Chapter 5: Incineration and Open Burning of Waste

CHAPTER 5

INCINERATION AND OPEN BURNING
OF WASTE

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Authors
Sirintornthep Towprayoon (Thailand), Seungdo Kim (Republic of Korea), Eui-Chan Jeon (Republic of Korea),Tomonori Ishigaki (Japan), Seini Nouhou Amadou (Niger)

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Chapter 5: Incineration and Open Burning of Waste

Contents

5

Incineration and Open Burning of Waste ..................................................................................................... 5.5
5.1

Introduction ......................................................................................................................................... 5.5

5.2

Methodological issues ......................................................................................................................... 5.9

5.2.1

Choice of method for estimating CO 2 emissions .......................................................................... 5.10

5.2.2

Choice of method for estimating CH 4 emissions .......................................................................... 5.11

5.2.3

Choice of method for estimating N 2 O emissions .......................................................................... 5.11

5.3

Choice of activity data ....................................................................................................................... 5.11

5.3.1

Amount of waste incinerated......................................................................................................... 5.11

5.3.2

Amount of waste open-burned ...................................................................................................... 5.11

5.3.3

Dry matter content......................................................................................................................... 5.11

5.4

Choice of emission factors ................................................................................................................ 5.12

5.4.1

CO 2 emission factors .................................................................................................................... 5.12

5.4.2

CH 4 emission factors .................................................................................................................... 5.13

5.4.3

N 2 O emission factors .................................................................................................................... 5.15

5.5

Completeness .................................................................................................................................... 5.16

5.6

Developing a consistent time series................................................................................................... 5.16

5.7

Uncertainty assessment ..................................................................................................................... 5.17

5.7.1

Emission factor uncertainties ........................................................................................................ 5.17

5.7.2

Activity data uncertainties ............................................................................................................. 5.17

5.8

QA/QC, Reporting and Documentation ............................................................................................ 5.17

5.8.1

Inventory Quality Assurance/Quality Control (QA/QC)............................................................... 5.17

5.8.2

Reporting and Documentation ...................................................................................................... 5.17

References .......................................................................................................................................................... 5.18

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TablesTable 5.2 (Updated)

Default data for CO 2 emission factors for incineration and open burning of waste ...... 5.12

Table 5.3

CH 4 emission factors for incineration of MSW ............................................................. 5.13

Table 5.3a (New)CH 4 emission factors for pyrolysis-melting and gasification-melting plant of MSW ... 5.14

Table 5.4

N 2 O emission factors for incineration of MSW............................................................. 5.16

Table 5.4a (New)N 2 O emission factors for pyrolysis-melting and gasification-melting plant of MSW ... 5.16

Boxes
Box 5.0a (New)

Pyrolysis .......................................................................................................................... 5.6

Box 5.0b (New)Gasification ...................................................................................................................... 5.7

Box 5.0c (New)

Plasma .............................................................................................................................. 5.8

Box 5.2 (New)Information on CH 4 emission factors in laboratory scale .............................................. 5.14

Box 5.3 (New)

Combined system ........................................................................................................... 5.15

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Chapter 5: Incineration and Open Burning of Waste

5 INCINERATION AND OPEN BURNING OF
WASTE
Users are expected to go to Mapping Tables in Annex 1, before reading this chapter. This is required tocorrectly understand both the refinements made and how the elements in this chapter relate to the corresponding
chapter in the 2006 IPCC Guidelines.

5.1

INTRODUCTION

Thermal treatments of waste are classified into incineration, pyrolysis, gasification, plasma, and open burning ofwaste. Pyrolysis, gasification, and plasma are regarded as new technologies for treating solid wastes. In Chapter
5, Volume 5 of the 2006 IPCC Guidelines for National Greenhouse Gas Inventories (2006 IPCC Guidelines),
the new technologies are not included. These new technologies have been applied worldwide and have become
important in some countries. The refinement in this chapter provides CH 4 and N 2 O emission factors ofpyrolysis-melting and gasification-melting plant for treating municipal solid waste (MSW) to be used in theiremission estimates. This chapter updates the oxidation factor for open burning of MSW from experiment data
including uncertainty.
Waste incineration is defined as the combustion of solid and liquid waste in controlled incineration facilities.
Modern refuse combustors have tall stacks and specially designed combustion chambers, which provide highcombustion temperatures, long residence times, and efficient waste agitation while introducing air for more
complete combustion. Types of waste incinerated include MSW, industrial waste, hazardous waste, clinicalwaste and sewage sludge1. The practice of MSW incineration is currently more common in developed countries,
while it is common for both developed and developing countries to incinerate clinical waste.
Pyrolysis is defined as a reduction process that thermochemically converts organic materials into gas and liquid
products mainly containing hydrocarbon components and a solid residue with higher carbon content at elevatedtemperatures in the absence of oxygen (Box 5.0a New).
Gasification is a process that converts organic materials mainly into carbon monoxide, hydrogen, and carbon
dioxide at temperatures above 700℃ with different ratios of gasifying agent such as steam, carbon dioxide,
oxygen, and air. The resulting gas mixture is called as synthesis gas (syngas), mainly used as fuel and/or
chemical feedstock (Box 5.0b New).
Plasma is defined as a partial oxidation process of reacting organic materials in an oxygen starved environment
at high temperature to produce gas and solid products. The highly reactive plasma zone consists largely ofelectrons, ions, and excited molecules along with high energy radiation. In a plasma zone, organic materials arecracked to high portion of gas products such as carbon dioxide, water, carbon monoxide, hydrogen, and lighthydrocarbons along with low quantities of inorganic solid product (slag and metals) (Box 5.0c New).
The new technologies have been mostly applied to produce fuels and chemical feedstocks from waste tires andplastics, and they are also applied to treat MSW to avoid the generations of air pollutants that would arise fromconventional MSW incineration. Although many pyrolysis, gasification, and plasma plants have been applied totreat wastes, many plants have been closed due to some technical problems as well as high cost. Rising
environmental standards and clean energy demands have recently revived the interest in the new technologies
and then new plants are getting installed in developed countries. However, few official data for the emissions ofgreenhouse gases are available for the new technologies. Especially, greenhouse gas emission data from plasma
technology are rarely found.
Since gas products generated from the new technologies are usually collected and used mostly as fuel orchemical feedstock, direct emissions of CH 4 and N 2 O from the new technologies are expected to be quite low
unless gas products containing CH 4 and N 2 O are intentionally vented to the atmosphere. If the gas products
would be combusted to supply energy to inside processes, the emissions of CH 4 and N 2 O are reported under the
Energy Sector. On the other hand, the emissions of CH 4 and N 2 O in gas products are reported under the Waste
Sector provided that the gas products would be released to the atmosphere. If gas, liquid, and solid products
generated from the new technologies would be exported outside for their use or disposal, the emissions of

1 Waste generation, composition and management practices, including waste incineration and open burning, are addressed indetailin Chapter 2 of this volume.

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greenhouse gases are not reported as those from the new technologies themselves, but at the point of their use ordisposal.
BOX 5.0A (NEW)PYROLYSIS

Pyrolysis is a reductive and endothermic reaction to convert carbonaceous substances into lower
molecular weight compounds by applying external energy. The more energy is applied, the smaller
size compounds are produced. CH 4 is one of the smallest compounds generated from pyrolysis
process of carbonaceous substances. Pyrolysis of organic wastes is normally operated attemperature ranges between 300 and 700°C. The pyrolysis process can be shown as below:

Solid wastes or single organic wastes (e.g., plastic and wood) are pre-treated (e.g., drying andpulverizing, etc.) to satisfy technical requirements for the succeeding pyrolysis reaction.
Combustible components of solid wastes are thermally decomposed in pyrolysis reactor to produce
gases and solid residues. The product gas is composed of condensable and non-condensable
fraction which are separated into gas and liquid products, respectively, by a quenching process.
The gas products mainly composed of volatile organic compounds (e.g., CH 4 , C 2 H 6 , etc.), H 2 ,CO, and CO 2 . Liquid products are composed of various aliphatic and aromatic compounds. Solid
products include carbon residues (char) and inorganic components. The solid products may be
combusted in situ for energy recovery within pyrolysis process or transferred outside for energy
and/or chemical feedstock use. The gas products (pyrogases) are combusted in energy supplying
system to provide energy to the pyrolysis reactor or transferred outside for energy or chemical
feedstock use. The external energy-supplying system to the pyrolysis reactor is considered as the
only emission source of greenhouse gases in the pyrolysis plant. The emissions of greenhousegases from the energy-supplying system within the pyrolysis plant are reported under the Energy
Sector. If pyrolysis products would be exported outside for their use or disposal, the emissions ofgreenhouse gases are not reported as those from the pyrolysis plant, but at the point of their use ordisposal.

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BOX 5.0B (NEW)GASIFICATION

Gasification is a conversion process of carbonaceous substances to gas fuel with a high heating
value. Depending upon reaction condition, gasification of solid wastes is accounted for by four
primary reactions: partial oxidation reaction, Boudouard reaction, water gas reaction, andmethanation reaction.
partial oxidation reaction: C + 1⁄2O 2 → COBoudouard reaction: C + CO 2 ↔ 2COwater gas shift reaction: C + H 2 O ↔ CO+ H 2

methanation reaction: 2C + 2H 2 O→ CH 4 + CO 2

The above gasification reactions reveal that the product gas primarily consists of H 2 , CO, and CH 4
and is referred to as synthesis gas (syngas). Solid wastes or single organic wastes (e.g., plastic andwood) are pre-treated (e.g., drying and pulverizing, etc.) to answer technical requirements for thesubsequent gasification reaction. The gasification of combustible components of solid wastes
produces the primary syngas. The gas cleaning system after the gasifier removes acid gases, fineparticulates, heavy metals, and moistures from the primary syngas. The clean syngas may be used
as fuel for generating electrical and thermal energy or steam or exported to other processes forenergy and/or chemical feedstock use. Some portion of clean syngas can be supplied to energy
supplying system within the gasification plant to provide the energy to gasifier. The gasification of
combustible components of solid wastes produces syngas together with liquid and solid products.
Liquid products separated from product gas by a quenching process are known as tars, which aremainly composed of polyaromatic compounds, while the solid products are represented byinorganic components and a little carbon residue.

Since syngas generated from gasification process is used in situ and/or outside for fuel, CH 4
emissions are rarely expected during the gasification process. It is noted that syngas may be vented
directly to atmosphere despite of its rare occurrence. The external energy-supplying system to thegasifier is considered as the only emission source of greenhouse gases in the gasification plant.
The emissions of greenhouse gases from the energy-supplying system within the gasification plant
are reported under the Energy Sector. If gasification products would be exported outside for theiruse or disposal, the emissions of greenhouse gases are not reported as those from the gasification
plant, but at the point of their use or disposal.

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BOX 5.0C (NEW)PLASMA

Plasma technology is regarded as an advanced and pure gasification process. Since plasma
processes are operated at extremely high temperatures in an oxygen deficient condition,
combustible components of solid wastes can be nearly completely converted into syngas. Reaction
residues of plasma process consist of inorganic components including slag and metals. Primarysyngas is produced in plasma rector where one or more plasma arc torches are installed for plasma
generation. The primary syngas is treated by gas cleaning system to produce clean syngas.

Since syngas generated from plasma process may be used in situ as fuel or exported to anotherprocess for energy and/or chemical feedstock use, CH 4 emissions are rarely expected from theplasma process itself. It is noted that syngas may be vented directly to atmosphere despite of its
rare occurrence. The external energy-supplying system to the plasma reactor is considered as the
only emission source of greenhouse gases in the plasma plant. The emissions of greenhouse gases
from the energy recovery system within the plasma plant are reported under the Energy Sector. If
syngas would be exported outside for its use, the emissions of greenhouse gases are not reported as
those from the plasma plant, but at the point of its use.
Emissions of greenhouse gases from thermal treatment of waste include incineration, pyrolysis, gasification,
plasma and open burning without energy recovery are reported in the Waste Sector, while those with energy
recovery are reported in the Energy Sector, both with a distinction between fossil and biogenic carbon dioxide(CO 2 ) emissions. The methodology described in Chapter 5, Volume 5 of the 2006 IPCC Guidelines is applicablein general both to incineration with and without energy recovery. In this refinement, emission factors of CH 4 andN 2 O emissions from new technologies emitted directly to the atmosphere are provided. Co-firing of specificwaste fractions with other fuels is not addressed in this chapter, as co-firing is covered in Volume 2, Energy.
Emissions from agricultural residue burning are considered in the AFOLU Sector, Chapter 5 of Volume 4.
Open burning of waste can be defined as the combustion of unwanted combustible materials such as paper, wood,
plastics, textiles, rubber, waste oils and other debris in nature (open-air) or in open dumps, where smoke andother emissions are released directly into the air without passing through a chimney or stack. Open burning canalso include incineration devices that do not control the combustion air to maintain an adequate temperature anddo not provide sufficient residence time for complete combustion. This waste management practice is used inmany developing countries while in developed countries open burning of waste may either be strictly regulated,or otherwise occur more frequently in rural areas than in urban areas.
Incineration and open burning of waste are sources of greenhouse gas emissions, like other types of combustion.
Relevant gases emitted include CO2, methane (CH4) and nitrous oxide (N2O). Normally, emissions of CO2 fromwaste incineration are more significant than CH4 and N2O emissions.
Consistent with the 1996 Guidelines (IPCC, 1997), only CO2 emissions resulting from oxidation, duringincineration and open burning of carbon in waste of fossil origin (e.g., plastics, certain textiles, rubber, liquidsolvents, and waste oil) are considered net emissions and should be included in the national CO2 emissions
estimate. The CO2 emissions from combustion of biomass materials (e.g., paper, food, and wood waste)contained in the waste are biogenic emissions and should not be included in national total emission estimates.
However, if incineration of waste is used for energy purposes, both fossil and biogenic CO2 emissions should be
estimated. Only fossil CO2 should be included in national emissions under Energy Sector while biogenic CO2
should be reported as an information item also in the Energy Sector. Moreover, if combustion, or any otherfactor, is causing long term decline in the total carbon embodied in living biomass (e.g., forests), this net releaseof carbon should be evident in the calculation of CO2 emissions described in the Agriculture, Forestry and Other
Land Use (AFOLU) Volume of the 2006 Guidelines.

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Chapter 5: Incineration and Open Burning of Waste

Guidance on methodological choices for estimating and reporting CO 2 , CH4 and N2O emissions fromincineration and open burning reported in Chapter 5, Volume 5 of the 2006 IPCC Guidelines are valid toestimate CH 4 and N 2 O from new technologies. This refinement provides guidance on choice of CH 4 and N 2 O
emission factors for pyrolysis and gasification for specific type of plant.
Traditional air pollutants from combustion - non-methane volatile organic compounds (NMVOCs), carbon
monoxide (CO), nitrogen oxides (NOx), sulphur oxides (SOx) - are covered by existing emission inventory
systems. Therefore, the IPCC does not provide new methodologies for these gases here, but recommends thatnational experts or inventory compilers use existing published methods under international agreements. Some
key examples of the current literature providing methods include EMEP/CORINAIR Guidebook (EMEP 2004),
US EPA's Compilation of Air Pollutant Emissions Factors, AP-42, Fifth Edition (US EPA, 1995), EPA Emission
Inventory Improvement Program Technical Report Series, Vol. III Chapter 16: Open Burning (US EPA, 2001).
The estimation of indirect N2O emissions, resulting from the conversion of nitrogen deposition to soils due toNOx emissions from waste incineration and open burning, is addressed in Section 5.4.3 of this chapter. Generalbackground and information on the reporting of the indirect N2O emissions is given in Chapter 7, Precursors andIndirect Emissions, of Volume 1, General Guidance and Reporting.

5.2

METHODOLOGICAL ISSUES

The choice of method will depend on national circumstances, including whether incineration and open burningof waste are key categories in the country, and to what extent country- and plant-specific information is available
or can be gathered.
For waste incineration, the most accurate emission estimates can be developed by determining the emissions on aplant-by-plant basis and/or differentiated for each waste category (e.g., MSW, sewage sludge, industrial waste,
and other waste including clinical waste and hazardous waste). The methods for estimating CO2, CH4 and N2Oemissions from incineration and open burning of waste vary because of the different factors that influenceemission levels. Estimation of the amount of fossil carbon in the waste burned is the most important factor
determining the CO2 emissions. The non-CO2 emissions are more dependent on the technology and conditions
during the incineration process.
Intentional burning of waste on solid waste disposal sites is sometimes used as a management practice in somecountries. Emissions from this practice and those from unintentional fires (accidental fires on solid waste
disposal sites) should be estimated and reported according to the methodology and guidance provided for open
burning of waste.
The general approach to calculate greenhouse gas emissions from incineration and open burning of waste is toobtain the amount of dry weight of waste incinerated or open-burned (preferably differentiated by waste type)
and to investigate the related greenhouse gas emission factors (preferably from country-specific information on
the carbon content and the fossil carbon fraction). For CO2 emissions from incineration and open burning ofwaste, the basic approach is given here as an example of a consecutive approach:•

Identify types of wastes incinerated/open-burned: MSW, sewage sludge, industrial solid waste, and otherwastes (especially hazardous waste and clinical waste) incinerated/open-burned.

•

Compile data on the amount of waste incinerated/open-burned including documentation on methods usedand data sources (e.g., waste statistics, surveys, expert judgement): Regional default data are also provided
in Table 2.1 (Updated) in Chapter 2, Waste Generation, Composition and Management Data, and countryspecific data for a limited number of countries in Annex 2A.1 (Updated) of this Volume. The default data
should be used only when country-specific data are not available. For open burning, the amount of waste
can be estimated based on demographic data. This is addressed in Section 5.3.2.

•

Use default values provided on dry matter content, total carbon content, fossil carbon fraction and oxidation
factor (see Section 5.4.1.3) for different types of wastes: For MSW, preferably identify the waste
composition and calculate the respective dry matter content, total carbon content, and fossil carbon fraction
using default data provided for each MSW component (plastic, paper, etc) in Section 2.3, Waste
composition, of this Volume.

•

Calculate the CO2 emissions from incineration and open burning of solid wastes.

•

Provide data in the worksheets given in Annex 1 of this Volume 5 of the 2006 IPCC Guidelines.

For other waste types and other greenhouse gases, the approach usually does not differentiate as much as for the
MSW in terms of waste composition. Detailed guidance on the choice of method, activity data and emission

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factors for all major types of waste to estimate the emissions from relevant waste incineration and burning
practices is outlined in the following sections.
Methodology from the 2006 IPCC Guidelines can be used to estimate emission from gasification, pyrolysis andplasma. Emission factors of CH 4 and N 2 O from pyrolysis and gasification are provided in new Tables 5.3A and
5.4A.

5.2.1

Choice of method for estimating CO2 emissions

No refinement.

5.2.1.1

T IER 1

No refinement.

5.2.1.2

T IER 2

No refinement.

5.2.1.3

T IER 3

No refinement.

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5.2.1.4

CO 2 EMISSIONS FROM INCINERATION OF FOSSIL LIQUID
WASTE

No refinement.

5.2.2

Choice of method for estimating CH 4 emissions

No refinement.

5.2.2.1

T IER 1

No refinement .

5.2.2.2

T IER 2

No refinement.

5.2.2.3

T IER 3

No refinement.

5.2.3

Choice of method for estimating N 2 O emissions

No refinement.

5.2.3.1

T IER 1

No refinement.

5.2.3.2

T IER 2

No refinement.

5.2.3.3

T IER 3

No refinement.

5.3

CHOICE OF ACTIVITY DATA

No refinement.

5.3.1

Amount of waste incinerated

No refinement.

5.3.2

Amount of waste open-burned

No refinement.

5.3.3

Dry matter content

No refinement.

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5.4

CHOICE OF EMISSION FACTORSEmission factors in the context of incineration and open burning of waste relate the amount of greenhouse gas
emitted to the weight of waste incinerated or open-burned. In the case of CO2, this applies data on the fractionsof carbon and fossil carbon in the waste. For CH4 and N2O, this primarily depends on the treatment practice andthe combustion technology. For the estimation of CO2, CH4 and N2O emissions from incineration and open
burning of waste, guidance on choice of the emission factors is outlined in the following sections.

5.4.1

CO 2 emission factors

It is generally more practical to estimate CO2 emissions from incineration and open burning of waste using
calculations based on the carbon content in the waste, instead of measuring the CO2 concentration.
Default values for parameters related to emission factors are shown in Table 5.2 (Updated). Each of these factors
is discussed in detail in the sections below 2.
TABLE 5.2 (UPDATED)DEFAULT DATA FOR CO 2 EMISSION FACTORS FOR INCINERATION AND OPEN BURNING OF WASTEManagement
practice

Parameters

MSW

Industrial
Waste (%)

Clinical
Waste (%)

SewageFossil liquid
Sludge (%) waste (%)
Note 4Note 5

Dry matter content in % of
wet weightsee Note 1

NA

NA

NA

NA

Total carbon content in % of
dry weightsee Note 1

50

60

30

80

Fossil carbon fraction in %of total carbon content

see Note 2

90

40

0

100

incineration

100

100

100

100

100

Open- burning(see Note 3,6)

71

NO

NO

NO

NO

Oxidation factor in % ofcarbon input

NA: Not Available, NO: Not Occurring
Note 1: Use default data from Table 2.4 in Section 2.3 Waste composition and equation 5.8 (for dry matter), Equation 5.9 (for carbon
content) and Equation 5.10 (for fossil carbon fraction).
Note 2: Default data by industry type is given in Table 2.5 in Section 2.3 Waste composition. For estimation of emissions, use equations
mentioned in Note 1.
Note 3: A default value of 71 percent is provided from the experimental study in Japan. Its uncertainty is +/-8 percent. Reference:
Yamada et al. (2010)
Note 4: See Section 2.3.2 Sludge in Chapter 2.
Note 5: The total carbon content of fossil liquid waste is provided in percent of wet weight and not in percent of dry weight (GIO, 2005).
References: GPG2000 (IPCC, 2000), Lead Authors of the 2006 IPCC Guidelines, Expert judgement.
Note 6: The residue after open-burning contains unburned carbon in the form of ash or other solid residue. The fate of the unburned
carbon is to be tracked and the emissions from the disposition of the unburned carbon is to be accounted for in the appropriate
category. When open-burning takes place in SWDS, burned fraction of DOC is subtracted from the DOC in SWDS (See Section
3.2.1 of Chapter 3, Volume 5 of the 2006 IPCC Guidelines). If unburned carbon is placed at the surface of SWDS with aerobic
condition, emission is not taken into account. When the condition is regarded as anaerobic by further piling of waste, this fraction
is categorised in slowly degrading waste.

5.4.1.1

T OTAL CARBON CONTENT

No refinement.

5.4.1.2

F OSSIL CARBON FRACTION

No refinement.

2 The parameters total carbon content in percent of dry weight and fossil carbon fraction in percent of total carbon content

could be combined to the parameter: fossil carbon content in percent of dry weight.

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5.4.1.3

O XIDATION F ACTOR

When waste streams are incinerated or open-burned most of the carbon in the combustion product oxidises toCO2. A minor fraction may oxidise incompletely due to inefficiencies in the combustion process, which leavesome of the carbon unburned or partly oxidised as soot or ash. For waste incinerators it is assumed that the
combustion efficiencies are close to 100 percent, while the combustion efficiency of open burning issubstantially lower. If oxidation factors of waste incineration below 100 percent are applied, these need to be
documented in detail with the data source provided. Table 5.2 (Updated) presents updated default oxidation
factor for open burning of MSW and total carbon content in percent of dry weight of sewage sludge.
If the CO2 emissions are determined on a technology- or plant-specific basis in the country, it is good practice to
use the amount of ash (both bottom ash and fly ash) as well as the carbon content in the ash as a basis fordetermining the oxidation factor.
The 2006 IPCC Guidelines provide default oxidation factors for open burning of MSW. This refinement updates
the default parameter of oxidation factor from experiment from Japan. The condition of combustion issmouldering with 35 percent of the moisture content. In updated Table 5.2, except the default values of oxidation
factor of MSW and total C content in sewage sludge, all values are retrieved from the 2006 IPCC Guidelines.

5.4.2

CH 4 emission factors

CH4 emissions from waste incineration are much dependent on the continuity of the incineration process, theincineration technology, and management practices. The most detailed observations have been made in Japan(GIO, 2004), where the following CH4 emission factors based on technology and operation mode are obtained.
Continuous incineration includes incinerators without daily start-up and shutdown. Batch type and semicontinuous incineration mean that the incinerator is usually started-up and shutdown at least once a day. These
differences in operation are at the origin of difference in emission factors. It is sometimes observed that theconcentrations of CH4 in the exhaust gas of the furnace are below the CH4 concentrations in intake gas of theincinerator (GIO, 2005). Because of the low concentrations and high uncertainties, it is here good practice toapply an emission factor of zero (see Section 5.2.2.3).
For continuous incineration of MSW and industrial waste, it is good practice to apply the CH4 emission factors
provided in Volume 2, Chapter 2, Stationary Combustion. For other MSW incinerators (semi-continuous andbatch type), Table 5.3 shows CH4 emission factors reported by Greenhouse Gas Inventory Office of Japan (GIO,
Japan). The CH4 emission factors of other industrial waste incinerators are differentiated by waste type, rather
than technology (GIO, 2005). In Japan, the CH4 emission factors of waste oil and of sludge are 0.56 g CH4/t wet
weight and 9.7 g CH4/t wet weight, respectively.
For open burning of waste, a CH4 emission factor of 6500 g / t MSW wet weight has been reported (EIIP, 2001).
This factor should be applied as a default, unless another CH4 emission factor seems more appropriate.
If country-specific data are available, these should be applied instead and the method used to derive them as wellas the data sources need to be documented in detail.
TABLE 5.3
CH 4 EMISSION FACTORS FOR INCINERATION OF MSW
Type of incineration/technology

CH4 Emission Factors(kg/Gg waste incinerated on a wet weight basis)stoker0.2

fluidised bed Note1~0stoker6

fluidised bed

188

stoker60

fluidised bed

237

Continuous incineration

Semi-continuous incineration

Batch type incineration
Note 1: In the study cited for this emission factor, the measured CH4 concentration in the exhaust air was lower than the concentration inambient air.
Source: Greenhouse Gas Inventory Office of Japan, GIO 2004.

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This refinement presents the emission factors of CH 4 for new technologies of pyrolysis and gasification.
Although a plenty of information on CH 4 emissions from the pyrolysis and gasification of solid wastes areavailable from scientific research literatures (Box 5.2 (New)), very few data are obtainable for commercial plantsof new technologies. Table 5.3a (New) shows the CH 4 emission factors of MSW from a combined system ofpyrolysis-melting and gasification-melting processes on a commercial scale (Box 5.3 (New)). In commerciallyoperated pyrolysis-melting and gasification-melting plants, condensable and non-condensable gases including
CH 4 generated from the pyrolysis and gasification reactor are mostly oxidized at the subsequent melting furnace,leading to the low CH 4 emissions from the stack. If country-specific data are unavailable for pyrolysis-melting
and gasification-melting plants, it is good practice to apply the default CH 4 emission factor corresponding toreactor type for both pyrolysis-melting and gasification-melting plants. The emissions of greenhouse gases fromthe combined system with energy recovery system are reported under the Energy Sector.

TABLE 5.3A (NEW)
CH 4 EMISSION FACTORS FOR PYROLYSIS-MELTING AND GASIFICATION-MELTING PLANT OF MSW
Process

Pyrolysis-melting andgasification-melting

Operating temperature (°C)
Pyrolysis: 300 ~ 600°C
Gasification: 700~900°C
Melting: 1300~1700°C

1

Ministry of the Environment, Japan (2010)2

Lee et al. (2015)

CH 4 Emission Factors(g/t waste on a wet basis)

Reactor Type5.811,2 (n=11)

Shaft type9.701 (n=10)

Fluidized bed type5.401 (n=5)

Rotary kiln type

BOX 5.2 (NEW)INFORMATION ON CH4 EMISSION FACTORS IN LABORATORY SCALE

A plenty of information on CH 4 emission from pyrolysis and gasification process in laboratory
scale are available for various waste types and reaction conditions. According to the scientificresearch literatures (Rahman et al. 2001, He et al. 2010, and Wu et al. 2016), CH 4 emission fromthe pyrolysis and gasification process of solid wastes are dependent on the types of waste andtechnology as well as the operating conditions. CH 4 emissions from the pyrolysis and gasification
process of solid wastes increase with increasing operating temperature. The higher pyrolysis
temperature can supply more energy to break down the high-molecular-weight components ofsolid organic wastes into low-molecular-weight compounds such as CH 4 .

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Chapter 5: Incineration and Open Burning of Waste

BOX 5.3 (NEW)COMBINED SYSTEMFor MSW treatment, a combined system of two processes was mostly introduced. The first processof the combined system is either pyrolysis or gasification, whereas the second one is represented
by melting process.

In the first reactor where pyrolysis or gasification occurs, MSW are thermally decomposed to yield
the primary gas with high heating values and carbon residues (char) in the absence of oxygen or
oxygen starved environment. The primary gas and char are transported to the melting furnace
operating at high temperatures (>1000°C) under oxidation conditions. Primary gas and char are
oxidized to produce the secondary gas at the melting furnace. After removing the air pollutantsfrom the secondary gas, the flue gas mainly composed of CO 2 and H 2 O is emitted to the air
through the stack. Since pyrogas and syngas generated from pyrolysis and gasification,
respectively, are mostly oxidized at the melting furnace, the emissions of greenhouse gases fromthe stack is expected to be negligibly low.

5.4.3

N 2 O emission factors

Nitrous oxide emissions from waste incineration are determined by a function of the type of technology andcombustion conditions, the technology applied for NOx reduction as well as the contents of the waste stream. As
a result, emission factors can vary from site to site.
Several countries have reported N 2 O emissions from waste incineration in their national inventory reports. Table
5.4 shows examples of emission factors that have been used for incineration of MSW.
The differences in the emission factors are mainly caused by varying technologies in the context of NO x removal.

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Volume 5: Waste

TABLE 5.4
N2O EMISSION FACTORS FOR INCINERATION OF MSWCountryType of Incineration / Technology

Japan1

Continuous incineration

Emission factor for MSW(g N2O/t MSW incinerated)

Weight basis

Stocker47

wet weight

Fluidised bed

67

wet weight

Stocker

41

wet weight

Fluidised bed

68

wet weight

Stocker56

wet weight

Fluidised bed

221

wet weight

Germany2

8

wet weight

Netherlands3

20

wet weight

Austria4

12

wet weight

Semi-continuous incineration

Batch type incineration

1

GIO, 2005.

2

Johnke 2003.

3

Spakman 2003.

4

Anderl et al. 2004.

The emission factors of N 2 O for pyrolysis, gasification, and plasma technology of waste vary with types ofwaste, reactor type, and operating conditions. In this refinement, updated N 2 O emissions from pyrolysis-melting
and gasification-melting plants for treating MSW are provided.
Since most national regulations for air pollutants rarely require monitoring N 2 O emissions from thermal
treatment plants of solid wastes, a few official data are available for N 2 O emission from pyrolysis, gasification,and plasma plants. Especially, N 2 O emission data are unavailable for plasma technology. Table 5.4a (New)indicates the N 2 O emissions from pyrolysis-melting and gasification-melting plants of MSW on a commercialscale basis. The emission factor of N 2 O from pyrolysis-melting plant is much lower than that from shaft furnace
reactor, indicating that the reactor type plays an important role in N 2 O generation. It is also expected that thewaste type and operating conditions influence the generation patterns of N 2 O. If country-specific data areunavailable for pyrolysis-melting and gasification-melting plants, it is good practice to apply the default N 2 O
emission factor corresponding to reactor type for both pyrolysis-melting and gasification-melting plants.
TABLE 5.4A(NEW)N 2 O EMISSION FACTORS FOR PYROLYSIS-MELTING AND GASIFICATION-MELTING PLANT OF MSW
Process

Pyrolysis-melting andgasification-melting

Operating temperature (°C)
Pyrolysis: 300 ~ 600°C
Gasification: 700~900°C
Melting: 1300~1700°C

1

Ministry of the Environment, Japan (2010)2

Lee et al. (2015)

3

Yoon (2017)

5.5

N 2 O Emission Factors,(g/t waste on a wet basis)

Reactor Type17.41,2 (n=11)

Shaft type5.801 (n=10)

Fluidized bed type8.381,3 (n=6)

Rotary kiln type

COMPLETENESS

No refinement.

5.6

DEVELOPING A CONSISTENT TIME SERIESNo refinement.

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Chapter 5: Incineration and Open Burning of Waste

5.7

UNCERTAINTY ASSESSMENT

No refinement.

5.7.1

Emission factor uncertainties

No refinement.

5.7.2

Activity data uncertainties

No refinement.

5.8

QA/QC, REPORTING AND DOCUMENTATION

5.8.1

Inventory Quality Assurance/Quality Control(QA/QC)No refinement.

5.8.2

Reporting and Documentation

No refinement.

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Volume 5: Waste

References
References newly cited in the 2019 Refinement
He, M., B. Xiao, Liu, S., Hu, Z., Guo, X., Luo, S. & Yang, F. (2010) Syngas production of pyrolysis ofmunicipal solid waste (MSW) with dolomite as downstream catalysts, J. Anal. Appl. Pyrolysis 87: 181-187.
Lee, J., Kang, S., Kim, S., Kang, S., Lee, S. & Jeon, E. (2015) Development of non-CO 2 emission factors from MSW
pyrolysis melting treatment in Korea, Environmental Earth Sciences 74: 4157-4162.
Ministry of the environment, Japan (2010) Survey study on improving the accuracy of emission factors forgreenhouse gas emissions from the waste sector (In Japanese).
Rahman, A.N.E., Khaleel Akmal, M.A. & Prasa, K.B.S. (2001) Pyrolysis of solid waste, J. of Scientific & Industrial
Research 60: 52-59.
Wu, W., Zhou, X., Zhang, P., Liu, W.L., Danzeng, D., Wang, S. & Wang, Y. (2016) Study on characteristics ofsynthesis gas generation during catalytic gasification of municipal solid waste, Procedia Environmental Sciences
31: 505-513.
Yamada M (2010). Report of Research on improvement of greenhouse gas inventory in waste field and evaluation of
reduction measures, National Institute for Environmental Studies (NIES), Japan.
Yoon, H.K, Lee, D.K., Cho, C.S., Kang, S.M., Yoon, Y. J., Jeon, Y.J. & Jeon, E.C. (2017) The Development of
N 2 O Emission Factor at Killn Type Pyrolysis Melting Facility, Journal of Climate Change Research, 8(3):231-237.

References copied from the 2006 IPCC Guidelines
Anderl, M., Halper, D., Kurzweil, A., Poupa S., Wappel, D., Weiss, P. and Wieser M. (2004). Austria’s National
Inventory Report 2004: Submission under the United Nations Framework Convention on Climate Change.EMEP.
(2004). EMEP/CORINAIR Guidebook, Update September 2004.
http://reports.eea.eu.int/EMEPCORINAIR4/en/group_09.pdf
GIO (2004). National Greenhouse Gas Inventory Report of JAPAN. Ministry of the Environment/ Japan
Greenhouse Gas Inventory Office of Japan (GIO) / Center for Global Environmental Research (CGER) /National Institute for Environmental Studies (NIES). October 2004.
GIO (2005). National Greenhouse Gas Inventory Report of JAPAN. Ministry of the Environment/ Japan
Greenhouse Gas Inventory Office of Japan (GIO) / Center for Global Environmental Research (CGER) /National Institute for Environmental Studies (NIES).
IPCC (1997a). Revised 1996 IPCC Guidelines for National Greenhouse Inventories, Volume 3 Reference
Manual. Houghton, J.T., Meira Filho, L.G., Lim, B., Tréanton, K., Mamaty, I., Bonduki, Y., Griggs, D.J. andCallander, B.A. (Eds). Intergovernmental Panel on Climate Change (IPCC), IPCC/OECD/IEA, Paris, France.
IPCC (1997b). Revised 1996 IPCC Guidelines for National Greenhouse Inventories, Volume 2 Workbook.
Houghton, J.T., Meira Filho, L.G., Lim, B., Tréanton, K., Mamaty, I., Bonduki, Y., Griggs, D.J. andCallander, B.A. (Eds). Intergovernmental Panel on Climate Change (IPCC), IPCC/OECD/IEA, Paris, France.
IPCC (2000). Good Practice Guidance and Uncertainty Management in National Greenhouse Gas Inventories,
Penman, J., Kruger, D., Galbally, I., Hiraishi, T., Nyenzi, B., Emmanuel, S., Buendia, L., Hoppaus,
R.,Martinsen, T., Meijer, J., Miwa, K. and Tanabe, K. (Eds). Intergovernmental Panel on Climate Change(IPCC), IPCC/OECD/IEA/IGES, Hayama, Japan.
Johnke, B. (2003). Emissionsberichterstattung / Inventarerstellung für das Jahr 2002 [Emission reporting /preparation of the inventory for the year 2002]. Umweltbundesamt, Berlin 2003 [In German].
Spakman, J., van Loon, M.M.J., van der Auweraert, R.J.K., Gielen, D.J., Olivier, J.G.J. and Zonneveld, E.A.
(2004). Method for calculating greenhouse gas emissions. Emission Registration Series/Environmental
Monitor No.37b, MinVROM. The Hague 2003.
US EPA (1995). US EPA's Compilation of Air Pollutant Emissions Factors, AP-42, Edition 5, United States
Environmental Protection Agency (US EPA). http://www.epa.gov/ttn/chief/ap42/
US EPA (1997). Control Technology Center. Evaluation of Emissions from the Open Burning of Household
Waste in Barrels. Volume1. Technical Report. United States Environmental Protection Agency (US EPA).

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Chapter 5: Incineration and Open Burning of Waste

US EPA (2001). US EPA Emission Inventory Improvement Program. Volume III Chapter 16 Open Burning.
UnitedStatesEnvironmental
Protection
Agency(US
EPA).
http://www.epa.gov/ttn/chief/eiip/techreport/volume03/iii16_apr2001.pdf

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