBTK undergoes gradual and partial conversion
with CEB.
Scenario 5 : Variable conversion with CEB

5.5 SUMMARY
It is evident from the comparative analysis of alternative technologies against conventional
practices that the environmental impact and economic feasibility of certain technologies
is more suited for Assam. The criteria setting and decision making matrix provides a clear
path for transforming the brick sector in favour of VSBK and zigzag as the kiln type, andcompressed earth block as brick type, while internal fuel or coal and waste biomass inpelletised form may be used to for optimisation of the firing process.
This is substantiated through the following learnings of the research: VSBK scores the highest
positive points in brick firing technologies (17) while Zig Zag kiln comes in second in both,natural and forced draught with a score of 10. In terms of brick type, both CEB and flyashscore similar positive points (10).
It can also be seen from the scenarios presented for GHG emissions reduction that completely
replacing FCBTKs with a zig zag kilns can lead to a reduction of almost 20% in GHG emissions
annually, compared to almost 40% reduction with complete conversion to VSBK. However,
the maximum reduction in GHG emissions can be seen in conversion from FCBTK to CEB
making with potential 90% savings. Hence, it can be seen that out of all the options, CEB
offers the maximum decarbonising and emission reduction potential.
With respect to their applicability to the size and scale of enterprises, all these proposed
alternatives are most suited for medium to small scale brick producing enterprises. While
the adoption of these new technologies requires consistent training and capacity building,they score well above conventional technologies with respect to energy consumption,
environmental emissions and return on investment. In comparison to FCBTK on the initialinvestment required, VSBK has the ability to produce consistent quality bricks getting higher
returns which is a more sustainable trade off in the long term, both from the prospect offinancial recovery and for achieving higher productivity.

82 | Pre-Feasibility Studies for Implementation of Green Brick Production

The complete transformation of the brick making sector needs to consider strategies for longterm, medium-term and short-term action considering the findings from the comparative
analysis based on the decision-making matrix as well as the scenario building graphs for
GHG emission reduction potential. The policy pathways for this transition must criticallyconsider all social, environmental and economic parameters to ensure the balancing of bothdemand and supply side factors and the readiness of the enterprises as well as the markets.
In order to ensure easy adaptability of these technologies, business plans for the selected
technologies have been given in Annex 4, 5 and 6. These have been formulated after thoroughground research into financial and technical research to arrive at replicable business models
for small and medium enterprises and entrepreneurs.

5.6 Enabling Access to Finance for Transitioning toGreen Brick Production
Transitioning to greener brick production from the current FCBTK technologies being
currently practiced in Assam requires a major shift in the technologies, infrastructure andskills of the brick manufacturers, which necessitates availability of finance to enable thetransition since most brick production in the state is presently carried out by micro and small
enterprises.
Considering the substantial size of the MSME sector in India and the numerous challenges
faced by such entrepreneurs, many government schemes and programmes have been
initiated to support them. Such initiatives seek to address the various needs of MSMEs
including improving access to finance and credit, providing infrastructure support,
supporting technology upgradation and green certification, marketing and web services, aswell as skill development and training.
To promote entrepreneurship in the brick production sector, several government schemes
promoting local manufacturing activities can be leveraged to facilitate finance for both
capital and operational expenses. Specific schemes are also targeted towards women
entrepreneurs and vulnerable groups. Some possible opportunities for enabling access tofinance as per their specific needs for transitioning to greener brick production in Assamhave been listed below:

5.6.1 PRADHAN MANTRI EMPLOYMENT GENERATION PROGRAMME(PMEGP)
This initiative aims to generate employment opportunities in rural as well as urban areasof the country through enhancing access to finance for new self-employment ventures/projects/micro enterprises with collateral free loans up to INR 10 lakhs while requirement
for collateral guarantee for loans above INR 10 lakhs may be supported by Credit Guarantee
Trust for Micro and Small Enterprises (CGTMSE). The scheme is implemented by Khadi and
Village Industries Commission (KVIC) as the nodal agency at the national level and throughstate bodies, District Industries Centres (DICs) and banks at the state level.

5.6.2 PRADHAN MANTRI MUDRA YOJANA (PMMY) | MICRO UNITSDEVELOPMENT & REFINANCE AGENCY LTD. (MUDRA)MUDRA loans are extended to eligible applicants under the Pradhan Mantri Mudra Yojana(PMMY). Micro Units Development and Refinance Agency Ltd. (MUDRA) is a refinance agency
which extends loans to Commercial Banks, Regional Rural Banks (RRBs), Small FinanceBanks, Micro Finance institutions (MFIs) and Non-banking finance corporations (NBFCs)
which then further provide loans to individuals. Within MUDRA there are three kinds of

Pre-Feasibility Studies for Implementation of Green Brick Production | 83

loans – Shishu, Kishore and Tarun to signify the stage of growth and funding needs of thebeneficiary micro unit or entrepreneur.
•

Shishu: loans up to INR 50,000•

Kishor: loans above Rs.50,000 and up to Rs.5 lakh•

Tarun: loans above Rs.5 lakh and up to Rs.10 lakh

5.6.3 STAND-UP INDIAThe Stand-Up India scheme was launched to support SC/ST entrepreneurs and women
entrepreneurs in setting up enterprises, & obtaining loans and other support needed fromtime to time for succeeding in business. Composite loans (inclusive of term loan and working
capital) are provided between Rs.10 lakh and up to Rs.100 lakh representing up to 75% of the
project cost.

5.6.4 MAHILA UDYAM NIDHI YOJNA
Under Mahila Udyam Nidhi Yojana (MUNY), women entrepreneurs may obtain loans frompublic and private sector banks to undertake small/micro business for upto 25% of project
cost, with maximum project cost limited to INR 10 lakhs.

5.6.5 UDYAM NIDHI YOJNA
Under the Udyam Nidhi Yojana (UDY), National Scheduled Castes Finance And Development
Corporation (NSFDC) offers loans to eligible Scheduled Caste persons to undertake small/micro business. Loans are offered under this scheme through Cooperative Societies andCooperative Banks (Channelling Agencies) to pursue small/micro operations that meet theneeds of the recipients with loans limited to 90% of the project cost.

5.6.6 CGTMSE | Credit Guarantee Fund Trust for Micro and SmallEnterprises
The Ministry of Micro, Small and Medium Enterprises (MoMSME), Government of India(GOI) and Small Industries Development Bank of India (SIDBI) set up the Credit Guarantee
Fund Trust for Micro and Small Enterprises (CGTMSE) to strengthen collateral-free credit.
Additionally, to enable the possibility of lending composite credit to the borrowers so thatthey can get both a term loan and working capital from a single source. Under this initiative,
new and existing Micro and Small Enterprises engaged in manufacturing and services canavail loans up to INR 2 crores and retail trade up to INR 1 crore.

5.6.7 Micro and Small Enterprises- Cluster Development Programme(MSE-CDP)
This scheme was launched to support the sustainability and growth of MSMEs by addressing
common issues such as improvement of technology, skills & quality, market access, to create/
upgrade infrastructural facilities in the new/existing industrial areas/clusters of MSEs, to set
up common facility centres (for testing, training, raw material depot, effluent treatment,complementing production processes, etc.), and promotion of green & sustainable
manufacturing technology for the clusters.

84 | Pre-Feasibility Studies for Implementation of Green Brick Production

5.6.8 Credit Linked Capital Subsidy for Technology Upgradation(CLCS-TU)
The Credit Linked Capital Subsidy Scheme is a scheme run by the Ministry of Small Scale
Industries (SSI) to help Small Scale Industries upgrade their production equipment (plantand machinery) by giving an upfront capital incentive. The Small Industries Development
Bank of India (SIDBI) and the National Bank for Agriculture and Rural Development(NABARD), and nine Public Sector Banks/ Government Agencies act as the Nodal Agencies
for the implementation of this scheme.

5.6.9 Sustainable Finance Scheme
The Small Industries Development Bank of India (SIDBI) launched the Sustainable Finance
Scheme, to fund sustainable development projects that contribute to energy efficiency
and cleaner manufacturing but are not covered by international or bilateral lines of credit.
Suitable assistance is provided using term loans or working capital loans to cover all
sustainable development projects, including renewable energy projects, Bureau of Energy
Efficiency (BEE) star ratings, green micro-finance, green buildings, and eco-friendly labelling,
among others.

5.6.10 10. Lean Manufacturing Competitiveness Scheme (LMCS)
Under this scheme, MSMEs are assisted in reducing their manufacturing costs, throughpersonnel management, better space utilization, scientific inventory management,
improved process flows, reduced engineering time and so on with the application of LM(lean manufacturing) techniques. The Scheme is basically a business initiative to reduce“waste” in manufacturing. Existing MSMEs are required to form a Mini Cluster (6-10 units)(These units would work with the assigned LMC to implement the specific LM techniques).
Mini clusters (MCs) are required to formalize their association by forming a SPV.

5.6.11 ZED Certification Scheme - Zero Defect Zero EffectThis scheme was launched to raise MSMEs’ knowledge of ZED (zero defect, zero effect)
manufacturing, push them to assess their businesses for ZED, and provide them with support.
Following a ZED assessment, MSMEs can significantly cut waste, enhance productivity,
expand their market etc. All the Udyog Aadhar Memorandum (UAM) registered manufacturing
MSMEs are eligible to apply for ZED registration. A self-declaration / undertaking is to begiven by the MSME willing to obtain the ZED certification.
The certification helps in providing a competitive edge in public procurement because ofcertificate of excellence and national recognition. Incentives under the scheme include
reimbursement of 80% for Micro, 60 % for Small and 50% for Medium for ZED Certification oflevel 2 and 3 (silver, gold), 80% of the cost of consultancy reimbursed by Ministry of MSME,
subject to an upper ceiling fixed for level 4 and 5 (Diamond and Platinum)

Pre-Feasibility Studies for Implementation of Green Brick Production | 85

86 | Pre-Feasibility Studies for Implementation of Green Brick Production

6
6. Conclusion,
recommendations
and way forward

Pre-Feasibility Studies for Implementation of Green Brick Production | 87

This chapter suggests recommendations and the way forward for greening the brick sector
in Assam based on the key findings of the pre-feasibility study. These recommendations
are grounded on secondary research and field studies conducted by the team in the main
centres of brick production in Assam. Based on the discussions and studies conducted at
ground level with the brick producers, local entrepreneurs and government bodies in Assam,
limitations were identified. The recommendations and way forward being proposed are in
keeping with the local context and practical challenges faced by the producers and somekey areas of intervention have been identified for sustainably developing the brick sector in
Assam. These are enumerated in the subsequent sections.

6.1 Approach for sectoral transformation
It has emerged from this study that in order to operate a successful brick business in
Assam, the three most essential criteria to be fulfilled are adequate capital, efficiententrepreneurship/management approach and a sustained market demand for the product.
The same criteria extends to introduction of any new production methodology, system or
technique in the state.
However, none of this can take place without an enabling environment, promoted by the
key stakeholders i.e the brick producers on one hand and policy makers on the other. While
the former is driven by profitability, the latter looks at all-round sustainability. Both theirintentions need to be met in order to sustain growth and greening of the brick sector.
Hence four criterias emerge, which, once fulfilled, can ensure profitability for the
brick producing enterprise. The same holds true for introducing any new techniques,
methodologies or processes. For successful acceptance and adaptation of technologies
and methodologies, a crucial role needs to be played by key players of brick producers andpolicy makers. While the brick producers’ sole intent is profitability, policy makers look atlong term sustainability.
In this respect, it must be noted that while introducing any new methodology, some resistanceis to be expected and even prepared for. A more appropriate approach in such a scenario
would be to target local needs, aspirations, socio-economic and behavioural change in all
stakeholders. This involves a paradigm shift in mindsets which can be achieved throughextensive awareness campaigns, widespread demonstration of technologies, training,
capacity building and sustained technology support to the entrepreneurs, workforce andgovernment agencies. Such an approach ensures a conducive environment for conducting
pilot or demonstration studies since the stakeholders would be better equipped to receive
new technology and inputs.
With respect to the technology and process, brickmaking is still largely a manual and labour
intensive activity in Assam, associated with long working hours and occupational hazards. It
is however envisaged that mechanised brick production will be introduced in Assam in a big
way to cater to the challenges faced by entrepreneurs from skilled moulders. In fact the local
soil is also most appropriate for mechanised brick making. Thus, attempts must be made tousher in various green and mechanised brick production at an appropriate time.
Other than these, systemic change in the technology and brick production process as awhole is an equally crucial determinant for any new initiative to sustain. Experiences in otherstates of the country indicate that in the brick sector any technology transfers should not only
include improved firing methods and technologies but incremental changes in the entire
production system. It should not only be seen as a short time investment of commercial
approach but a long term development strategy demonstrating success, thereby creating
sustainable demand. Simultaneously supply services should be matured enough to meetthe demand in commercial terms. Thus the project should and will possess the skills of

88 | Pre-Feasibility Studies for Implementation of Green Brick Production

timely intervention and appropriate withdrawal from the developmental approach to amore commercial environment.
With the above in mind it is imperative that the initiatives and interest created be sustained
through a demonstration initiative. Given that demand has already been created in the mindsof entrepreneurs at Bongaigaon and Nagaon, it must be acted upon by demonstration of thepilot kiln and strengthened through favourable policy directives. This initiative needs to becarefully nurtured and developed over the next couple of years.
Coming to the management of brick producing enterprises and businesses, efficiency andcompetency is key. Unfortunately this aspect is not given due importance in the existing units
since it is presently associated with relatively simple technology ,lacking a robust businessstrategy to withstand any external shocks. It must be emphasised that unlike a standard
commercial business practice with its contingency plans in place, a brick production unit
in remote areas of Assam is ill-equipped to withstand comparable setbacks by virtue of its
location, access to technology, knowledge or entrepreneurship environment.
Management, in this regard, entails planning, organising, staffing and controlling the
production such that the bricks can be produced within budget and sold profitably. This isachieved by ensuring good financial , logistics , human resource management, production
process management etc. as elaborated below :•Production process management■
Adequate and timely supplies of raw material■
Maintenance of equipment■
Quality control of raw material, process and finished product■
Smooth flow of production•

Financial management■
Adequate financial arrangements for wages and general purchases■
Good bookkeeping system•

Human resource management■
Suitable recruitment and training of skilled personnel■
Specific tasks and roles for each staff■
Periodic skill upgradation■
Good human behaviour•

Conducive work environment equipped with sanitary facilities for workers, ensuring
their safety and comfort and in accordance with building codes.

In addition to the above, good management also extends to efficiently managing theworkforce, its morale and participation in the process, especially since the current practices
are dependent on labour productivity. To achieve this, an equitable business strategy whichlinks and redistributes the enterprise’s surplus profits with the productivity and performanceof the workforce would motivate the workforce, especially in the case of Assam.

6.2 Recommendations and way forward
Based on the findings, conclusions and inferences drawn from this study, major areas ofintervention have been identified, both for the short term and subsequently for the longterm. Once addressed, it shall help resolve the bottlenecks and challenges faced in greening
the brick sector in Assam. The recommendations proposed in this respect are essentiallyhinged upon technical improvement and data collection to further research in the short term
while institutional, social, structural and systemic transformation is proposed for the longterm approach. These are explained in detail below:

Pre-Feasibility Studies for Implementation of Green Brick Production | 89

6.2.1 Recommendations for mapping and data collection:
In order to address the existing data gaps in the brick making sectors in the state, it isessential to establish robust data collection and management mechanisms to ensure readyavailability of information on the production and consumption trends as well as the socioenvironmental impacts of the same. As a first step, the following activities are proposed to geta holistic overview of the current status of the industry with accurate and verified numbers of
the kilns and the quantification of its impacts.

i) GIS based mapping of brick kilns
Till date, no reliable information exists either with the brick kiln association or Governmentof Assam or even with the State Pollution Control Board of Assam. According to Pollution
Control Board (PCB), Assam there were 731 brick kilns across the State till December 2012.
In addition, the Honourable Minister of Environment and Forest has informed the State
assembly that as of 2019-2020 there are 669 brick manufacturing kilns in the state as perreports collected from divisional forest offices. It is hard to believe that while the demand for
housing and infrastructure is increasing over the years, in a 7-year period the number of brickkilns has been reduced by 62.
Thus, it is of utmost importance to identify and map the exact number of brick kilns
functioning in the state. This can be done easily through the GeoAI tool which gives fairly
accurate data and can be further verified by ground truthing exercises to a limited variance.

ii) Resource mapping of raw materials for brick kilns
The major building material in Assam is clay bricks. Presently only agricultural topsoil isbeing used for brick making. It has been estimated in Assam Tribune that in 2021 more than
1,000 hectares of prime agricultural land are being lost annually to accommodate the brickmaking industry only in and around Dhubri district.
Therefore, it is recommended to carry out a primary and secondary resource mapping
study in Assam to identify the different raw materials available for making alternate building
materials which are low carbon and eco friendly. Based on the mapping, a zoning of brickkilns can be planned.

iii) GHG Inventorization of brick kilns in AssamNo data exists till date on the carbon emission load in Assam from brick kilns. An immediatestudy needs to be undertaken to define the GHG inventorisation of brick kilns in Assamand the industrial sector. This will help in estimating the intensity of emissions and takeappropriate measures for reducing the same.

6.2.2 Recommendations for technological improvement :The mainstreaming and popular uptake of the alternative technologies recommended inthis report requires visibility and demonstration of such technologies to build trust andconfidence of the brick manufacturers. For this, pilot demonstration and capacity building
towards the same are suggested as described below.
Annexure 7 gives further details on the implementation of such measures in the form of a
Detailed Proposal on ‘Greening of the Brick Industry in Assam - Proposal for introducing
energy efficient, low carbon burnt brick production technologies’.

90 | Pre-Feasibility Studies for Implementation of Green Brick Production

i) Pilot demonstration of alternate technologies
To undertake any pilot demonstration activity, involvement and ownership of entrepreneurs
and beneficiaries are an absolute must. Based on discussion and agreement on the typeand choice of technologies, there should be a pilot demonstration kiln constructed in eachand every feasible district. The choice of technologies should depend upon the criteria
and decision making matrix developed in previous sections (Table 15) . These will act asa confidence building measure amongst brick kiln owners, enabling them to shift towards
cleaner brick production systems and processes.
With respect to the feasibility of using piped natural gas as fuel in accordance with Government
notification vide. G.D.R 143(E) dated 22 February 2022 , the State Pollution Control Board of
Assam must enforce and implement these notifications urgentlyii) Technology transfer, Training and capacity building of stakeholders
and awareness generation
To assist local brick manufacturers to achieve self-sustainability, interventions in technology
upgradation through training and capacity building during any technology transfer are ofutmost importance. The TARA team had accompanied ACCMS in two awareness workshops
at Bongaigaon and Nagaon. It is to be noted that the majority of the entrepreneurs were
unaware of alternative technologies and materials like VSBK kilns, Zig Zag kilns, compressed
earth block, fly ash. Even the possibility of using internal fuel was an eye-opener. Thus,
awareness workshops are suggested to be carried out in each district at regular intervals toenable informed decision making.

6.2.3 Recommendations for structural transformation
In addition to the immediate and short term measures listed above, a long term approachalso needs to be developed and implemented, in order to effect a systemic transformationof the Assam brick sector . This may be achieved through a sustained programme focussing
on Greening the Brick Sector in Assam. Major strategies to be adopted throughout this longterm programme are listed below:i) Policy and institutional support
It is suggested to institutionalise a “Clean Brick Sector Programme”. This can be made possible
through a close collaboration with the concerned governmental institutions at all the stagesof project implementation. They must be consulted as and when required and must be
supported in fulfilling their roles and responsibilities in relation to sustainable development
and livelihoods. Support and technical assistance must be provided to government
agencies to develop and enforce policies and standards such as performance monitoringmechanisms,, technical support to co-develop a sound brick sector policy, setting suitableemission standards and evaluation or decision making criteria and formulating associatedrules, regulations and guidelines for facilitating effective technology dissemination.

ii) Business and financial support
A demand-driven commercial and business development approach must be developed fortechnology transfer in any project/programme/pilot. It shall not advocate for any specifictechnologies but rather work on creating a demand for the same in the market throughsuccessful demonstrations.

Pre-Feasibility Studies for Implementation of Green Brick Production | 91iii) Implementation support through ancillary service providers
Local suppliers, manufacturers, ancillary enterprises and service providers must be supported
and the successful implementation of the programme must be facilitated through a robust
economic model and network which benefits all stakeholders equitably. Such a support
network of suppliers and support service providers will help in anchoring the technologies
at a local level, thereby enabling them to “sell” professional services at competitive market
rates.

iv) Contextualisation of technology
The introduction of new technologies such as VSBK, internal fuel, fly ash bricks, compressed
earth blocks or even AAC blocks must be well anchored within the local socio-politicaleconomic and geographical context of Assam. This is needed to create ownership and also
to address the dissemination potentials. Relevant public/private sector agencies need to
be included in the project process in order to guarantee their support and facilitation to theprogramme.

v) Incubation centres/Pilot projects in every district
To sustain the efficacy and adoption of pilot demonstrations, a startup/incubation approach
may be adopted to prepare the foundation/basework for the first phase of the long term
development process. This will test the suitability and feasibility of selected retrofitting
initiatives or clean brick technologies with local entrepreneurs in each district of Assam. Thisis envisaged with an aim to initiate and encourage technology adoption across the district
through successful pilot demonstration.

vi) Periodic training and capacity building
A long term capacity building sub-programme must be developed for different levels of
stakeholders. This must be sustained through periodic revisions and upgraded based onfield response. Assistance in building a favourable environment may be provided by external
experts , however the main responsibility or anchors/pivots must be with local partners. The
aim is to engage local organisations or capable individuals to deliver support services asmuch as possible.

vii) Human capital development and knowledge management
The products, processes, technologies and economic models created through theprogramme should be documented and made accessible in a user-friendly way. Different
media of dissemination may then be explored based on the target audiences and their accessand limitations. Some of these may be in the form of videos, brochures, leaflets, manuals,
books, technical notes and documents, project websites. These shall be customised in both,national and international vernacular languages for easy understanding.

viii) Social development and occupational safety
Any green initiative must also be ‘responsible’ and conscious of its impact on human healthand wellbeing . In this respect, occupational safety and health issues of workers in the brickmaking sector should be continuously monitored for safe working processes and use of
personal protective measures. Awareness and training sessions on safety and health should
be conducted in greater detail and dovetailed with existing initiatives of the government orexternal agencies. This will inform workers to take necessary precautions while undertaking
tasks like coal breaking, coal crushing, pug mill operation, brick moulding process, head load
and transportation of bricks, particularly in the firing zone.

92 | Pre-Feasibility Studies for Implementation of Green Brick Productionix) Social responsibility
Last but not the least, any change in technology ,process, or means of production warrants
an equivalent shift in social structures and entrepreneurs being the risk takers and change
makers directly and indirectly influence these social changes. They must therefore
be sensitised about their role in influencing education and learning and their social
responsibility towards their society. In this respect, they themselves must be coached on thebenefits of non-formal learning programmes and child education for the children of workers,
who, due to lack of knowledge, end up working in kilns at a risk to their lives. A sensitisation
programme/ initiative may be taken up throughout the state. This will further motivate thebrick makers/workers once they realise the long term benefits of education for their family
members and future generations.
Hence, a holistic programme for greening the brick sector is suggested , which addresses
the economics, policy, and social challenges of the brick producers and workers througha systems approach. This multi level, multi stakeholder approach when implemented at asustained pace over a period of time is bound to change the business as usual approach andhelp develop sustainable materials and sustainable livelihood.

Pre-Feasibility Studies for Implementation of Green Brick Production | 93

94 | Pre-Feasibility Studies for Implementation of Green Brick Production

7
7. ANNEXURES

Pre-Feasibility Studies for Implementation of Green Brick Production | 95

ANNEXURE 1 - Baseline Assessment Framework
1.

Socio-Ecological Profile of State
1.1 Climate and topography of the statea. General weather conditionb. Climatic conditionc. Duration of rainy seasonsd. Season related average humidity
e. General topography of kiln cluster (if any)
1.2 Socio economic features of the statea. Total population of stateb. Per capita income of the people
c. Major economic activities of the people
d. Literacy rate of people

2.

Resource Availability
2.1 Soil mapping suitable for clay brick production
2.2 Alternate Material Availability

3.

Overview of Brick Industry
3.1 Structure of Brick Industry in Assama. Current and projected brick production and consumption trends in the stateb. Who produces the brick, the private sector or the government sector?
c. Scale of brick industry (small, medium, large), business environment of thebrick producers/industry in
d. Uses of fired brick in construction sector
e. Most common brick size (in mm) - length, width, heightf. During what time of the year are bricks produced?
g. Other types of bricks currently used for walling construction and acceptanceamongst masons and house owners (eg. hollow bricks, concrete blocks, etc.)
3.2 Technologies available and being practiced
a. Soil testing methods
b. Soil mining and ageing methodsc. Brick forming (moulding) methods
d. Brick drying methods
e. Brick firing technologies (which are available, which are most used)
f. Minimum annual brick production rate from most commonly used firing
technology mentioned above
g. What kind of mechanization (e.g. excavators, extruders, pug mills, convey
belts etc. are used to produce fired bricks?
h. Overall brick firing history of the state in general, detailed information aboutbrick making history of the hotspot study areas.
i. Brick making contracting methods, if any (e.g. mining, moulding andtransporting to the kiln) (kiln loading and unloading)j. Unfired brick transporting system (e.g. wheelbarrows, convey belts, manualtransportation etc.)
3.3 Understanding the fuel and material value chain
a. Types of fuel used for firing
b. Availability of coal and it’s uninterrupted supply

96 | Pre-Feasibility Studies for Implementation of Green Brick Production

c.
d.
e.
4.

Origin of coal
Sources of soil used in brick production
Sources of any other raw materials used in brick production

Operational Aspects of Brick Production
4.1 Energy and environmenta. Major pollutants that are emitted by brick kilns
b. GHG emission impact
c. Impact of brick kilns upon surrounding vegetation and the soil fertility
4.2 Social and labour
a. Major labour issues related to brick industries
b. Child labourc. Average number of workers working per brick kiln
d. Wage rate of workers
e. Average working hours per day
f. Employment ratio of men and womeng. Workplace facilities such as school, canteen, toilet, drinking water, housingetc.
h. Originality of workers (migration)i. Literacy status of workers
j. Labour law applicable to brick industries
k. Existing working condition standards
l. General skill requirements for industries
m. How workers are trainedn. Assessment of occupational safety and health measures

5.

Financial Summary of Brick Production
5.1 Economics of brick production
a. Average construction cost of kiln
b. Running cost of kilnc. Average cost of unfired bricks (per thousand)d. Cost of fuel commonly used in brick industries (per ton)e. Wages of firemen / fire master (per month, or thousand bricks)
f. Cost of fired bricks (per thousand bricks)
g. Selling price of fired bricks (per thousand)h. Taxes to be paid by brick industries (annually or per thousand bricks)
i. Availability of financial supports from government and banks (if any)
5.2 Profit and loss situation of brick producers
a. Return on investment (ROI)
b. Payback periodc. Fixed investment

6.

Regulatory Landscape of Brick Production
6.1 Environmental concerns of people, government and other stakeholders
a. Environmental standards set by government for brick kilns
b. Standards set by government for the quality of coalc. Environmental monitoring of the kiln
d. Public pressure upon brick kiln owners related with environmental concerns
e. Environment related and active NGOs
6.2 Licensing Process
a. Current licensing process for establishing brick industry
Pre-Feasibility Studies for Implementation of Green Brick Production | 97

b.
c.
d.

Existing rules and regulations
Authorities involved in licensing and their responsibilities & duties
Challenges in current process

6.3 Other factors
a. Political issues and significant actors related to brick industries, if any
b. Non-governmental organizations involved in brick sector and their tasks (inenvironmental monitoring, Institution involved in brick, coal and soil testing)c. Corruption level, specially related to government administration and brickindustry

ANNEXURE 2 - Impact Assessment Matrix
For Assessment of Suitability of Proposed Technologies for Brick Production
1. Technical suitability•

Possibility for reduction in energy/liquid fuel/electricity•

Possibility to reuse waste heat•

Weather resistance of bricks•

Compressive strength, tolerance, water absorption, efflorescence test of bricks•

Homogeneity in brick quality for different kiln technologies•

Brick materials suitability for kiln technologies•

Capacity v/s market comparison for different kiln technologies•

Capacity utilisation•

Design life comparison of different kiln technologies•

Flexibility in production capacity and operability throughout the year•

Space requirement for different types of kilns•

Product quality comparison for different firing process•

Requirement of additional infrastructure for alternative kilns e.g., conveyor/lift (andelectricity) for lifting of bricks to the top in VSBK•

Suitability of kiln for any type of brick/tile/block production – diverse product portfolio

2. Financial Sustainability•

Reduction in cost of fuel•Profits due to fuel savings and quality improvements.

•

Capital investment required for alternative measures•

Contribution to local economy•

Time frame for ROI•

Cost-Benefit analysis•

Financial instruments tailored for the sector•

Financial knowledge of entrepreneurs in the brick sector•

Tax compliance of the sector as majority of the transactions takes place in cash

3. Environmental indicators•

CO2 and other gaseous pollutants•

Black carbon emission

98 | Pre-Feasibility Studies for Implementation of Green Brick Production•Suspended particulate matter formation•

Annual coal savings•

Alternative material source sustainability•

Waste generation comparison by the use of alternative material•

Extent of deforestation, top soil extraction, water consumption, fossil fuel extraction,and gas exhaustion avoided by the use of alternative materials and technologies•

Impact on agricultural soil•

Impact of de-silting and clay mining

4. Social indicators•

Employment generation•

Women employment generation•

Working condition of site workers•

Comparison of labour requirements for different kiln technologies•

Additional skill and training requirement for effective implementation of alternativetechnologies and methods of brick production.

•

Impact on health of residents in close proximity to brick production•

Health impact – pulmonary/vision disorders in site workers•

Impact on food security•

Casualties related to brick sector pollution

Pre-Feasibility Studies for Implementation of Green Brick Production | 99

ANNEXURE 3 – Characteristics of coal usage
CALORIFIC VALUE OF ASSAM MATERIALSSL.NO SAMPLE NAME

MATERIAL

Calorific
Value(kcal/kg)

AshContent(%)

Loss of
Ignition(%)

1

BAPUNG(MEGHALAYA)

Coal

8251.756

94

2

LATUNG BAI MEGHALAYA

Coal

7283.1210

90

3

BAPUN-MEGHALAYA(BRICKS)

Coal

3300.61

57

43

4

MGNHUAYA-BAPUN

Coal

2782.03

66

34

5

MBI-CHEPTI

Coal

7468.46

11

89

6

ASSAM- GARAMPANI

Coal

3391.00

55

45

7

SMB-NAGALAND

Coal

7203.69

21

79

8

ASSAM- MNU

Coal5826.88

28

72

9

HBI-CHEPTI

Coal

6764.53

7

93

10

JPB-CHANDRAPUR

Coal7097.78

18

82

11

SRB-GUWAHATI

Coal7680.27

7

93

12

BBS-SINGHMARI

Coal

7907.6111

89

100 | Pre-Feasibility Studies for Implementation of Green Brick Production

ANNEXURE 4 – Compressed Earth Block
Technology Business Plan Details

Detailed Project ReportCompressed Earth
Block Technology

JUNE 16, 2022
Technology and Action for Rural Advancement
B-32 TARA Crescent, Qutab Institutional Area
New Delhi - 110016
Pre-Feasibility Studies for Implementation of Green Brick Production | 101

1. Introduction
Earth as a construction material has been used for thousands of years by civilizations allover the world. It is the most abundant building material known and available in majority of
the locations across the world. The traditional soil construction methods followed in many
countries are cob (mixture of straw, gravel and clay), wattle and daub (coarse basket work oftwigs woven between upright poles and plastered with earth) and adobe (roughly moulded,
sundried clay bricks). The main drawback of these types of earth construction is their lackof durability and therefore the research and development of stabilized soil blocks or SSB’s.
Stabilized soil blocks are known in various parts of the world differently i.e. Stabilized soil
blocks, stabilized earth blocks, compressed earth blocks or compressed stabilized earth
blocks. Compressed Stabilized Earth Block (CSEB) is a technology, in which blocks are
made by compressing soil mixed with suitable stabilizer in the form of cement or lime at
optimum moisture content by simple mechanical means. Densification of soil at optimum
moisture content and use of stabilizer make CSEB durable. If made in the right manner withproper stabilization, it does not disintegrate due to action of the water. Production of CSEB
generates employment to the local unskilled labour. Firing is not required and thus it isenvironmentally friendly. These blocks can be used in construction of houses, governmentbuildings, toilets, etc.

2. Raw materials
Sl.
No.

Item

Physicalcharacteristics

Chemical characteristics

Qualitystandardization

1.

Soil

Whitish is color, freeof stones and foreign
particles & organic
matterCalorific value: 1000Kcal/kg

Grade 1 or Grade 2of IS 3812

CaO content higher than 60%

Specific gravity: 1.80gm/cm3

2.

Lime

Hydrated form, freefrom impurities

3.

GypsumPowder form, whitein color

4.

CementFree from lumps ,good quality cement
like ACC, Ultratech,
Birla etc.

Setting of cement througha cube test by forming 1:2:4
mortar53 grade OPC

4.

Sand

Free from clay, soilor any other organic
impurities, size
should be 2mm

Clay and silt content
measured by a wet
sedimentation process
should not be more than 4%

As per IS Code12894: 2002

102 | Pre-Feasibility Studies for Implementation of Green Brick Production

Class C hydrated
lime of IS 712
As per IS Code12894: 2002

3. Equipment and machine layout

4. Production process

Pre-Feasibility Studies for Implementation of Green Brick Production | 103

5. Staffing

6. Operations

104 | Pre-Feasibility Studies for Implementation of Green Brick Production

7. Financial projections
7.1. Key assumptions•

The process of manufacture is on the basis of single shift of 8 hours per day with threehundred working days in a year.

•

To achieve full plant capacity, it requires one year after trial production•

Labor and wages mentioned in profile are as per prevailing local rates.

•

Interest rate at 12% considered in the project•

However the rate of interest may be varying while implementing the project.

•

The Promoter contribution will be 10% of the total project cost which is applicable in
the PMEGP scheme.

•

The capacity of the unit is assumed as 24,000 bricks per day on the single shift basis

7.2. Key financial parameters
Capital Investment
Rent per month

5,000

Total project cost

10,00,000

Margin20%

Total loan

8,00,000

Rate of Interest %14%

No of installments

60

EMI

18,615

Cost of Raw Material
INR Per Kg
Soil (including transportation)

0.30

Cement6.00

Coarse sand

0.25

Lime

0.40

Gypsum0.40

Ideal mix design
Soil

55%

Cement8%

Coarse Sand

10%

Lime

3%

Gypsum32%
108%

Pre-Feasibility Studies for Implementation of Green Brick Production | 105

Production
Utilised capacity

90%

Monthly Production

1,80,000

Selling Price
Selling Price per brick

4.00

Turn key ProductionNo

Avg Selling Price per brick

4.00

FIXED CAPITAL
Particulars

Area (Sq.ft)

Rate (Sq.ft)

Amount (Rs.)

Land Development Cost (fencing, gate, etc.)

-

10

-

Working Shed (workshop)

-

100

-

Curing Tank (Water Tank) 4.60* 3.0 * 0.75
meter

150

100

15,000LAND AND BUILDING

15,000Sub Total
MACHINERY AND EQUIPMENTS

Quantity

Rate

Amount (Rs.)

TARA MechRam -MX & Conveyor belt withPan mixer 2 nos. 300 kg capacity, Hydraulicpallet truck & 4 wheel barrow1

13,50,000

13,50,000

Wooden plates @400/piece

50

400

20,000Tax @5% on Machines & Information
Technology Software

69,500Installation and training charges

40,00040,000Transportation

60,00060,00015,39,500

Sub Total
PRE OPERATIVE EXPENSES

Qty.(nos.)

Rate

Amount (Rs.)

Office FurnitureLS

20,000Pre-operative expenses

LS

25,00045,000Sub Total

WORKING CAPITAL (per month@25 days)
1

Raw Materials
Descriptions

No of bricks per month

1,80,000

Per brick weight

3kg

Total Material weight

540000 kg

Qty.

Rate/Kg

Amount (Rs.)

2,97,000

0.30

89,100

-

6.00

-

a

Soil

b

Cementc

Coarse Sand

54,0000.30

16,200d

Lime

16,2001.50

24,300e

Gypsum

1,72,800

2.00

3,45,600

Sub Total

106 | Pre-Feasibility Studies for Implementation of Green Brick Production

4,75,200

2

Staff and Labor
DescriptionsaProduction Supervisorb

Skilled WorkerscUnskilled Workers

3

Quantity (no.)
1
2
8

Rate

Salary (Rs.)

7,500

7,500

6,000

12,0004,000

32,000Sub Total

51,500Add Perquisites @10%

5,150

Sub Total

56,650Utilities (Per month)
Descriptions

Qty.

a

Electric Power 24.0 hp (6hp MX+2x7.5 hp pan mixer+
2 hp conveyor +0.50 hp
water pump+ 0.5 Misc) for
25 days

3,581bWater charges approx.

LS

Rate / unit
6

21,4853,000

Sub Total
4

Amount (Rs.)

24,485

Other Contingent
Expenses (Per month)
Descriptions

Qty.

Unit

Amount (Rs.)

a

Rent

LS

10,000b

Stationery

LS

1,000

c

Telephone / mobile /internet etc.

LS

1,000

d

Transportation

LS

1,000

e

Insurance

LS

1,000

f

Repair and maintenance

LS

1,000

Sub Total

15,0005

Total Recurring
Expenditure (per month)

5,71,335

6

Total Working Capital for
2 months

11,42,670

Total Capital Investment
Fixed capital

15,99,500

Working capital

11,42,670

Total

27,42,170

Project summary
Particulars

INR

Buildings

15,000Indigenous Plant and Machinery

15,39,500

Miscellaneous fixed assets

20,000Pre-operative expenses

25,000Pre-Feasibility Studies for Implementation of Green Brick Production | 107

Capital cost of the project

15,99,500

Working capital per month

5,71,335

Working capital investment

11,42,670

Total capital investment

27,42,170

Loan value

21,93,736

Entrepreneur contribution

5,48,434

Production per month

1,80,000

Selling price per brick

4.00

Monthly revenue

7,20,000

Annual revenue

86,40,000

Rate of Interest %14%

No of installments

60

EMI

51,044Monthly income

97,621

No of months to recover capital

28
Production

Utilised capacity
Monthly Production

108 | Pre-Feasibility Studies for Implementation of Green Brick Production

90%
1,80,000ANNEXURE 5 – Conversion of FCBTK to Zig zag
Kiln Technology Business Plan Details

Detailed Project Report

Conversion of
FCBTK to Zig-Zag Kiln
technology

JUNE 16, 2022
Technology and Action for Rural
Advancement
B-32 TARA Crescent, Qutab
Institutional Area
New Delhi - 110016

Adapted based on the DPR
published by Bureau ofEnergy Efficiency, Govt. ofIndia.

Pre-Feasibility Studies for Implementation of Green Brick Production | 109

1. INTRODUCTION
Existing burnt brick production process and technology
Although there are many brick production technologies existing in the country, but almost
all the brick kilns throughout the state of Assam are the traditional coal fired fixed chimney
Bull's Trench Kilns (BTK) type, with fixed natural draft chimneys except a few kilns which have
converted to zig zag firing technology. Amongst more than 2000 FCBTK, Zig Zag kiln will bearound 10 only.

Brick production process
While the principles of brick manufacture in BTK's is fairly consistent, individual units may
and sometimes do depart from these basics to fit their particular requirements, raw materials
and mode of operations. The essential steps in brick making are shown in the diagram below.
Figure 1: Process flow chart of typical brick kiln process

Clay
Winningand Soil
Preperation

Shaping or
Moudling of
unfired bricks

DryingFiring andcooling

Brick
Extraction

The first three steps of the brick making process usually start around about 20-40 days before
the actual firing of the kiln. This is done to build up a decent stockpile of dried unfired bricks
for continuous operation of the brick kiln. The firing up process of the brick kiln takes 10-20
days to make the kiln reach its appropriate temperature for the bricks to solidify and acquireits pre requisite fired brick attributes. The entire process is continual and once the firing is
initiated, very rarely is the kiln operation course halted.

Clay Winning and Soil preparation
Clay is usually dug from the local vicinity of the brick kiln. The clay is then processed as
to be free from gravel, lime and other bio wastes/ matter. This soil once excavated is thenwatered and left over a period of 8 – 12 hours for weathering and processing. After aging the
moistened soil is kneaded/ pugged as required.

Moulding / Brick formation
The plastic clay after been through the previous process is then moulded into the required
brick shape and size with its makers mark using a metal/ wooden / PVC mould.

Brick Drying
Once the clay has been formed into the pre required unfired brick shape, it is then left out inthe sun to dry and reduce its moisture content. Fast drying on extremely hot days may leadto creation of cracks in the unfired brick which is undesirable. Therefore to minimize crack
creation and quick moisture loss, the drying process takes place over a period of 8 -12 days
with the bricks left out in the Sun. The bricks are usually laid out in stacks with a horizontal
vertical alignment as to maximize usage of space and sunlight

110 | Pre-Feasibility Studies for Implementation of Green Brick Production

Firing and cooling
The firing and cooling is done in the Bull's Trench Kiln (BTK). Relative to combustion zone
within the kiln, the trench can be divided into cooling, firing and pre heating zones. The
cooling zone is the upstream region in which the fired brick extraction takes place. This area
is also vital in the mechanics of the brick kiln functionality as it allows cool air to flow into the
combustion zone. The cool air while flowing through the fired brick arrangement cools thebrick arrangement while at the same time gaining heat from the previous lines of fired bricks.
The combustion zone is the area where the firing of bricks takes place. To achieve thedesired/ required properties of fired bricks the unfired bricks in this zone are subjected totemperatures of 800 – 1080 degree Celsius. Holes are made in lines on the top layer of thebrick arrangement through which coal is fed in regular intervals into the combustion zone. To
minimize heat losses during feeding, these holes are covered with metallic lids. Coal feedingof a line within the combustion zone may take anywhere from 3 to 6 hours depending on thedraft and temperature of the Pre heating line.
The pre-heating zone is located downstream to the combustion zone. Sufficiently dried
unfired bricks are brought over from the Pathai (brick moulding area) and systematicallystacked within this zone. This stacking arrangement is then covered with a top layer of
fly ash (3 – 6 inches) to offer insulation and minimize heat losses. The hot air/gases
coming from the combustion zone flow through these lines of bricks further reducing theirmoisture and heating these bricks. A hole connected to the chimney is opened at a suitablelocation downstream to allow for maximum heating of bricks in the pre heat zone before itis discharged through the chimney. The difference in temperature between the hot air in thechimney and the cold ambient air creates a draft which sucks in air from the cooling zone.

Brick Extraction
The extraction of bricks takes place in the beyond the cooling zone of the brick kiln. As thebrick firing and cooling is a continuous process the brick discharge takes place daily intandem with the position of the firing/cooling of the lines.

1.1

Proposed Technology
The existing technology being used in Assam is mainly the traditional coal fired fixedchimney Bull's Trench Kilns (BTK), with fixed natural draft chimneys. This main reason for
the need of technology up gradation is that the existing technology a high coal consuming
process. As per studies done in Assam, a typical BTK consumes between 20-28 Tonne of coalfor producing one lakh of bricks.

1.1.1

Description of Technology
A BTK is an oval or circular shaped brick kiln with its chimney usually in the centre. The
trench is connected to the chimney by means of evenly spaced chambers along the trench.
The outer wall has exit points for loading & Unloading of bricks. The firing & cooling process
in a BTK comprises of three zones: i) Pre-heating zone, ii) firing/ combustion zone, iii) coolingzone.
Pre-heating zone is the area which is stacked with unfired bricks and utilizes the hot air
coming from the firing zone for drying the unfired bricks by absorbing the moisture present
in it.
Firing zone is the actual area where the firing takes place. In a straight line firing process,bricks are fired one line at a time at a temperature of around 9000C - 10000C. The temperature
is maintained by continuous feeding of coal at regular intervals until the bricks get ready.
Once one line of brick is ready, its holes are closed and the firing is moved forward to the nextline towards the pre-heating zone.
Pre-Feasibility Studies for Implementation of Green Brick Production | 111

Cooling zone is the area where the firing has already taken place and the bricks are kept
for cooling before they are unloaded from the kiln. Since bricks are fired at a very hightemperature, they take few days to cool down. Cooling time is lesser in the winter season
compared to the summers due to the difference in the ambient temperature.

1.1.2 Design and Operating Parameters
BTK has a circular or oval kiln circuit. The bricks to be fired are arranged in column setting.
The fire is progressively moved round the kiln through the brick setting. Before entering thebrick-firing zone, the air is preheated by exchanging heat with hot-fired bricks in the brickcooling zone. Brick firing takes place in a narrow brick-firing zone; in which, coal is added
manually from the holes provided in the roof of the kiln. The combustion products (hot fluegases) pass over the unfired bricks resulting in drying and preheating of bricks in the brickpreheating zone. The fire travel takes place in the direction of the airflow. Cooled fired bricks
are removed from the brick cooling zone, while fresh unfired bricks are added in front of
the brick preheating zone. A chimney stack provides the necessary draft. The below figure
depicts the structure of a BTK.
Figure 2: Typical structure of BTK

2.

PROPOSED TECHNOLOGY

2.1

Detailed Description of Technology

2.1.1 Description of Technology
A BTK with zigzag firing is one of the most fuel efficient kilns. It is different from a straight line
BTK in terms of its fire zone & the coal feeding practices. A BTK with zigzag firing has a long
firing zone (almost two times to six times as compared to a BTK with straight firing) and thecoal feeding process is continuous without any break. The Zigzag kiln consumes less fuel,uses less mechanical energy and requires far less capital outlay with very low maintenance.
It also has a roof resulting in improved working conditions and longer operational time
during raining conditions. The Zigzag kiln is ideally suited to both large scale brick making
settings and to very small village applications in developing countries.
In Zigzag mode of operation, the combustion zone is divided into 2-6 chamber (4 -12 lines)
using partitioning unfired brick arrangement and the kiln is operated at a high draught for afast rate of fire travel. The wall chamber runs along the width of the gallery except one end,

112 | Pre-Feasibility Studies for Implementation of Green Brick Productionwhere a space of 1.0ft is left for communication to the next chamber. The number of bricks
per chamber depends upon the design capacity of the kiln and can vary anywhere from5,400 – 10,000 bricks.
Figure 4: Zig-zag technology

2.1.2 Suitability over Existing Technology
Zigzag firing pattern is easily suitable in the existing system as there is no technology change
as such. It is only process change with requirement of some structural changes. Zigzag isalready being successfully in use in Varanasi cluster in 3 kilns. It is one of the most energy
efficient technologies available.

2.1.3 Superiority over Existing Technology
Among existing kiln designs being used in India, kilns based on Zigzag firing is one of thebrick kiln designs having lowest specific energy consumption. A specific energy consumptiontable in brick kilns is provided in Table 2 below:
Table 2: Specific Energy Consumption
S.No

Kiln

Specific Energy Consumption (MJ/kg) fired product1

Clamp (Biomass)

1.9

2

Clamp (Cole)

1.2 - 1.75

3

Moving chimney (BTK)

1.2-1.75

4

Fixed chimney

1.1-1.4

5

Zigzag0.8-1.1

6

VSBK

0.7-1.0

Zigzag firing technique has been derived from Habla kiln which was invented in Germany
in 1927. This technology was widely used developed countries like Germany and Australia.
It was first introduced in India in the year 1970. Though it is not a very popular technique inbrick industry in Assam, but it is one of the most fuel efficient technologies available.

2.2

Suitable Unit for Implementation of Proposed Technology
BTK having capacity of 7 to 10 lakh bricks per round and production of more than 45 lakhbrick per season are ideal for implementing the Zigzag firing process.

Pre-Feasibility Studies for Implementation of Green Brick Production | 113

3.

ECONOMIC BENEFITS FROM PROPOSED TECHNOLOGY

3.1

Technical Benefits

3.1.1 Fuel Saving
On basis of field studies conducted in the Varanasi cluster and technology gap assessmentof available technology/ process up-gradations, the entrepreneurs can be convinced toadopt Zigzag technologies based on the information provided. Applying a generic ruling for
adoption of technologies, the probability of low and medium investment technologies will
be high as compared to high investment technologies. So for that zigzag is one of the mostsuitable technology. Savings in a typical unit by adopting zigzag firing are tabulated in Table
3 below:
Table 3: Coal savings per year
Energy Efficient Technology/ Annual Coal Savings (tonne)
MeasureProcess Change from straightline to Zigzag Firing

139.50

Annual Energy Savings (Terajoules)
2.915

The zigzag technology suggested does not have any electricity consumption during any
process, so there is no electricity savings as such while adopting this technology.

1.1.3

Improvement in Product Quality
The zigzag firing process utilizes the fuel to its max and the fire travels in such a manner thatit heats up the unfired bricks at equal temperature. A resultant of which is high quality ofbricks being produced as compared to the other process.

1.1.4

Increase in Production
In Zigzag mode of operation, the combustion zone is divided into 2-6 chamber (4 -12 lines)
using partitioning unfired brick arrangement and the kiln is operated at a high draught for afast rate of fire travel. As a result of the long firing & cooling zone, the zigzag process increases
the production capacity of the kiln.

3.2

Monetary Benefits

3.2.1 Monetary Savings due to Reduction in Energy Consumption
Monetary savings in a typical unit after adoption of zigzag firing process has been estimatedaround ` 7 lakhs This figure has been arrived based on the annual coal savings in a typicalunit multiplied by average rate of coal/ Ton.

3.3

Environmental Benefits

3.3.1 Reduction in GHG Emission
There are significant reductions to be achieved in Green House Gas emission by adoptionof zigzag firing technology. Reduction in coal consumption translates into GHG reductions
roughly to the order of 2 tonnes of GHG per ton of coal which is 279 tonne CO2 reductions
per year. The other benefits include, decrease in particulate pollution levels in kiln andsurrounding area.

3.3.2 Reduction in other Emissions like SOx
Due to Zigzag flue exhaust gas path it capture maximum emission product in comparison toother brick kilns.

114 | Pre-Feasibility Studies for Implementation of Green Brick Production

4.

IMPLEMENTATION OF PROPOSED TECHNOLOGY

4.1

Cost of Technology Implementation

4.1.1 Cost of Technology
The costs of equipments that will be required after adoption of zigzag technology is approx.
INR 1.22 lakh. The details are provided in Table 4 & Table 5 below:
Table 4: Detail of Cost of Technology
S.No

Cost of Equipment

Cost

a)

Feed hole covers – 100 nos. @INR 550/-

INR 55,000/-b)

Insulated Shunt – 2 nos. @INR 25000/-

INR 50,000/-c)

Temperature gauge for Shunt – 2 nos. @ INR 1500/-

INR 3,000/-d)

Thermocouple – 1 set (includes 1 small and 1 big)

INR 10,500/-e)Temperature Indicator- 1 no. @INR 3,000/-

Total

Rupees One lakh twenty one thousand only/-

INR 3000/-

INR 1,21,500/-

Note: The prices will vary substantially based on the current procurement and other costs based on Assam andits districts.

4.1.2 Other Costs
Table 5: Cost of civil work and consultancy
S.No.

Particulars

Cost

1.

Cost of modification in Civil structure

INR 4,50,000/-2.

Cost of Consultancy and training to workers and supervisors

INR 1,50,000/-

3EPC Cost

4

Total cost of implementation

INR 36,000/INR 7,58,000/-

4.1.3 Arrangements of funds
Proposed financing for the Zig Zag firing-31 lakh per year is made considering a debt equity
ratio of 3:1, which is normally allowed by financial institutions for financing energy efficiency
projects. On the basis of debt equity ratio of 3:1 the promoter's contribution works out to
25% of the project cost and the balance would be term loan from the Bank / FIs.

4.2

Financial Indicators

4.2.1 Cash Flow Analysis
Cash flow analysis is given in Annexure – 5.

4.2.2 Simple Payback Period
Payback period will be 1.09 Years.

4.2.3 Net Present Value (NPV)Net Present Value at 10% works out to be `18.86 lakh.

4.2.4 Internal Rate of Return (IRR)
After tax IRR of the project works out to be 72.42%. Thus the project is financially viable.
Pre-Feasibility Studies for Implementation of Green Brick Production | 115

4.2.5 Return on Investment (ROI)
The average ROI of the project activity works out at 28.74%. Details of financial indicator are
furnished in Table 7 below:
Table 7: Financial Indicator of Proposed Technology
S.No

Particulars

Unit

Value

1

Simple Pay Back period

Month

13

2

IRR

% age

72.42

3

NPV

lakh

18.86

4

ROI

% age

28.74

5

DSCR

Ratio

3.96

Proposed Technology from Straight line firing toZigzag Firing Description:
Zigzag firing kilns were at one time widely popular in developed countries like Australia andin Europe. These kilns are typically shorter in size (trench size, and overall kiln length) andhave a longer combustion zone than straight line firing kilns.
In Zigzag mode of operation, the combustion zone is divided into 2-6 chamber (4 -12 lines)
using partitioning unfired brick arrangement and the kiln is operated at a high draught for afast rate of fire travel. The wall chamber runs along the width of the gallery except one end,
where a space of 1.0ft is left for communication to the next chamber. The number of bricks
per chamber depends upon the design capacity of the kiln and can vary anywhere from5,400 – 10,000 bricks.
S.No

Particular

Unit

1

Coal consumption per lakh bricks in base case tonne

Value
18

scenario2

Coal consumption per lakh bricks after

tonne

13.5

adoption of Zigzag Firing technology
3

Total brick production

Lakh/year31

4

Coal consumption in base case scenario

tonne/year

558

5

Coal consumption in proposed casetonne/year

418.5

6

Coal saving

tonne/year

139.5

7

Energy Savings

Tera Joule/year

2.92

8

Monetary saving

INR in lakh/year

6.98

9

Investment required

INR in lakh

7.58

10

Simple payback period

Years

1.09

116 | Pre-Feasibility Studies for Implementation of Green Brick Production

Detailed Financial Calculations & Analysis
Assumptions
Name of the Technology

BTK With Zigzag Firing

Rated Capacity

31 lakhDetails

Unit

Value

Basis

Installed Capacity

Bricks/Year

No of working days

Days

250

Plant & Machinery

INR (in lakh)

1.22

Feasibility Study

Cost of modification in civil
construction

INR (in lakh)

4.50

Feasibility Study

Cost of consultancy

INR (in lakh)

1.50

Feasibility Study

EPC Cost

INR (in lakh)

0.36

Feasibility Study

Total Investment

INR (in lakh)

7.58

Own Funds (Equity)` (in lakh)

1.89

Feasibility Study

Loan Funds (Term Loan)` (in lakh)

5.68

AssumedLoan Tenure

Years

5

AssumedMoratorium Period

Months6

AssumedRepayment Period

Months66

AssumedInterest rate

% age

10

SIDBI EE Lending rate

31 lakh

Proposed Investment

Financing pattern

Estimation of Costs
O & M Costs

on Plant & Equip

2.00%

Feasibility Study

Annual Escalation

%

2.00%

Feasibility Study

Coal savings

tons

139.50Cost

INR / tonne

5000

St. line Depn.

%

5.28

Indian Companies Act

IT Depreciation%

100.00

Income Tax Rules

Income Tax

%

33.99

Income Tax

Estimation of Revenue

Estimation of Interest on term loan INR (in lakh)
Years

Opening
Balance

Repayment

Closing Balance

Interest

1

5.68

0.48

5.20

0.51

2

5.20

0.96

4.24

0.48

3

4.24

1.02

3.22

0.38

4

3.22

1.08

2.14

0.27

5

2.14

1.20

0.94

0.16

6

0.94

0.94

0.00

0.03

5.68

Pre-Feasibility Studies for Implementation of Green Brick Production | 117

WDV Depreciation INR (in lakh)
Particulars / years

1

Plant and Machinery
Cost

7.22

Depreciation

7.22

WDV

-

Projected Profitability` (in lakh)
Particulars / Years

1

Fuel savings
Total Revenue (A)

2

3

4

5

6

7

8

Total

6.98 6.98

6.98

6.98

6.98

6.98

6.98

6.98

55.80

6.98 6.98

6.98

6.98

6.98

6.98

6.98

6.98

55.80

O & M Expenses

0.15 0.15

0.16

0.16

0.16

0.17

0.17

0.17

1.30

Total Expenses (B)0.15 0.15

0.16

0.16

0.16

0.17

0.17

0.17

1.30

PBDIT (A)-(B)

6.82 6.82

6.82

6.81

6.81

6.81

6.80

6.80

54.50

Interest

0.51 0.48

0.38

0.27

0.16

0.03

-

-

1.83

PBDT

6.31 6.34

6.44

6.54

6.65

6.78

6.80

6.80

52.67

Depreciation

0.40 0.40

0.40

0.40

0.40

0.40

0.40

0.40

3.20

PBT

5.91 5.94

6.04

6.14

6.25

6.38

6.40

6.40

49.47

- 2.16

2.19

2.22

2.26

2.30

2.31

2.31

15.76

5.91 3.79

3.85

3.92

3.99

4.08

4.09

4.09

33.71

Expenses

Income tax
Profit after tax (PAT)

Computation of Tax` (in lakh)
Particulars / Years

1

2

3

4

5

6

7

8

Profit before tax

5.91

5.94

6.04

6.14

6.25

6.38

6.40

6.40

Add: Book depreciation

0.40

0.40

0.40

0.40

0.40

0.40

0.40

0.40

Less: WDV depreciation

7.22

-

-

-

-

-

-

-

Taxable profit(0.90)

6.34

6.44

6.54

6.65

6.78

6.80

6.80

-

2.16

2.19

2.22

2.26

2.30

2.31

2.31

5

6

7

8

Income Tax

Projected Balance Sheet
Particulars / Years

1

2

3

4

Share Capital (D)

1.89

1.89

1.89

1.89

1.89

1.89

1.89

1.89

Reserves & Surplus (E)

5.91

9.70

13.55

17.47

21.46

25.53

29.63

33.71

Term Loans (F)

5.20

4.24

3.22

2.14

0.94

0.00

0.00

0.00

Total Liabilities(D)+(E)+(F)

13.01

15.84

18.67

21.50

24.29

27.43

31.52

35.61

Gross Fixed Assets

7.58

7.58

7.58

7.58

7.58

7.58

7.58

7.58

Less Accm. depreciation

0.40

0.80

1.20

1.60

2.00

2.40

2.80

3.20

Net Fixed Assets

7.18

6.78

6.38

5.98

5.58

5.18

4.78

4.38

Cash & Bank Balance

5.83

9.06

12.29

15.53

18.72

22.25

26.75

31.23

Total Assets

13.01

15.84

18.67

21.50

24.29

27.43

31.52

35.61

Net Worth

7.81

11.59

15.44

19.36

23.35

27.43

31.52

35.61

Debt Equity Ratio

0.67

0.37

0.21

0.11

0.04

0.00

0.00

0.00

Liabilities

Assets118 | Pre-Feasibility Studies for Implementation of Green Brick ProductionProjected Cash Flow:` (in lakh)
Particulars / Years

0

1

2

3

4

5

6

7

8

Sources
Share Capital

1.89

-

-

-

-

-

-

-

-

Term Loan
Profit After tax

5.68
5.91

3.79

3.85

3.92

3.99

4.08

4.09

4.09

Depreciation

0.40

0.40

0.40

0.40

0.40

0.40

0.40

0.40

6.31

4.19

4.25

4.32

4.39

4.48

4.49

4.49

-

-

Total Sources

7.58

Application
Capital Expenditure

7.58

Repayment Of Loan

-

0.48

0.96

1.02

1.08

1.20

0.94

Total Application

7.58

0.48

0.96

1.02

1.08

1.20

0.94

-

-

Net Surplus

-

5.83

3.23

3.23

3.24

3.19

3.54

4.49

4.49

Add: Opening Balance

-

-

5.83

9.06

12.29

15.53

18.72

22.25

26.75

Closing Balance

-

5.83

9.06

12.29

15.53

18.72

22.25

26.75

31.23

1

2

3

4

5

6

7

8

Profit after Tax

5.91

3.79

3.85

3.92

3.99

4.08

4.09

4.09

Depreciation

0.40

0.40

0.40

0.40

0.40

0.40

0.40

0.40

Interest on Term Loan

0.51

0.48

0.38

0.27

0.16

0.03

-

-

-

-

-

-

IRR ` (in lakh)
Particulars / months

0

Salvage / Realisable
value
Cash outflow(7.58)

-

-

-

-

-

-

-

-

Net Cash flow

(7.58)

6.82

4.66

4.63

4.59

4.55

4.50

4.49

4.49

IRR

72.42%

NPV

18.86

Break Even Point
Particulars / Years

1

2

3

4

5

6

7

8

Oper. & Maintenance Exp
(75%)

0.11

0.12

0.12

0.12

0.12

0.13

0.13

0.13

Sub Total(G)

0.11

0.12

0.12

0.12

0.12

0.13

0.13

0.13

Oper. & Maintenance Exp
(25%)

0.04

0.04

0.04

0.04

0.04

0.04

0.04

0.04

Interest on Term Loan

0.51

0.48

0.38

0.27

0.16

0.03

0.00

0.00

Depreciation (H)

0.40

0.40

0.40

0.40

0.40

0.40

0.40

0.40

Sub Total (I)

0.95

0.92

0.82

0.71

0.60

0.47

0.44

0.44

Sales (J)

6.98

6.98

6.98

6.98

6.98

6.98

6.98

6.98

Contribution (K)

6.86

6.86

6.86

6.85

6.85

6.85

6.85

6.84

Break Even Point (L= G/I)

13.84%

13.34%

11.94%

10.40% 8.77%

6.84%

6.46%

6.48%

Cash Break Even {(I)-(H)}

8.01%

7.51%

6.11%

4.57% 2.93%

1.00%

0.62%

0.64%

Break Even Sales (J)*(L)

0.97

0.93

0.83

0.48

0.45

0.45

Variable Expenses

Fixed Expenses

0.73

0.61

Pre-Feasibility Studies for Implementation of Green Brick Production | 119

Return on Investment` (in lakh)
Particulars / Years

1

2

3

4

5

6

7

8

Total

Net Profit Before Taxes

5.91

5.94

6.04

6.14

6.25

6.38

6.40

6.40

49.47

Net Worth

7.81

11.59

15.44

19.36 23.35

27.43

31.52

35.61 172.11

28.74%

Debt Service Coverage Ratio
Particulars / Years` (in lakh)

1

2

3

4

5

6

7

8

Total

Profit after Tax

5.91

3.79

3.85

3.92

3.99

4.08

4.09

4.09

25.53

Depreciation

0.40

0.40

0.40

0.40

0.40

0.40

0.40

0.40

2.40

Interest on Term Loan

0.51

0.48

0.38

0.27

0.16

0.03

0.00

0.00

1.83

Total (M)

6.82

4.66

4.63

4.59

4.55

4.50

4.49

4.49

29.76

Cash Inflow

Debt
Interest on Term Loan

0.51

0.48

0.38

0.27

0.16

0.03

0.00

0.00

1.83

Repayment of Term Loan

0.48

0.96

1.02

1.08

1.20

0.94

0.00

0.00

5.68

Total (N)

0.99

1.44

1.40

1.35

1.36

0.97

0.00

0.00

7.51

Average DSCR (M/N)

3.96

120 | Pre-Feasibility Studies for Implementation of Green Brick Production

ANNEXURE 6

VSBK Business Plan
Details

JUNE 16, 2022
Technology and Action for Rural
Advancement
B-32 TARA Crescent, Qutab
Institutional Area
New Delhi - 110016

Adapted based on the DPR
published by Bureau ofEnergy Efficiency, Govt. ofIndia.

Pre-Feasibility Studies for Implementation of Green Brick Production | 121

ANNEXURE 6 – VSBK Business Plan Details
The process of owning and adopting a VSBK technology should be three fold. The process
is as follows:
Step 1: Testing of soil and making a decision that quality bricks are possible to be producedwith required soil quality.
Step 2: Designing the VSBK and preparing the detailed project report for understanding the
economics
Step 3: Providing technical, operational and troubleshooting support

Soil testing and recommendations
In general, soils containing high proportions of sand lead to poor brick strength, while on theother hand, high levels of clay content cause excessive shrinkage and result in cracking of
the brick even during the unfired brick preparation stage. Thus, to assess the future qualityof brick production, soil testing is an important step which should be mandatory before
adoption of VSBK technology.

VSBK production system design
Design principles
The design of VSBK is the result of efforts and processes developed in the past and thepractical experiences of VSBK’s performances in India and different countries. The design ofthe shaft size is the most important part of VSBK because it determines the dimensions of
the entire VSBK structure. The shaft design also plays an important role in the performanceof VSBK. Any fault in the design of the shaft can lead to failure of the kiln. Also, once designed
and constructed, the shaft size cannot be changed.
The following criteria are derived from design aims and errors applicable to the present
issue of developing the same for an VSBK system and limited not only to the final civil
superstructure.

Identification and review of critical decisions
Every decision which carries a high penalty must be identified as early as possible. Suchdecisions should be taken only tentatively at first and should be reversible if they are later
found to be conflicting with reliable evidence or with informed opinions.

Relating the cost of research to the penalties for taking wrong decisions
The penalty for not knowing must exceed the cost for finding out if it is worth using expensive
design efforts to answer any questions. The first requirement in evaluating a proposed action
is to identify the questions to which the action will provide answers.

Matching design activities to the implementation teamThe design team members must be confident of their actions. They should have thecapabilities and the motivation to carry out these actions. This must also match the capabilityof the implementation team and therefore be within their reach and understanding.

122 | Pre-Feasibility Studies for Implementation of Green Brick Production

Identifying usable sources of information
Information should be sought from all the major sources of stability or instability to ensure
their compatibility with the designs. The reliability of alternative sources of information
should be assessed independently before undertaking the design exercise.

Specific design criteria
The VSBK design parameter majorly depends on following things•

Brick dimension•

Shaft cross section•

Batch height•

Kiln height from ground level•

Flue duct level•

Loading platform level

Kiln design
Figure 51: Cross section of side view of VSBK

The above gives an idea of the perspective of a VSBK. This is a general drawing and needs tobe customised for each and every individual VSBK based on brick type, soil type, shrinkage,strength and production requirement.

Pre-Feasibility Studies for Implementation of Green Brick Production | 123

Operational parameters
VSBK is a firing technology and provides strength to the burnt clay brick through anapplication of a thermal process. However, it cannot modify or improve upon whatever is
fed into in the form of a unfired brick. Some of the basic operation parameters of the VSBK
therefore are as follows:•

Regular field testing of soil•

Proper processing of soil and use of internal fuel in unfired bricks•

Use of dried and good quality unfired bricks•

Ensuring required coal quality and its size•

Following proper loading and unloading of unfired and fired bricks•

Ensuring operation of kilns as per standards throughout the day and night also.

•

Regular preventive maintenance and proper repair of equipment and machineriesBill of materials
Principles of selection of materials
The Bill of materials represents the necessary and sufficient items that would be required
to suitably construct an VSBK in Assam. During making the bill of materials for Assam thefollowing principles were followed:•

All materials, including bricks, cement, steel, wood etc. should be available in the local
market in India as far as possible•

Reduce purchase of goods as deemed appropriate without compromising the quality•

Selection of equipment and machineries which should be easily maintained andrepaired in local markets in Assam•

Imports of equipment and machineries were considered where it is available at cheaper
rates meeting required quality standards•

The construction will use materials of the highest quality available in the market.

•

All the materials will be used to arrive at the end of the product system

Bill of materials calculation criteria
A bill of materials is the record of the raw materials, sub-assemblies and supplies used toconstruct a product i.e. the VSBK. The bill of materials is and will be used to calculate the costof the brick to be produced and understanding the business economics. It is also an essential
requirement when an enterprise is planning to develop a plan for material requirements.
During the calculation of bill of materials for VSBK the following criteria were followed:•

Bill of materials may include not only the unit quantity required to construct the VSBK
but an estimate of the scrap that will be produced and where it can be used.

•

The Bill of materials should be extremely accurate with reasonable flexibility. This is toensure that wrong or excess items are not procured which might cause a major delay inthe construction process.

•A bill of materials is a centralised source of information used to manufacture the VSBK.
Thus, correct parts must be available during the construction process. Improper Bill of

124 | Pre-Feasibility Studies for Implementation of Green Brick Production

materials might cause the construction to be delayed which will increase the operating
costs of the enterprise and therefore profitability.
•

The Bill of materials will define all the products including their codes, specifications andfeatures.

Bill of materials for VSBK in Assam (2 shaft VSBK)All rates have been calculated based on Indian Currency (In Rs.)

Principles for determining business planA successful business cannot be built and run spontaneously. Planning is essential, and notjust an initial business plan but regular, ongoing evaluations and updated strategies. For
Pre-Feasibility Studies for Implementation of Green Brick Production | 125

building a prosperous business, use of good principles of business planning is essential. The
principles for determining business plan are as following•

The plan needs to be checked and modified on a regular basis•

The cost considered while making a business plan should be as accurate as possible•

The plan must contain short term and long term goals•

The plan should reflect payback period for the investment

Key assumptions:•

Installed capacity: 9000 bricks per day (27,00,000 bricks per annum)•

No. of working days per annum: 300•

Average utilisation capacity: 85%•

Average production cost per brick: INR 4.16•

Average selling price per brick: Rs.9•

Project finance: 100% from entrepreneur•

Land acquisition cost not taken into account.

The 2 shaft VSBK business plan
Summary
The business plan has been calculated for 11 batch height double shaft VSBK. The rates

considered here are as per inputs provided in discussion with entrepreneurs in Assam andalso the rates available and applicable for Assam. The detailed calculations and the list ofschedules have been attached in the annexes.
The total project has been calculated to be around INR 79.82 lakhs with a brick selling price of
INR 9 as per the market assessment, the payback period will be around 2 years. A simulationof the payback period with brick selling price has also been done where it is observed thatthe payback period is inversely proportional to that of the brick selling price. But to keep
the business more realistic and competitive, one should not increase the brick selling price.
126 | Pre-Feasibility Studies for Implementation of Green Brick Production

ANNEXURE - VSBK Business Plan Detail
LIST OF SCHEDULESSCHEDULE - A
COST OF PROJECT
USD 75.00
Item of Cost

Annexure

Total

Nos.

Rs.

USD

Land & Site development

1

105,000

1,400

Building & other civil works cost

2

4,523,603

60,315

Machinery & equipment

32,551,000

34,013

Miscellaneous Fixed Assets

4

190,000

2,533

Preliminary & Pre-operative Expenses

5282,000

3,760

Contingencies

6

382,580

5,101

8,034,183

107,122

1,887,924

25,172

9,922,107

132,295

Capital Cost of the projectWorking Capital

16

Total Project Cost

SCHEDULE - B
MEANS OF FINANCE
Sources of funds

Already Raised

To be Raised

Total

Rs.

Rs.

Rs.

CapitalPromoter’s Capital

100.00%-9,922,107

9,922,107

Subsidy/donor grant/government scheme

0.00%

-

-

-

Bank

0.00%

-

-

-

Other financial institutions

0.00%
-

9,922,107

Secured Loans

Total source of funds

9,922,107

Pre-Feasibility Studies for Implementation of Green Brick Production | 127

SCHEDULE -C
PROFIT AND LOSS PROJECTION
Particulars

Annexure
Numbers

Operating Years
1

2

3

4

5

6

7

8

9

10

14,369,898

17,195,940

18,317,970

18,360,000

18,360,000

18,360,000

18,360,000

18,360,000

18,360,000

18,360,000

Raw materials

3,836,700

4,384,800

4,658,850

4,658,850

4,658,850

4,658,850

4,658,850

4,658,850

4,658,850

4,658,850

Consumables

115,101

131,544

139,766

139,766

139,766

139,766

139,766

139,766

139,766

139,766

Utilities

638,400

729,600

775,200

775,200

775,200

775,200

775,200

775,200

775,200

775,200

4,899,000

5,304,000

5,506,500

5,506,500

5,506,500

5,506,500

5,506,500

5,506,500

5,506,500

5,506,500

86,566

98,933

105,116

105,116

105,116

105,116

105,116

105,116

105,116

105,116

84,362

86,06086,90986,90986,90986,90986,90986,90986,90986,90935,00040,00042,50042,50042,50042,50042,50042,50042,50042,5009,695,130

0,774,937

1,314,841

1,314,841

11,314,841

11,314,841

11,314,841

1,314,841

11,314,841

11,314,841

969,513

1,077,494

1,131,484

1,131,484

1,131,484

1,131,484

1,131,484

1,131,484

1,131,484

1,131,484-

319,192354,963

372,848

372,848

372,848

372,848

372,848

372,848

372,848-

430,910479,199503,344503,344503,344503,344503,344503,344503,344

319,192354,963

372,848

372,848

372,848

372,848

372,848

372,848

372,848

372,848

430,910479,199503,344503,344503,344503,344503,344503,344503,344503,344

11,768,371

12,404,295

12,446,325

12,446,325

12,446,325

12,446,325

12,446,325

12,446,325

12,446,325

4,455,358

5,427,569

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

-

-

-

-

-

-

-

-

-

-

4,455,358

5,427,569

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

1,200,521

1,200,521

1,200,521

1,200,521

1,200,521

1,200,521

1,200,521

1,200,521

1,200,521

1,200,521

26,40026,40026,40026,40026,400

-

-

-

-

-

3,228,436

4,200,648

4,686,754

4,686,754

4,686,754

4,713,154

4,713,154

4,713,154

4,713,154

4,713,154

968,5311,260,194

1,406,026

1,406,026

1,406,026

1,413,946

1,413,946

1,413,946

1,413,946

1,413,946

2,259,905

2,940,453

3,280,728

3,280,728

3,280,728

3,299,208

3,299,208

3,299,208

3,299,208

3,299,208

A. Estimatedsales revenue/
incomeProduction cost:

Salaries andwages
Repairs &Maintenance
Other
manufacturing
expenses
Administrative
Overheads
Sub-total
Add: Provision
for Production

10.00%

LossesAdd: Opening
stocks of WorkIn Progress(W.I.P)
Add: Opening
stocks ofFinished Goods(F.G)
Less: Closing
stocks of F.G.
Less: Closing
stocks of W.I.P.
B. Total cost of

9,914,541

production
C. EBIDT (A-B)
D. Total interest
expenses
E. Incomebeforedepreciationand tax (C-D)
Depreciation
Preliminary
expenses(written off over5

the given years)
F. Profit Before
Tax (PBT)
G. Provision for
taxation
H. Profit After
Tax (PAT)

30.00%

128 | Pre-Feasibility Studies for Implementation of Green Brick Production

SCHEDULE - D
CASH FLOW STATEMENT
Particulars

Annexure
Numbers 1

Operating Years
2

3

4

5

6

7

8

9

10

Cash at the
beginning of theyear-(3,578,826)

1,848,744

7,762,418

13,676,093

19,589,768

25,503,443

31,417,118

37,330,793

43,244,468

Cash at the end of
the year(3,578,826) 1,848,744

7,762,418

13,676,093

19,589,768

25,503,443

31,417,118

37,330,793

43,244,468

49,158,143

14,369,898 17,195,940

18,317,970

18,360,000

18,360,000

18,360,000

18,360,000

18,360,000

18,360,000

18,360,000

OPERATING
ACTIVITIESCash receipt:
Sales
Cash paid for:
Production(9,914,541) (11,768,371) (12,404,295) (12,446,325) (12,446,325) (12,446,325) (12,446,325) (12,446,325) (12,446,325) (12,446,325)

Interest expenses

-

-

-

-

-

-

-

-

-

-

Net Cash Flowfrom Operating
Activities

4,455,358

5,427,569

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

-

-

-

-

-

-

-

-

-

-

Capital cost of the
project(8,034,183) -

-

-

-

-

-

-

-

-

Net Cash Flowfrom Investing
Activities(8,034,183) -

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Term Loan
principal

-

-

-

-

-

-

-

-

-

-

Net Cash Flowfrom Financing
Activities

-

-

-

-

-

-

-

-

-

-

NET CASH FLOW

(3,578,826) 5,427,569

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

5,913,675

INVESTING
ACTIVITIESCash receipt:
Cash paid for:

FINANCING
ACTIVITIESCash receipt
Term Loan
Cash paid for

Pre-Feasibility Studies for Implementation of Green Brick Production | 129

SCHEDULE - E
BREAK EVEN POINT
Particulars

Annexure
NumberOperating Years
1

2

3

4

5

6

7

8

9

10

Installed
Capacity/Day

9000

9000

9000

9000

9000

9000

9000

9000

9000

9000

Working days

300

300

300

300

300

300

300

300

300

300

Annual Installed
Capacity

2700000

2700000

2700000

2700000

2700000

2700000

2700000

2700000

2700000

2700000

Capacity
utilization asa%70.00%

80.00%

85.00%

85.00%

85.00%

85.00%

85.00%

85.00%

85.00%

85.00%

Total
production/Annum

1890000

2160000

2295000

2295000

2295000

2295000

2295000

2295000

2295000

2295000

Estimated sales
revenue

14,369,898

17,195,940

18,317,970

18,360,000 18,360,000

18,360,000 18,360,000 18,360,000

18,360,000 18,360,000

Raw materials

3,836,700

4,384,800

4,658,850

4,658,850

4,658,850

4,658,850

4,658,850

4,658,850

4,658,850

4,658,850

Consumables

115,101

131,544

139,766

139,766

139,766

139,766

139,766

139,766

139,766

139,766

Variable costs:

Utilities

90%

574,560

656,640

697,680

697,680

697,680

697,680

697,680

697,680

697,680

697,680

Salaries and
wages

70%

3,429,300

3,712,800

3,854,550

3,854,550

3,854,550

3,854,550

3,854,550

3,854,550

3,854,550

3,854,550

86,566

98,933

105,116

105,116

105,116

105,116

105,116

105,116

105,116

105,116

16,872

17,212

17,382

17,382

17,382

17,382

17,382

17,382

17,382

17,382

Provision for
production loss

969,513

1,077,494

1,131,484

1,131,484

1,131,484

1,131,484

1,131,484

1,131,484

1,131,484

1,131,484

Interest on cash
credit facility forworking capital

-

-

-

-

-

-

-

-

-

-

7,000

8,000

8,500

8,500

8,500

8,500

8,500

8,500

8,500

8,500

Less: Variationin stocks(750,102)(84,060)(42,030)

0.00

0.00

0.00

0.00

0.00

0.00

0.00

Total variable
costs

9,785,714

10,171,483

10,655,358

10,613,328 10,613,328

10,613,328 10,613,328 10,613,328

10,613,328 10,613,328

Repairs andmaintenance
Other
manufacturing
expenses

Administration
overheads

20%

20%

Variable cost
per unit

Rs.

5

5

5

5

5

5

5

5

5

5

Gross income

Rs.

4,584,184

7,024,457

7,662,612

7,746,672

7,746,672

7,746,672

7,746,672

7,746,672

7,746,672

7,746,672

Gross income
per unit

Rs.

2

3

3

3

3

3

3

3

3

3

Utilities

10%

63,84072,96077,52077,52077,52077,52077,52077,52077,52077,520

Salaries and
wages

30%

1,469,700

1,591,200

1,651,950

1,651,950

1,651,950

1,651,950

1,651,950

1,651,950

1,651,950

1,651,950

Other
manufacturing
expenses

80%

67,49068,84869,527

69,527

69,527

69,527

69,527

69,527

69,527

69,527Administration
overheads

80%

28,00032,00034,00034,00034,00034,00034,00034,00034,00034,000Interest on term
loan

-

-

-

-

-

-

0.00

0.00

0.00

0.00

Depreciationand preliminary
expenses

1,226,921

1,226,921

1,226,921

1,226,921

1,226,921

1,200,521

1,200,521

1,200,521

1,200,521

1,200,521

Total fixed andsemi variable
cost

2,855,951

2,991,930

3,059,919

3,059,919

3,059,919

3,033,519

3,033,519

3,033,519

3,033,519

3,033,519

8,952,461

7,324,273

7,314,934

7,252,160

7,252,160

7,189,591

7,189,591

7,189,591

7,189,591

7,189,591

1,177,472

920,010916,465

906,520

906,520

898,699

898,699

898,699

898,699

898,699

Fixed costs:

Break evenpoint in numberof bricks per
year

Rs.

numberBreak evenpoint in sales
revenue peryear

130 | Pre-Feasibility Studies for Implementation of Green Brick Production

SCHEDULE - F
PAYBACK PERIOD, NPV AND IRR
Operating Profit
Total Project CostYear
After Tax (in Rs.)
(PAT)
Construction
PeriodCumulative Cash Inflow Projected Cost Recovery(in Rs.)(in Rs.)9,922,107(9,922,107)

1

2,259,905

2,259,905(7,662,202)

2

2,940,453

5,200,359(4,721,748)

3

3,280,728

8,481,086(1,441,021)

4

3,280,728

11,761,814

1,839,707

5

3,280,728

15,042,541

5,120,435

6

3,299,208

18,341,749

8,419,642

7

3,299,208

21,640,956

11,718,850

83,299,208

24,940,164

15,018,057

93,299,208

28,239,371

18,317,265

10

3,299,208

31,538,579

21,616,472

Payback period
is between
operating years

1

to

2

NPV of the
Project (in Rs.)

58,303,350

IRR of the Project

19.26%

Particulars
Land:
Acquisition cost
Other cost (land title deed andregistration)
Sub-total
Site development:
Fencing (Complete Plot)
Gates, internal roads
Drainage
Sub-total
Total: Land and Site
Development cost

LIST OF ANNEXURESANNEXURE - 1
PARTICULARS OF LAND AND SITE DEVELOPMENT COST
Unit
QuantityRateRs.
square meterlump sum

9000.00
1.00

-

Total
Rs.
-

lump sumlump sumlump sum

1.00
1.00
1.00

40,00065,000-40,00065,000105,000
105,000

Pre-Feasibility Studies for Implementation of Green Brick Production | 131

ANNEXURE - 2
PARTICULARS OF BUILDINGS & OTHER CIVIL WORKS COST
Particulars
Vertical Shaft Brick Kiln
(2-Shaft with 11 Batch)

No. of Built Up Area
Floor Length (m) Width (m)
-

12.30

8.10

Total Floor Area

Lump Sum Cost

Quantity(square meter)

Rs.

1.00

99.61

4,523,603

Total: Buildings andother civil works cost

4,523,603

ANNEXURE - 3
PARTICULARS OF MACHINERY & EQUIPMENT COST
Particulars

Supplier’s
Name

Quantity

Unit

Invoice Price

Total

INR / Unit

Rs.

Brick Making Machine

1.00

set

800,000

800,000

Conveyor Belt System

1.00

set

350,000

350,000

Transfer Trolleys

4.00

number

60,000240,000

Hydraulic Jack

2.00

set

380,000

760,000

Total

2,150,000

Add: Handling & Forwarding Charges @10%

215,000

Add: Warehouse charges

100,000

Add: Transportation & Insurance @ 4%

86,000Grand Total: Machinery & Equipment Cost

2,551,000

ANNEXURE - 4
PARTICULARS OF MISCELLANEOUS FIXED ASSETS
Description

Unit

Quantity

Rate

Total

Rs.

Rs.

Office furniture and fixtures

lump sum

1.00

20,00020,000Borehole, water storage, distribution pipes,
pump

lump sum

1.00

50,00050,000

Cost of drawing power, cabling, and electric
installations for wiring, lighting, and deposits

lump sum

1.00

120,000

120,000

Total

190,000
ANNEXURE - 5
PRELIMINARY AND PREOPERATIVE EXPENSES

Description

Unit

QuantityRate

To be incurred

Rs.

Rs.

Preliminary expenses:
Soil Feasibility test*

lump sum

0.50

10,0005,000

Environment Impact Analysis

lump sum

1.00

100,000

100,000

Business Plan and BoQ for EcoKiln* lump sum

0.50

30,00015,000Legal Expenses

lump sum

1.00

10,00010,000

Other Charges including banklump sum

1.00

2,000

2,000

Total
Preoperative expenses:

132 | Pre-Feasibility Studies for Implementation of Green Brick Production

132,000

ANNEXURE - 5
PRELIMINARY AND PREOPERATIVE EXPENSES
Description

Unit

QuantityRate

To be incurredTechnical know-how fees*

lump sum

0.50

300,000

150,000

Total

150,000

Grand Total: Prelim. & Preop.
Expenses

282,000* Calculation at 50% discount as part of the project support
ANNEXURE -6
ESTIMATES OF CONTINGENCY ESCALATION PROVISION
Item of Cost

Annexure Nos.

Total

Land & site development

1

105,000

Buildings and other civil works

2

4,523,603

Machinery & equipment

32,551,000

Miscellaneous Fixed Assets

4

190,000

Preliminary & Pre-operative Expenses

5282,000

Rs.

Total

7,651,603

Contingency

5%

ANNEXURE - 7
CALCULATION OF DEPRECIATION
Site Development
Machinery && Buildings
Equipment

Description

382,580

Misc. Fixed Assets

Total

Straight Line Method:
Rate of depreciation %

10

25

10

Acquired cost
Preoperative Expenses
Contingencies

4,628,603
94,210240,286

2,551,000
51,923
132,431

190,000
3,867
9,864

7,369,603
150,000
382,580

4,963,099
496,310

2,735,353
683,838

203,731
20,3737,902,183
1,200,521

Total apportioned cost
Depreciation amount

150,000
382,580

Pre-Feasibility Studies for Implementation of Green Brick Production | 133

ANNEXURE - 8
ESTIMATED ANNUAL PRODUCTION AND SALES VALUE
Description

Unit

Operating Years
1

2

3

4

5

6

7

8

9

10

Installed Capacity/Day

number

9000

9000

9000

9000

9000

9000

9000

9000

9000

9000

Number of Working
Days

number

300

300

300

300

300

300

300

300

300

300

Annual Installed
Capacity

number2700000

2700000

2700000

2700000

2700000

2700000

2700000

2700000

2700000

2700000

Capacity utilisation

percentage 70%

80%

85%

85%

85%

85%

85%

85%

85%

85%

Target Production

number

1890000

2160000

2295000

2295000

2295000

2295000

2295000

2295000

2295000

2295000

8.00

8

8

8

8

8

8

8

8

8

8

Sales Value:
Average selling priceper yearTarget brick sales per
year

15,120,000 17,280,000 18,360,000 18,360,000 18,360,000 18,360,000 18,360,000

18,360,000 18,360,000 18,360,000

Add: Opening stockof Work In Progress &Finished Goods-

750,102

834,162

876,192

876,192

876,192

876,192

876,192

876,192

876,192

Less: Closing stockof Work In Progress &Finished Goods

750,102

834,162

876,192

876,192

876,192

876,192

876,192

876,192

876,192

876,192

Total estimated sales
revenue

14,369,898 17,195,940 18,317,970 18,360,000 18,360,000 18,360,000 18,360,000

18,360,000 18,360,000 18,360,000

Ratio of Pavers & Bricks;
40;60
ANNEXURE -9
PARTICULARS OF RAW MATERIALS FOR ECO-BRICKS
Raw
Material

Consumption

Rate/kg

Operating Years

per brick (in kg)

Rs.

1

8

9

Soil

2.80

0.50

2,646,000 3,024,000 3,213,000 3,213,000 3,213,000 3,213,000 3,213,000

3,213,000

3,213,000 3,213,000

Coal

0.09

7.00

1,190,700 1,360,800 1,445,850 1,445,850 1,445,850 1,445,850 1,445,850

1,445,850

1,445,850 1,445,850

3,836,700 4,384,800 4,658,850 4,658,850 4,658,850 4,658,850 4,658,850

4,658,850

4,658,850 4,658,850

Total

2

3

4

5

6

7

10

ANNEXURE - 10
PARTICULARS OF CONSUMABLES
Item

Rate

Consumables*

3.00%

Operating Years

Total

1

2

3

4

5

6

7

8

9

10

115,101

131,544

139,766

139,766

139,766

139,766

139,766

139,766

139,766

139,766

115,101

131,544

139,766

139,766

139,766

139,766

139,766

139,766

139,766

139,766

Consumables* Consumables include tools, equipments
and other items for production

ANNEXURE - 11
PARTICULARS OF UTILITIESParticulars

Unit

QuantityRate

Per Day

Rs.

1

2

3

4

5

Operating Years
6

7

8

9

10

Water

litre

3500.00

0.50

367,500

420,000

446,250446,250446,250446,250446,250446,250446,250446,250

Power-Diesel:
Brick making
machine (7.5 HP)

litre

12.00

90.00

226,800

259,200

275,400

275,400

275,400

275,400

275,400

275,400

275,400

275,400

Electricity

kilowatt
hour
(kWh)

35.00

6.00

44,10050,40053,55053,55053,55053,55053,55053,55053,55053,550638,400

729,600

775,200

775,200

775,200

775,200

775,200

775,200

775,200

775,200

Total

134 | Pre-Feasibility Studies for Implementation of Green Brick Production

ANNEXURE - 12
SALARIES AND WAGES
Manpower
Salary/Requirement wagebasis

No. of Rate
peopleAnnual
Wages

Rs.

Rs.

Brick
production
per year

Operating Years
1

2

3

4

1,890,000

2,160,000

2,295,000

2,295,000 2,295,000 2,295,000 2,295,000 2,295,000 2,295,000 2,295,000

5

6

7

8

9

10

Supervisor

per
month

1

20,000 240,000

240,000

240,000

240,000

240,000

240,000

240,000

240,000

240,000

240,000

240,000

Fire Master

per
month

2

12,000 288,000

288,000

288,000

288,000

288,000

288,000

288,000

288,000

288,000

288,000

288,000

Skilled (brickfiring)

per
month

12

10,000 1,440,000 1,440,000

1,440,000

1,440,000

1,440,000 1,440,000 1,440,000 1,440,000 1,440,000 1,440,000 1,440,000

Maintenance
Staff(contractual)

per
month

1

8,000

96,00096,00096,00096,00096,000

Unskilled:
Unfired brickmakingper brick 10

1-

1,890,000

2,160,000

2,295,000

2,295,000 2,295,000 2,295,000 2,295,000 2,295,000 2,295,000 2,295,000

Unskilled:
per brick 12
Brick handling

1-

945,000

1,080,000

1,147,500

1,147,500 1,147,500 1,147,500 1,147,500 1,147,500 1,147,500 1,147,500

4,899,000 5,304,000

5,506,500

5,506,500 5,506,500 5,506,500 5,506,500 5,506,500 5,506,500 5,506,500

Total salaries
and wages
No. of Workers

96,00096,00096,00096,00096,00096,00038

ANNEXURE - 13
PARTICULARS OF REPAIRS AND MAINTENANCE
Particulars

Percentage

Operating Years
5

6

7

8

9

10

On Buildings

1.00%

31,66536,18938,451

38,451

38,451

38,451

38,451

38,451

38,451

38,451On Machinery and Equipment

3.00%

53,571

61,22465,05165,05165,05165,05165,05165,05165,05165,051On Other Fixed Assets

1.00%

1,330

1,520

1,615

1,615

1,615

1,615

1,615

1,615

1,615

1,615

86,566

98,933

105,116

105,116

105,116

105,116

105,116

105,116

105,116

105,116

Total

1

2

3

4

ANNEXURE - 14
PARTICULARS OF OTHER MANUFACTURING EXPENSES
Particulars

Percentage

Operating Years
5

6

7

8

9

10

Insurance on Fixed Assets

2.50%

68,52568,52568,52568,52568,52568,52568,52568,52568,52568,525

Insurance on Stocks

2.00%

15,002

16,683

17,524

17,524

17,524

17,524

17,524

17,524

17,524

17,524

Contingencies

1.00%

835

852

860

860

860

860

860

860

860

860

84,362

86,06086,90986,90986,90986,90986,90986,90986,90986,909

Total

1

2

3

4

ANNEXURE - 15
ADMINISTRATIVE OVERHEADS
Particulars

Annual overheads
1

2

3

4

5

6

7

8

9

10

Printing & Stationery

10,000

7,000

8,000

8,500

8,500

8,500

8,500

8,500

8,500

8,500

8,500

Travelling & Conveyance

20,00014,00016,00017,00017,00017,00017,00017,00017,00017,00017,000Miscellaneous Expenses

20,00014,00016,00017,00017,00017,00017,00017,00017,00017,00017,00035,00040,00042,50042,50042,50042,50042,50042,50042,50042,500

INR / unit

Total Admin. Overheads

Operating Years

Pre-Feasibility Studies for Implementation of Green Brick Production | 135

ANNEXURE - 16
WORKING CAPITAL REQUIREMENTS
Item

Stocking
Level

Operating Years(Days)
No. of Working Days in
Year

1

2

3

4

5

6

7

8

9

10

300

300

300

300

300

300

300

300

300

300

Raw Materials

21

268,569

306,936

326,120

326,120

326,120

326,120

326,120

326,120

326,120

326,120

Consumables

21

8,057

9,208

9,784

9,784

9,784

9,784

9,784

9,784

9,784

9,784

Finished Goods (FGs)

10

319,192354,963

372,848

372,848

372,848

372,848

372,848

372,848

372,848

372,848

Work-In-Progress (WIP)

15

430,910479,199503,344503,344503,344503,344503,344503,344503,344503,344

Book Debts

211,005,893

1,203,716

1,282,258

1,285,200

1,285,200

1,285,200

1,285,200

1,285,200

1,285,200

1,285,200

Expenses (Administrative 21
overheads and Utilities)

47,13853,872

57,23957,23957,23957,23957,23957,23957,23957,239Total Current Assets

2,079,759

2,407,894

2,551,592

2,554,534

2,554,534

2,554,534

2,554,534

2,554,534

2,554,534

2,554,534

191,835

219,240

232,943

232,943

232,943

232,943

232,943

232,943

232,943

232,943

1,887,924

2,188,654

2,318,650

2,321,592

2,321,592

2,321,592

2,321,592

2,321,592

2,321,592

2,321,592

Less: Creditors
Net Working Capital

15

136 | Pre-Feasibility Studies for Implementation of Green Brick Production

ANNEXURE 7 – Greening of Brick Industry in Assam |Proposal for introducing energy efficient, low carbon
burnt brick production technologies

Greening of Brick Industry in Assam
Proposal for introducing energy efficient, low carbon
burnt brick production technologies

Submitted to
Swiss Agency for Development
and Cooperation
New Delhi, India

Submitted byAssam Climate Change Management
Society (ACCMS), Govt. of Assam
Panjabari, Guwahati, Assam

Pre-Feasibility Studies for Implementation of Green Brick Production | 137

1. Introduction
The construction sector is one of the most widely recognized sectors across the globe. In
India, this sector is the second largest employer after agriculture, and is slated to grow at
6.2%10 over the next decade (2018-2027). This growth places a consequent demand forincreased building materials, especially bricks, among others such as sand, aggregates,
cement, steel, aluminium, timber, glass and tiles.
India is the second largest producer of bricks, with only China ahead of it. Its estimatedannual production of bricks is 240-260 billions11, manufactured using around 140,000 brickkilns2. However, the Indian brick sector relies majorly on technologies that are inefficient
in resource and energy, such as Fixed Chimney Bull’s Trench Kiln (FCBTK) and clamps, withminimal signs of shifting to efficient technologies. The traditional clay brick sector consumes
nearly 35-40 million tonnes2 (MT) of coal annually, emits around 66 MT2 of carbon dioxide(CO2) accounting for 5.5% of total Green House Gas (GHG) emissions from India, and depletes
approximately 500 MT2 of fertile top soil each and every year. While over the last decade
there has been a relative growth in the market for alternate building materials such as fly ash
bricks, AAC blocks, compressed earth blocks (CEB) and concrete blocks, the share is almost
negligible. In India, almost 65% of the total burnt clay brick production is from the IndoGangetic plains, with Uttar Pradesh, Bihar, West Bengal, Punjab, Haryana and Assam being
the major producers.
Out of the total CO2 emissions of the country, the state of Assam contributes around 1.6
million tons from the burnt clay brick sector. This is slated to rise considering the increased
level of construction and therefore the consumption of building materials.

2. The Brick Industry in AssamWith increasing rural affluence, demand of bricks for construction of houses in villages inIndia has gone up significantly over the last few years. Rural housing according to industry
estimates is expected to account for atleast 50% of the overall demand for bricks during 2010
and beyond, replacing traditional drivers for brick consumption i.e. infrastructure and theurban housing segment. Rural people especially in the rural parts of predominantly underdeveloped states of Bihar, Uttar Pradesh, Assam, Chattisgarh and Jharkhand are increasingly
replacing thatched mud hutments and switching over to “brick and mortar” structures.
Assam is dominated by burnt clay bricks similar to the rest of India. Presently Assam has
about 669 burnt clay brick kilns12 which produce approximately 2 billion13 fired clay bricks
annually. In manufacturing these clay bricks, approximately 5.56 million tons14 of fertile
soil is stripped off every year with an emission of 1.6 million tonnes of CO2. The high use of
agricultural soil puts an immense pressure on the agricultural activity also.
However despite a high production of burnt clay bricks, still there is a shortfall between
supply and demand. It is estimated that in the next couple of years there will be a demandof around 350 more bricks kilns in the state. To cater to this shortfall, it is obvious that there
will be new brick industries coming up in the state of Assam. The brick industry in Assam(typical to any Indian Brick Industry) is besieged with age old Bull’s Trench Kiln Technology.
Technological advances have brought out fixed chimney variant of BTK technology replacing
the movable chimneys. Demand of alternate technologies i.e. VSBK and fly ash are also
10 World Cement, India’s construction industry to grow strongly, Jonathan Rowland ,14th March 2018.<https://www.
worldcement.com/indian-subcontinent/14032018/indias-construction-industry-to-grow-strongly/ > (accessed on
25th March 2019)11 Kamyotra J S. 2016. CPCB presentation titled “Brick Kilns in India”. Presentation made at the workshop on“Roadmap for Brick Kiln Sector Challenges and Opportunities”, organized by the Centre for Science andEnvironment at New Delhi on 8 February 201612 Divisional Forest Offices, Assam
13 Average annual brick production of 1 FCBTK is 30 lakhs. Assuming all bricks kilns is functional
14 1 brick consumes 2.8kg of soil

138 | Pre-Feasibility Studies for Implementation of Green Brick Production

gaining popularity. In spite of the advances made; the brick industry in Assam still remains
one of the major polluting and resource inefficiency sectors creating a growing healthconcern among the local population. Pollution situations are aggravated especially during
the winter months with restricted wind movement. In North and Eastern Assam areas, thisfurther worsens during the winter season when thermal inversion, where cold air flowing
down from the mountains is trapped under a layer of warmer air, creates a lid, which keeps
the pollutants, sealed within the plains.
The fixed chimney brick industry in Assam has a high specific energy consumption of
1.59MJ/kg consuming around 0.4 million tonnes of coal thereby releasing around 1.2 million
tonnes of CO2 each and every year. The amount of suspended particulate matter (SPM) andparticulate matter less than 10 microns (PM10) resulting from the same are also beyond
tolerable limits higher than WHO guidelines. Use of immature, bituminous, low quality coalfrom North East India e.g. Assam, Meghalaya etc. (>1% Sulphur content) leads to high CO2
and SO2 emissions contributing to anthropogenic climate change. Particulate matters andSO2 cause serious health problems, predominantly in the respiratory system. Of late interestis the measurement of black carbon or soot also which is also considered to be a major
source of global warming.

The brick industry is an important industry in the rural economy of Assam. While there is ageographical space within which brick kiln are located to take advantage of soil, they are not
located at very close proximity of one another. Thus brick kilns in Assam can be viewed as a“regional industrial cluster” in the rural sector. It employs millions of workers, mostly migrantin nature who come with their families and works for several months from Bihar, UP andWest Bengal. There usually is no work during the rainy season, as a result of which workers
are forced to look for other jobs or return to native villages. Many of the workers belong
to the poorest sections of society and separated from whatever social and other support
structures existed in their area of origin. They are also typically isolated in their new settings.
The workers are highly vulnerable to manipulation by contractors bypassing basic labour
regulations and rights. The industry also has a high incidence of child labour which is unpaid
and exploited.

Pre-Feasibility Studies for Implementation of Green Brick Production | 139

Similarly, Assam has about 669 burnt clay brick kilns15 which produce approximately 2billion16 fired clay bricks annually. In manufacturing these clay bricks, approximately 5.56
million tons17 of fertile soil is stripped off every year with an emission of 1.6 million tonnes ofCO2. The high use of agricultural soil puts an immense pressure on the agricultural activity
also.

3. Need for improvement
The project aims to demonstrate two types of technologies:
1.

Improvement of existing practices i.e. use of internal fuel in unfired brick making

2.

Introduction of transformative technologies i.e. the Vertical Shaft Brick Kiln

Demonstration of these technologies will be implemented in a business-like manner withimproved profitability as the main target alongwith reducing emissions and improving
efficiency in resource use. Additionally coal producers will be demonstrated a solution to use
their waste materials in a profitable manner through the use of slurry in internal fuel brickmaking. The brick manufacturing community will be provided with a solution to lower theirenergy consumption. Apart from reduced energy consumption, there will be improvementon the environmental emissions from the use of internal fuel and the vertical shaft brick kiln.
These solutions will lead to improved profitability for the brick community.
It is a common perception of traditional clay brick manufacturers that new technologies
bring in a paradigm shift in approaches to brick production which will be difficult to adopt
by the existing workforce. However improved profitability and quality is assumed to be
the biggest driver of acceptance amongst new and existing entrepreneurs. A preliminary
calculation of specific energy consumption of both the technologies shows that a SEC of
0.75 MJ/kg of fired bricks can be achieved following best practices. This will result in savingsof more than 50% of the coal being consumed which will result in enhanced profitability
without any degradation in the property of the fired product.
The most important parameter in getting a good quality product is uniform mixing of soil
and additives. This can be achieved only through mechanized mixing which is supposed to
improve the quality of the fired brick by achieving increased densification. If all the 700 FCK
units adopt the best practices, it is expected to result in:•

Saving of 0.2 million tonnes of coal per year•

Profitability of around INR 1.6 billion annually from savings of coal•

Saving of 0.6 million tonnes of CO2 each and every year

4. Technologies to be implemented
The project aims to demonstrate two types of technologies:
1.

Improvement of existing practices i.e. use of internal fuel in unfired brick making

2.

Introduction of transformative technologies i.e. the Vertical Shaft Brick Kiln

A brief description of these technologies is given below:

15 Divisional Forest Offices, Assam
16 Average annual brick production of 1 FCBTK is 30 lakhs. Assuming all bricks kilns is functional
17 1 brick consumes 2.8kg of soil

140 | Pre-Feasibility Studies for Implementation of Green Brick Production

1. Improvement of existing practices i.e. use of internal fuel in unfired
brick making
This technology will demonstrate the use of internal fuel in unfired brick making. The internalfuel to be used will be coal dust, boiler ash, rice husk ash or any form of carbonaceous
waste materials. These waste materials will be ground in specified sized in a coal crusher orpulveriser and added to the soil during processing. The processing of the soil has to be done
through mechanized means i.e. pugmill or any other process to ensure uniformity in mixing.
Once the bricks are dried, then the normal process of loading, firing and unloading will
follow. The most important aspect of this technology is that the capital cost requirement isextremely low and no change in existing brick making process needs to be followed.

2. Introduction of transformative technologies i.e. the Vertical Shaft
Brick Kiln
Vertical Shaft Brick Kiln (VSBK)
technology is an energy efficienttechnology for firing clay bricks. It isparticularly suited to the needs of brickproduction in developing countries –which is small scale and decentralized
type. The evolution and initialdevelopment of VSBK technology
took place in rural China. The firstversion of VSBK in China originatedfrom traditional updraft intermittent
kiln during 1960’s. During 70’s, the kiln
became popular in several provincesof China. In 1985, Chinese government commissioned the Energy Research Institute of theHenan Academy of Sciences at Zhengzhou (Henan province), to study the kiln to improvethe energy efficiency. The institute came up with an improved design of VSBK in 1988 which
had a higher shaft height and provisions for a pair of chimneys. About 50,000 VSBKs were
estimated to be operating in China during 1996.
Various attempts to disseminate VSBK technology outside China started in early 1990’s.
It was demonstrated in several Asian countries such as Nepal, Afghanistan, Pakistan and
Bangladesh. However no appreciable success was reported in the external domain to
document factors of success.
VSBK in India was launched in 1995 by Swiss Agency for Development & Cooperation (SDC)
as a project on introducing sustainable production systems for building materials.
The factors that has contributed
towards its successful adoption
in India was its suitability fordecentralized production systems andpositioning as a means of improving
the product quality thus ensuring
higher returns of investment. Simple
mechanization was implemented
for unfired brick making, material
handling,
transportation
andextrusion of unfired bricks. Internalfuel in the form of coal, biomass and

Pre-Feasibility Studies for Implementation of Green Brick Production | 141

sawdust is added during the moulding of unfired bricks – this creates highly favourable
conditions for short cycle firing.
Thus within a span of 5 years (2000 – 2005) more than 100 VSBK’s were established in acommercial mode. The qualities of bricks were accepted in the market at a premium rate.
Most of the entrepreneurs were satisfied with the flexibility and performance of the kiln.
This was reiterated by the increasing investment in selective mechanization and capacity
augmentation. After the commercial success of VSBK in India as a viable alternative to
traditional brick making with huge potential to energy and environment savings, VSBK
technology was reopened in Nepal.

Kiln description and working principle
VSBK has vertical shaft of rectangular or
square cross-section. The gap between
shaft wall and outer kiln wall is filled withinsulating materials – broken bricks
and burnt coal ash. The kiln works asa counter-current heat exchanger, withheat transfer taking place between
the air moving up (continuous flow)
and bricks moving down (intermittent
movement). Unfired bricks are loaded
in batches from kiln top. Bricks move
down the shaft through brick preheating, firing and cooling zones and unloaded from bottom. The combustion of coal(added along with bricks at the top) takes place in the middle of the shaft. Combustion air
enters shaft from bottom, gets preheated by hot fired bricks in the lower portion of the shaft
before reaching the combustion zone. Hot combustion gases preheat unfired bricks in upper
portion of the shaft before exiting from the kiln through shaft or chimney.
The brick setting in kiln is kept on support bars at bottom of the shaft. Unloading of bricks
is done from bottom of the shaft using a trolley. The trolley is lifted (using single screw
mechanism) till the iron beams placed on the trolley touches the bottom of the brick setting
and the weight of bricks is transferred on to the trolley. The freed support bars are taken out.
The trolley is then loweredby one batch (equivalent to
4 layers of bricks) – support
bars are again put in placethrough the holes provided
in the brick setting forthe purpose. With slightdownward movement, theweight of the brick setting
is transferred to support
bars. The trolley (with one
batch of fired bricks onit) is further lowered till it
touches ground level andthen pulled out of the kiln
on a pair of rails provided
for the purpose. At every
2 - 3 hours, one batch of

142 | Pre-Feasibility Studies for Implementation of Green Brick Production

fired bricks is unloaded at bottom and a batch of fresh unfired bricks is loaded at the top
simultaneously. At any given time, there are typically 11 to 12 batches in the kiln dependingon the unfired brick quality.
Two chimneys located diagonally opposite to each other in the shaft remove flue gases fromthe kiln. A lid is also provided on the shaft top which is kept closed during normal operation.
Flue gases are directed to pass through chimney thus not polluting working area on the kiln
top. The provision of shaft lid, better ventilation of working area on kiln top and higher andbigger chimneys are some of the highlights of VSBK kiln and its related process.
The heating cycle for the unfired bricks is raw material specific (pre-heating, vitrification andcooling down) and is normally completed within 24-30 hours. A batch of bricks is loaded
and unloaded every 2-3 hours; requiring round the clock operations and supervision. Thisrequires special skills and the firing operator needs to maintain a correct balance between:•

Energy - Controlled by amount of coal feeding•

Airflow - Controlled by stacking density and damper position•

Unloading speed - Controlled by the operator

Comparison of BTK and VSBK operation
Both the types of kilns are continuous updraft kiln with a central chimney for exhaust of fluegases. However the basic differences in both the types of firing are:•

In VSBK to start firing only
about 4000 to 5000 bricks areneeded (depending upon theshaft cross section). In BTK
firing can only start after at
least 50 to 60 lines are filled up.
The above process requires
approximately 2 to 3 lakhs of
unfired bricks. Thus VSBK is a
low capital investment firing.

•

In VSBK for initial firing small
fireboxes are made at thebottom. For initial firing fromthe bottom only about 100 kg of dry firewood is required to start the fire. No firewood
is required after initial burning. In BTK the fireboxes are much wider and larger in size.
Large quantities of firewood is required alongwith other flammable materials like saw
dust, rubber tyres etc.

Pre-Feasibility Studies for Implementation of Green Brick Production | 143

•In VSBK the fire wood is burnt for an initial period of 3 to 4 hours for firing initialization
whereas in BTK a minimum of 16 to 20 hours are required for the same result.

•

In VSBK after initial firing stable production is achieved within 3 to 4 days by which
saleable bricks are produced. In BTK for production of suitable saleable bricks agestation period of at least 15 to 20 days are required.

Basic advantages of VSBK over conventional BTK technology
High energy efficiency
The VSBK technology economizes on fuel costs, with savings of between 30 to 50% whencompared with other common brick firing technologies such as clamps or Bull’s trench kiln
with movable chimneys.
Environment friendly operations
The construction of a VSBK requires very little land. The building of multiple shaft production
units further enhances the ratio of land use to production output. As a VSBK can only be firedwith coal (or with coal dust), deforestation of rural areas can be controlled. Additionally, if a
VSBK is operated as per recommended conditions, emissions are reduced by approximately
90% compared to common traditional brick firing technologies.
Economically viable
Brick production using VSBK technology is a profitable business and the overall initialinvestment is low (considering investment in permanent land). Since in a VSBK the fired
bricks are produced in 24 hours so the working capital required is very less.
Uniform quality of production
Unlike other brick firing technologies where a uniform quality of fired bricks is not possible
due to heat losses, in VSBK the batches of fired bricks produced are 95% uniform in quality
segregated into a single class. Compared to the BTK where 2nd and 3rd grade bricks areproduced in significant quantities, a VSBK produces mostly 1st grade bricks. Breakage andwastage can be limited to even less than 5% through stable operation of the VSBK andquality unfired brick making.
Round the year production
The VSBK can be operated all the year round and even during monsoon time subject toavailability of dried unfired bricks. Weather factors have only a minor influence because aroof protects the kiln.
Consistent quality
VSBK produces high quality
bricks if proper firing practices
are followed. In fact, the products
are even superior to those ofexisting rural brick production
technologies (traditional and BTK
firing technologies). VSBK fired
bricks show a fine, deep red colour
and have a good, metallic ringdepending upon the soil quality.
A compressive strength of upto
200 kg/cm2 can be achieved using
good quality soils.

144 | Pre-Feasibility Studies for Implementation of Green Brick Production

5. Goal
The goal of this project is to create awareness, sensitize and build capacity of key stakeholders
towards large scale dissemination of cleaner technologies and practices in the brick sector
in Assam.

6. Objectives
The specific objectives of the proposed project are:•Sensitization and capacity building of diverse stakeholders to secure interest and futurecontribution to a large brick sector transformation initiative•

Demonstrate potential benefits of Vertical Shaft Brick Kiln and internal fuel technology
and establish a clear baseline in terms of energy efficiency, environmental emissions
and profitability•

Make potential benefits visible to key stakeholders through demonstration andknowledge products.

7. Dissemination conducted
Assam Climate Change Management Society (ACCMS), Govt. of Assam and Climate Change
Cell, Assam supported by Department of Science and Technology (DST), Govt. of India
organized two workshops to create awareness on the current status of brick production in
Assam and future scenarios for fired brick production and to build capacity on the unfired
brick kiln technologies. The brick manufacturers, brick users, technology providers, financial
institutions and knowledge partners participated in the workshops organized at Bongaigaon
and Nagaon district on 4th October, 2021 and 5th October, 2021 respectively.
The primary objectives of the workshops were as follows:•

Aware the brick kiln owners on the current status of brick kiln industry and its impact onenvironment.

•

Make the participants familiar with different methods/techniques of upgradation inexisting brick production system.

•

Knowledge building of the participants on improvement and process optimization inexisting brick firing technologies.

•

Make the entrepreneurs aware on transformative new technologies like Vertical shaft
brick kilns (VSBK), Fly ash bricks, and compressed earth blocks etc.

Despite inclement weather conditions, there were more than 200 entrepreneurs attending
the Workshops. Most of them were from the existing burnt clay brick industries. Most
workshops meetings and discussions confirmed the interest of more than 50 entrepreneursin VSBK and use of internal fuel also. They are ready to provide land and also invest into thetechnology of assurances of technology transfer can be given.
It was recommended that in the areas of Dhubri, Bongaigaon and Nagaon immediate
interventions be made to keep up with the interest shown by entrepreneurs.

Pre-Feasibility Studies for Implementation of Green Brick Production | 145

8. Work plan and methodology
The proposed project will be implemented in two phases:

Phase 1 (June 2021 – August 2021)
Knowledge building initiatives
1.

Manuals for technology transfer and dissemination

These manuals are proposed in the draft stage since they will be implemented and verified
during the implementation phase. With assessment and required modifications they will
be finalized in Phase 2. The documents proposed in this Phase will be key documents intraining and capacity building of personnel’s in Assam. They will be developed based on thecapacities and knowledge developed through more than 2 decades of experience. However
there will be a requirement of comprehensive modification and adaptation as per Assam
conditions. After adapting and modification as per Assam conditions, required testing will
be done in Phase 2 where the final document will be prepared.

Phase 2 (July 2021 – December 2022) Concurrent with Phase 1
Pilot initiatives on introduction of new technology:
1.

Introduction of VSBK technology in 2 selected areas of Assam

2.

Demonstration of internal fuel technology in existing FC BTK unit in Assam

3.

Operation and fine tuning of quality as per local demand and conditions including
profitability analysis

Capacity building initiatives:•

Training and capacity building of master masons, machine operators and firemen in
Vertical Shaft Brick Kiln and Internal fuel Technology•

Training and capacity building of local resource organization, for enabling adoption ofcleaner technologies and practices in the brick sector.

•

Build visibility and capacity of the key stakeholders including the brick manufacturers by
information dissemination through workshops and knowledge management productsThis phase will primary focus on construction and operation of a pilot VSBK in association with
TARA. Preliminary groundwork and consultations with TARA have resulted in identificationof 3 district as the first intervention area. These are Silchar, Nagaon and Dhubri. This has
been based on the potential of maximum impact creation since the traditional practicesof brick making are not very resourceful. Thus successful demonstration of an energy andenvironment efficient technology amongst the brick entrepreneurs and regulatory agencies
will increase the basket of choices for technology shift. Capacities will also be created
towards enabling large scale dissemination.

9. Outputs
Phase 1•VSBK Technology package•

Internal fuel technology package

All the packages will be in English and in the draft stage. During the Phase 2 they will be
implemented and further refined and adapted to suit Assam conditions. During Phase 2 they
will be finalized in both English and local (Assamese) language to suit local needs.
146 | Pre-Feasibility Studies for Implementation of Green Brick Production

Phase 2•

2 VSBK constructed and under operation in Assam•

1 Internal fuel technology demonstrated in Assam•

80 workers trained in various operations•

Report of energy, and environment monitoring•

Economic analysis and business package

BUDGET HEADS
S.no

Budget HeadAmount (INR)

1

Personnel Costs

7,968,000

2Travel3,420,000

3

Capital Costs - Equipment

8,200,000

4

Other Direct Costs

5,900,000

5Institutional Support Costs (15%)

3,860,700

6

GRAND TOTAL

29,348,700

Pre-Feasibility Studies for Implementation of Green Brick Production | 147

ANNEXURE 8 – Brick Lab Testing Reports and Soil
Testing Reports

148 | Pre-Feasibility Studies for Implementation of Green Brick ProductionPre-Feasibility Studies for Implementation of Green Brick Production | 149

150 | Pre-Feasibility Studies for Implementation of Green Brick ProductionPre-Feasibility Studies for Implementation of Green Brick Production | 151

152 | Pre-Feasibility Studies for Implementation of Green Brick ProductionPre-Feasibility Studies for Implementation of Green Brick Production | 153

154 | Pre-Feasibility Studies for Implementation of Green Brick Production

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified
GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

Issue No. BEE/BRICK/
Client :Date: 20/11/2020

Society for Technology and Action for Rural Advancement
B-32, TARA Crescent, Qutub Institutional Area
New Delhi, India-110016

Name of Work : Testing of Brick

SAMPLE DETAILS OF BRICK
Brand - Rahul
Date of testing - 18.11.2020 to 20.11.2020

Item - Brick samples
Date of sampling - 18.11.2020
Source :Supplied by Client
Notes :

1. This report can neither be used as an evidence in the court of law, nor it can be produced in part or
full in any media without prior permission.
2. The result listed refer only to the tested sample and applicable parameters.
3. Perishable samples are destroyed after testing; requested samples are returned back to the customer.
4. Sample(s) not drawn by us, unless otherwise mentioned.
Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

Pre-Feasibility Studies for Implementation of Green Brick Production | 155

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified
GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

2 Nos. of bricks are selected at random from the lot for determining compressive strength and 2 Nos. ofbricks are selected at random from the lot for water absorption test.

Sl. No.

Dry Weightin kg

SoakedWeight in kg

Size in cm

Crushing
strengthkg/cm2% of water
absorption

Sample No.I

3.298

3.526

22.7 x 11 x 6.5

105.52

6.91

Sample No.II

3.302

3.533

22.8 x 11.1 x 6.5

101.88

6.99

Average of crushing strength :Average of water absorption :Shape:103.7 kg/cm2
6.95 %The brick was averagely rectangular with sharp edges.

Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

156 | Pre-Feasibility Studies for Implementation of Green Brick Production

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified

GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

Issue No. BEE/BRICK/
Client :Date: 20/11/2020

Society for Technology and Action for Rural Advancement
B-32, TARA Crescent, Qutub Institutional Area
New Delhi, India-110016

Name of Work : Testing of Brick

SAMPLE DETAILS OF BRICK
Brand - A. Tara
Date of testing - 18.11.2020 to 20.11.2020

Item - Brick samples
Date of sampling - 18.11.2020
Source :Supplied by Client
Notes :

1. This report can neither be used as an evidence in the court of law, nor it can be produced in part or
full in any media without prior permission.
2. The result listed refer only to the tested sample and applicable parameters.
3. Perishable samples are destroyed after testing; requested samples are returned back to the customer.
4. Sample(s) not drawn by us, unless otherwise mentioned.
Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

Pre-Feasibility Studies for Implementation of Green Brick Production | 157

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified
GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

2 Nos. of bricks are selected at random from the lot for determining compressive strength and 2 Nos. ofbricks are selected at random from the lot for water absorption test.

Sl. No.

Dry Weightin kg

SoakedWeight in kg

Size in cm

Crushing
strengthkg/cm2% of water
absorption

Sample No.I

3.464

3.712

23.8 x 11.9 x 6.8

89.58

7.15

Sample No.II

3.496

3.781

23.8 x 12 x 6.8

91.63

8.15

Average of crushing strength :Average of water absorption :Shape:90.6 kg/cm2
7.65 %The brick was averagely rectangular with sharp edges.

Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

158 | Pre-Feasibility Studies for Implementation of Green Brick Production

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified

GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

Issue No. BEE/BRICK/
Client :Date: 20/11/2020

Society for Technology and Action for Rural Advancement
B-32, TARA Crescent, Qutub Institutional Area
New Delhi, India-110016

Name of Work : Testing of Brick

SAMPLE DETAILS OF BRICK
Brand - Nokia
Date of testing - 18.11.2020 to 20.11.2020

Item - Brick samples
Date of sampling - 18.11.2020
Source :Supplied by Client
Notes :

1. This report can neither be used as an evidence in the court of law, nor it can be produced in part or
full in any media without prior permission.
2. The result listed refer only to the tested sample and applicable parameters.
3. Perishable samples are destroyed after testing; requested samples are returned back to the customer.
4. Sample(s) not drawn by us, unless otherwise mentioned.
Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

Pre-Feasibility Studies for Implementation of Green Brick Production | 159

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified
GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

2 Nos. of bricks are selected at random from the lot for determining compressive strength and 2 Nos. ofbricks are selected at random from the lot for water absorption test.

Sl. No.

Dry Weightin kg

SoakedWeight in kg

Size in cm

Crushing
strengthkg/cm2% of water
absorption

Sample No.I

2.855

3.247

22.9 x 11.1 x 6.4

72.64

13.73

Sample No.II

2.832

3.288

22.9 x 11.2 x 6.3

70.19

16.10

Average of crushing strength :Average of water absorption :Shape:71.42 kg/cm2
14.92 %The brick was averagely rectangular with rough edges.

Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

160 | Pre-Feasibility Studies for Implementation of Green Brick Production

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified
GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

Issue No. BEE/BRICK/
Client :Date: 20/11/2020

Society for Technology and Action for Rural Advancement
B-32, TARA Crescent, Qutub Institutional Area
New Delhi, India-110016

Name of Work : Testing of Brick

SAMPLE DETAILS OF BRICK
Brand - 7 Star
Date of testing - 18.11.2020 to 20.11.2020

Item - Brick samples
Date of sampling - 18.11.2020
Source :Supplied by Client
Notes :
1.

This report can neither be used as an evidence in the court of law, nor it can be produced in part or
full in any media without prior permission.
2. The result listed refer only to the tested sample and applicable parameters.
3. Perishable samples are destroyed after testing; requested samples are returned back to the customer.
4. Sample(s) not drawn by us, unless otherwise mentioned.
Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

Pre-Feasibility Studies for Implementation of Green Brick Production | 161

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified
GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

2 Nos. of bricks are selected at random from the lot for determining compressive strength and 2 Nos. ofbricks are selected at random from the lot for water absorption test.

Sl. No.

Dry Weightin kg

SoakedWeight in kg

Size in cm

Crushing
strengthkg/cm2% of water
absorption

Sample No.I

2.859

3.206

22.2 x 11.3 x 6.6

130.15

12.13

Sample No.II

2.846

3.221

22.3 x 11.2 x 6.5

132.60

13.17

Average of crushing strength :Average of water absorption :Shape:131.38 kg/cm2
12.65 %The brick was truly rectangular with sharp edges.

Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

162 | Pre-Feasibility Studies for Implementation of Green Brick Production

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified

GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

Issue No. BEE/BRICK/
Client :Date: 20/11/2020

Society for Technology and Action for Rural Advancement
B-32, TARA Crescent, Qutub Institutional Area
New Delhi, India-110016

Name of Work : Testing of Brick

SAMPLE DETAILS OF BRICK
Brand - Lucky
Date of testing - 18.11.2020 to 20.11.2020

Item - Brick samples
Date of sampling - 18.11.2020
Source :Supplied by Client
Notes :

1. This report can neither be used as an evidence in the court of law, nor it can be produced in part or
full in any media without prior permission.
2. The result listed refer only to the tested sample and applicable parameters.
3. Perishable samples are destroyed after testing; requested samples are returned back to the customer.
4. Sample(s) not drawn by us, unless otherwise mentioned.
Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

Pre-Feasibility Studies for Implementation of Green Brick Production | 163

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified

GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

2 Nos. of bricks are selected at random from the lot for determining compressive strength and 2 Nos. ofbricks are selected at random from the lot for water absorption test.

Sl. No.

Dry Weightin kg

SoakedWeight in kg

Size in cm

Crushing
strengthkg/cm2% of water
absorption

Sample No.I

2.853

3.487

23.6 x 12.1 x 6.4

55.67

22.22

Sample No.II

2.866

3.485

23.5 x 12 x 6.5

58.32

21.59

Average of crushing strength :Average of water absorption :Shape:56.99 kg/cm2
21.91 %The brick was irregular in shape and have broken edges.

Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

164 | Pre-Feasibility Studies for Implementation of Green Brick Production

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified

GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

Issue No. BEE/BRICK/
Client :Date: 23/11/2020

Society for Technology and Action for Rural Advancement
B-32, TARA Crescent, Qutub Institutional Area
New Delhi, India-110016

Name of Work : Testing of Brick

SAMPLE DETAILS OF BRICK
Brand - PRINCE
Date of testing - 19.11.2020 to 21.11.2020

Item - Brick samples
Date of sampling - 19.11.2020
Source :Supplied by Client
Notes :

1. This report can neither be used as an evidence in the court of law, nor it can be produced in part or
full in any media without prior permission.
2. The result listed refer only to the tested sample and applicable parameters.
3. Perishable samples are destroyed after testing; requested samples are returned back to the customer.
4. Sample(s) not drawn by us, unless otherwise mentioned.
Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

Pre-Feasibility Studies for Implementation of Green Brick Production | 165

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified

GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

3 Nos. of bricks are selected at random from the lot for determining compressive strength and 3 Nos. ofbricks are selected at random from the lot for water absorption test.

Sl. No.

Dry Weightin kg

SoakedWeight in kg

Size in cm

Crushing
strengthkg/cm2% of water
absorption

Sample No.I

2.944

3.433

23.1 x 11.4 x 6.8

67.58

16.61

Sample No.II

2.956

3.426

23.2 x 11.5 x 6.7

71.09

15.89

Sample No.III

2.942

3.444

23.0 x 11.4 x 6.7

68.25

17.06

Average of crushing strength :Average of water absorption :Shape:68.97 kg/cm2
16.52 %The brick was averagely rectangular with rough edges.

Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

166 | Pre-Feasibility Studies for Implementation of Green Brick Production

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified

GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

Issue No. BEE/BRICK/
Client :Date: 23/11/2020

Society for Technology and Action for Rural Advancement
B-32, TARA Crescent, Qutub Institutional Area
New Delhi, India-110016

Name of Work : Testing of Brick

SAMPLE DETAILS OF BRICK
Brand - SINGH
Date of testing - 19.11.2020 to 21.11.2020

Item - Brick samples
Date of sampling - 19.11.2020
Source :Supplied by Client
Notes :

1. This report can neither be used as an evidence in the court of law, nor it can be produced in part or
full in any media without prior permission.
2. The result listed refer only to the tested sample and applicable parameters.
3. Perishable samples are destroyed after testing; requested samples are returned back to the customer.
4. Sample(s) not drawn by us, unless otherwise mentioned.
Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

Pre-Feasibility Studies for Implementation of Green Brick Production | 167

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified
GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

3 Nos. of bricks are selected at random from the lot for determining compressive strength and 3 Nos. ofbricks are selected at random from the lot for water absorption test.

Sl. No.

Dry Weightin kg

SoakedWeight in kg

Size in cm

Crushing
strengthkg/cm2% of water
absorption

Sample No.I

2.627

3.010

22.5 x 10.4 x 6.4

137.62

14.57

Sample No.II

2.646

2.998

22.5 x 10.6 x 6.4

128.7813.30

Sample No.III

2.638

3.022

22.3 x 10.4 x 6.5

143.83

14.55

Average of crushing strength :Average of water absorption :Shape:136.74 kg/cm2
14.14 %The brick was truly rectangular with sharp edges.

Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

168 | Pre-Feasibility Studies for Implementation of Green Brick Production

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified

GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

Issue No. BEE/BRICK/
Client :Date: 23/11/2020

Society for Technology and Action for Rural Advancement
B-32, TARA Crescent, Qutub Institutional Area
New Delhi, India-110016

Name of Work : Testing of Brick

SAMPLE DETAILS OF BRICK
Brand - ANJANA
Date of testing - 19.11.2020 to 21.11.2020

Item - Brick samples
Date of sampling - 19.11.2020
Source :Supplied by Client
Notes :

1. This report can neither be used as an evidence in the court of law, nor it can be produced in part or
full in any media without prior permission.
2. The result listed refer only to the tested sample and applicable parameters.
3. Perishable samples are destroyed after testing; requested samples are returned back to the customer.
4. Sample(s) not drawn by us, unless otherwise mentioned.
Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

Pre-Feasibility Studies for Implementation of Green Brick Production | 169

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified
GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

3 Nos. of bricks are selected at random from the lot for determining compressive strength and 3 Nos. ofbricks are selected at random from the lot for water absorption test.

Sl. No.

Dry Weightin kg

SoakedWeight in kg

Size in cm

Crushing
strengthkg/cm2% of water
absorption

Sample No.I

2.602

3.025

22.6 x 10.9 x 6.5

132.7916.25

Sample No.II

2.643

3.001

22.5 x 11.1 x 6.5

128.08

13.54

Sample No.III

2.625

3.011

22.6 x 10.8 x 6.7

137.31

14.70

Average of crushing strength :Average of water absorption :Shape:132.72 kg/cm2
14.76 %The brick was averagely rectangular with rough edges.

Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

170 | Pre-Feasibility Studies for Implementation of Green Brick Production

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified

GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

Issue No. BEE/AAC-B/
Client :Date: 23/11/2020

Society for Technology and Action for Rural Advancement
B-32, TARA Crescent, Qutub Institutional Area
New Delhi, India-110016

Name of Work : Testing of Brick

SAMPLE DETAILS OF AAC BLOCK
Item – AAC Block samples
Date of sampling - 18.11.2020
Source :Supplied by Client

Brand - Unknown
Date of testing - 19.11.2020 to 21.11.2020

Notes :
1. This report can neither be used as an evidence in the court of law, nor it can be produced in part or
full in any media without prior permission.
2. The result listed refer only to the tested sample and applicable parameters.
3. Perishable samples are destroyed after testing; requested samples are returned back to the customer.
4. Sample(s) not drawn by us, unless otherwise mentioned.
Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

Pre-Feasibility Studies for Implementation of Green Brick Production | 171

BUILDEAST ENGINEERING
Material Testing Lab | Soil Investigation | Structural DesignStandard ISO/IEC 17025:2017 ISO 9000-2015Certified
GSTIN 18AAVFB4670J1ZU -MSME UAM No: AS05D0000514

3 Nos. of blocks are selected at random from the lot for determining compressive strength and 3 Nos. ofblocks are selected at random from the lot for water absorption test.

Sl. No.

Dry Weightin kg

SoakedWeight in kg

Size in cm

Crushing
strengthkg/cm2% of water
absorption

Sample No.I

5.653

7.377

59.4 x 19.2 x 7.3

31.61

30.49

Sample No.II

5.644

7.390

59.9 x 19.1 x 7.4

24.58

30.93

Sample No.III

5.668

7.426

59.7 x 19.3 x 7.3

29.32

31.01

Average of crushing strength :Average of water absorption :Shape:28.50 kg/cm2
30.81 %The block was truly rectangular with sharp edges.

Quality Manager

Build East Engineering

Address- AK Lane Opp. Vivekananda Co-Operative
Meherpur, Silchar–15, Assam
E-mail- buildeastengg@gmail.com
Mob: +91- 6003633880, +91-9402087771

172 | Pre-Feasibility Studies for Implementation of Green Brick ProductionPre-Feasibility Studies for Implementation of Green Brick Production | 173

174 | Pre-Feasibility Studies for Implementation of Green Brick ProductionPre-Feasibility Studies for Implementation of Green Brick Production | 175

Commander Sample ID (Coupled TwoTheta/Theta)

Commander Sample ID (Coupled TwoTheta/Theta)

176 | Pre-Feasibility Studies for Implementation of Green Brick Production

Commander Sample ID (Coupled TwoTheta/Theta)

Commander Sample ID (Coupled TwoTheta/Theta)

Pre-Feasibility Studies for Implementation of Green Brick Production | 177

ANNEXURE 9 – Ministry of Environment, Forest andClimate Change Notification, 2022
REGD. No. D. L.-33004/99
xxxGIDExxx
CG-DL-E-22022022-233662

EXTRAORDINARYPART II—Section 3—Sub-section (i)PUBLISHED BY AUTHORITY
No. 140] NEW DELHI, TUESDAY, FEBRUARY 22, 2022/PHALGUNA 3, 1943

MINISTRY OF ENVIRONMENT, FOREST AND CLIMATE CHANGENOTIFICATIONNew Delhi, the 22nd February, 2022
G.S.R. 143(E).—In exercise of the powers conferred by sections 6 and 25 of the Environment(Protection) Act, 1986 (29 of 1986), the Central Government hereby makes the following rules further toamend the Environment (Protection) Rules, 1986, namely:—
1. Short Title and commencement: (1) These rules may be called the Environment (Protection) Amendment Rules,
2022. (2) They shall come into force on the date of their publication in the
Official Gazette.
2. In the Environment (Protection) Rules, 1986, in the SCHEDULE-I, for entry at Sl. No. 74, thefollowing entry shall be substituted, namely: “74

Brick
Kilns

Particulate matter in stack emission

250 mg/Nm3

Minimum stack height (Vertical Shaft

14 m (at least 7.5m
from loading platform)
16 m (at least 8.5m
from loading platform)

Brick Kilns) - Kiln capacity less than
30,000 bricks per day- Kiln capacity equal or more than 30,000 bricks perday
Minimum stack height (Other than Vertical Shaft
Brick Kilns) - Kiln capacity less than 30,000 bricks
per day- Kiln capacity equal or more than 30,000 bricks perday

178 | Pre-Feasibility Studies for Implementation of Green Brick Production

24 m
27 m

Notes :1.

All new brick kilns shall be allowed only with zig-zag technology or vertical shaft or use of Piped
Natural Gas as fuel in brick making and shall comply with these standards as stipulated in thisnotification.

2.

The existing brick kilns which are not following zig-zag technology or vertical shaft or use Piped
Natural Gas as fuel in brick making shall be converted to zig-zag technology or vertical shaft or use
Piped Natural Gas as fuel in brick making within a period of (a) one year in case of kilns locatedwithin ten kilometre radius of non-attainment cities as defined by Central Pollution Control
Board (b) two years for other areas. Further, in cases where Central Pollution Control Board/State
Pollution Control Boards/Pollution Control Committees have separately laid down timelines forconversion, such orders shall prevail.

3.

All brick kilns shall use only approved fuel such as Piped Natural Gas, coal, fire wood and/or
agricultural residues. Use of pet coke, tyres, plastic, hazardous waste shall not be allowed in brickkilns.

4.

Brick kilns shall construct permanent facilities (port hole and platform) as per the norms ordesign laid down by the Central Pollution Control Board for monitoring of emissions.

5.

Particulate Matter (PM) results shall be normalised at 4% CO2 as below:
PM (normalised) = (PM (measured)x 4%)/ (% of CO2 measured in stack), no normalisation in case
CO2 measured ≥ 4%. Stack height (in metre) shall also be calculated by formula H=14Q0.3 (where Q
is SO2 emission rate in kg/hr), and the maximum of two shall apply.

4 THE GAZETTE OF INDIA : EXTRAORDINARY [PART II—SEC. 3(i)]6.

Brick kilns should be established at a minimum distance of 0.8 kilometre from habitation andfruit orchards. State Pollution Control Boards/Pollution Control Committees may make siting
criteria stringent considering proximity to habitation, population density, water bodies, sensitive
receptors, etc.

7.

Brick kilns should be established at a minimum distance of one kilometre from an existing brickkiln to avoid clustering of kilns in an area.

8.

Brick kilns shall follow process emission/fugitive dust emission control guidelines as prescribedby concerned State Pollution Control Boards/Pollution Control Committees.

9.

The ash generated in the brick kilns shall be fully utilised in-house in brick making.

10. All necessary approvals from the concerned authorities including the mining department of theconcerned State or Union Territory shall be obtained for extracting the soil to be used for brickmaking in the brick kiln.
11. The brick kiln owners shall ensure that the road utilised for transporting raw materials or bricks
are paved roads.
12. Vehicles shall be covered during transportation of raw material/bricks”.
[F. No. Q-15017/35/2007-CPW]
NARESH PAL GANGAWAR, Addl. Secy.
Note :The principle rules were published in the Gazette of India, Extraordinary, Part II, Section 3,
Subsection (i) vide number S.O. 844(E), dated the 19th November, 1986 and lastly amended vide
number G.S.R. 724(E), dated the 04th October, 2021.

Uploaded by Dte. of Printing at Government of India Press, Ring Road, Mayapuri, New
Delhi-110064 and Published by the Controller of Publications, Delhi-110054.

Pre-Feasibility Studies for Implementation of Green Brick Production | 179

180 | Pre-Feasibility Studies for Implementation of Green Brick ProductionPre-Feasibility Studies for Implementation of Green Brick Production | 181

Assam Climate Change Management Society (ACCMS) - a
Special Purpose Vehicle (SPV) was created in 2018 under
the chairmanship of the Hon’ble Chief Minister, Governmentof Assam. Assam Climate Change Management Society was
registered under the Societies Registration Act XXI of 1860 on 15th
October, 2018. ACCMS coordinates all issues related to climatechange and implements the Assam State Action Plan on Climate
Change (ASAPCC), aligning state priorities and different national
and international goals such as Sustainable Development Goals(SDGs), Nationally Determined Contributions (NDCs), Reducing
Emissions from Deforestation and Forest Degradation (REDD+)
and others in different sectors.

3rd Floor, Aranya Bhawan, Panjabari
Guwahati-37, Assam
Email: accmsociety@gmail.com
www.accms.org.in