33

Assessment of greenhouse gas

emissions in the production

and use of fuel ethanol in Brazil

Government of the State of São Paulo

Geraldo Alckmin – Governor

Secretariat of the Environment

José Goldemberg – Secretary

Isaias de Carvalho Macedo – Núcleo Interdisciplinar de Planejamento

Energético da Universidade Estadual de Campinas – NIPE/UNICAMP

Manoel Regis Lima Verde Leal – Centro de Tecnologia

Copersucar (CTC/Copersucar), Piracicaba

João Eduardo Azevedo Ramos da Silva – Centro de Tecnologia

Copersucar (CTC/Copersucar), Piracicaba

March 2004
5

cv Metric horsepower (1cv = 0,7355 kW)

GJ Gigajoule

ha Hectare

h Hour

kcal Kilocalorie

kg Kilogram

kWh Kilowatt hour

l Liter

MJ Megajoule

Pol Polarization (sucrose content)

t Metric ton

TC Metric ton of cane

TCH Metric ton of cane per hour

Chemical compounds

CH4 Methane

CO Carbon monoxide

CO2 Carbon dioxide

H2SO4 Sulfuric acid

K2O Potassium fertilizers

N Nitrogen

NH4 Ammonium radical

N2O Nitrous oxide

NOx Nitrogen oxides

P2O5 Phosphate fertilizers

BEN Balanço Energético Nacional

(National Energy Balance)

CMA Controle Mútuo Agrícola

(Agricultural Benchmark Program)

CMI Controle Mútuo Industrial

(Industrial Benchmark Program)

CTC Centro de Tecnologia Copersucar

(Copersucar Technology Center)

C-S Center-South region (Brazil)

IPCC Intergovernmental Panel on

Climate Change

NIPE Núcleo Interdisciplinar de

Planejamento Energético – UNICAMP

(Interdisciplinary Nucleus of Energy

Planning – UNICAMP)

PAMPA Programa de Acompanhamento Mensal

de Performance Agrícola (Agricultural

Monthly Performance Follow up Program)

SP São Paulo State

UNICAMP Universidade de Campinas

(University of Campinas)

GHG Greenhouse gases

GWP Global warming potential

HHV Higher heating value

LHV Lower heating value

RS Reducing sugars

Tables and figures

Figure 1 – Energy balance – Scenario 1 17

Figure 2 – GHG (*) Emissions – Scenario 1 19

Table 1 – Energy consumption in sugar cane production 15

Table 2 – Energy consumption in the production of ethanol 16

Table 3 – Energy generation and consumption in the production of sugar cane and ethanol 16

Table 4 – Ethanol life cycle emissions 19

Table 5 – Sugar cane yield (averages for harvest seasons 1998/99 to 2002/03) 20

Table 6 – Agricultural operations: equipment 21

Table 7 – Consumption of diesel oil in agricultural operations 22

Table 8 – Harvest equipment 22

Table 9 – Fertilizer application 25

Table 10 – Rate of fertilizer application 25

Table 11 – Energy in fertilizers 26

Table 12 – Use of agricultural equipment 27

Table 13 – Energy for the production and maintenance of equipment 27

Table 14 – Energy cost of equipment 27

Table 15 – Surplus bagasse energy 29

Table 16 – Energy in the chemicals and lubricants used in the industrial sector 30

Table 17 – Energy in the buildings and working areas 30

Table 18 – Energy in equipment fabrication 30

Table 19 – Energy use related to equipment and buildings in the industrial area 31

Table 20 – Energy cost for different equipment and materials 31

Table 21 – Fossil fuel emissions 32

Table 22 – Methane emissions from cane field burning 34

Abbreviations Units
7

Contents

Preface 9

Executive summary 10

Introduction 11

Objective 11

Methodology 11

Database 12

Systems and emission flows definition 13

Emissions

Use of fossil fuel in sugar cane production 15

Use of fossil fuel in the industrial production of ethanol 15

GHG emissions due to the use of fossil fuels 17

Other GHG emissions in the production and use of ethanol 17

Avoided emissions 18

Balance of emissions and conclusion 18

Annexes

Annex 1: Sugar cane production 20

Annex 2: Use of energy in the industrial processing of cane to ethanol 28

Annex 3: Notes and supplementary data 32

References 37
9

Preface

One of the main tasks of the Secretariat of the Environment of the

 State of São Paulo is the improvement of air quality in the State’s

 urban areas. The addition to gasoline of 20-25% of ethanol is an

important contribution to this end.

The substitution of gasoline by alcohol has another important

consequence: the reduction of greenhouse gas emission (principally CO2

)

provided that in the production of the ethanol, the fossil fuel contribution is

minimized. This contribution stems from the energy needed to produce

the raw materials used in farming and in the industrial process (fertilizers,

lime, sulfuric acid, lubricants etc.) as well as electricity and fuels acquired

by the producer (direct energy consumptions).

To consider ethanol as a renewable (or an “almost renewable”)

fuel, it is essential that the production fossil fuels’ contribution is small, just

as with the emission of greenhouse gases not directly associated with the

use of fossil fuels in the entire cycle of production and usage.

Along the years evaluations of this contribution have been made

by various groups of specialists, with highly encouraging results.

With the increase in the numbers of ethanol production units and

with the advances of technology, the Secretariat of the Environment felt it

to be necessary to seek from University of Campinas (UNICAMP) an

updating of these evaluations. This update was carried out with data

obtained also from the Copersucar Technology Center (CTC/Copersucar).

This report is the result of this work.

Prof. José Goldemberg

Secretary of the Environment
1010

S

10

Executive summary

ugar cane energy products, ethanol and

bagasse, have made a significant contribution

to the reduction of greenhouse gas (GHG)

emissions in Brazil, substituting fossil fuels,

gasoline and fuel oil, respectively.

However, fossil fuels are used in the

operations of planting, harvesting, transportation

and processing of the sugar cane, resulting in

GHG emissions. Energy and GHG balances

are required to evaluate the net effects during

the complete well-to-wheel cycle of ethanol,

i.e. ethanol production from sugar cane and its

use as fuel in the transport sector. To facilitate

the comparison with other studies, the GHG

data are presented as CO2 equivalent

emissions (CO2

eq.).

In the energy balance three levels of

energy flows are considered, making it easier

to compare with other energy balances.

Level 1 – Only the direct consumption of

external fuels and electricity (direct energy

inputs) is considered.

Level 2 – This is the additional energy

required for the production of chemicals and

materials used in the agricultural and

industrial processes (fertilizers, lime, seeds,

herbicides, sulfuric acid, lubricants, etc.).

Level 3 – This is the additional energy

necessary for the manufacture, construction

and maintenance of equipment and buildings.

Due to the diversity of the database

for the technical parameters related to the

sugar cane and ethanol production in Brazil,

a limited but reliable database was prepared

using the information available at Copersucar.

This database has the advantage of traceability

and consistent references.

Two cases have been considered in the

evaluation of energy flows: Scenario 1 based on the

average values of energy and material consumption

and Scenario 2 based on the best values being

practiced in the sugar cane sector (minimum

consumption with the use of the best technology in

use in the sector). In both Scenarios the balance is

referred to one metric ton of cane (TC).

Under these conditions, the results obtained

for energy consumption were: 48,208 kcal/TC and

45,861 kcal/TC in the agricultural sector for

Scenarios 1 and 2, respectively, and 11,800 kcal/

TC and 9,510 kcal/TC in the industrial sector for

Scenarios 1 and 2, respectively. The total energy

consumptions for Scenario 1, 60,008 kcal/TC, and

Scenario 2, 55,371 kcal/TC, compare very favorably

with the total energy production (ethanol and surplus

bagasse) of 499,400 kcal/TC and 565,700 kcal/TC,

for Scenarios 1 and 2, respectively. The ratios of

output energy (renewable) to input energy (fossil)

are 8.3 and 10.2, for Scenarios 1 and 2, respectively.

In the GHG balance the emissions have

been divided into two groups: emissions derived

from the use of non renewable energy (diesel and

fuel oil) and emissions from other sources (cane trash

burning, fertilizer decomposition).

For the first group the calculated values were

19.2 kg CO2eq./TC and 17.7 kg CO2eq./TC for

Scenarios 1 and 2, respectively, while the values

determined for the second group were 12.2 kg

CO2eq./TC for both Scenarios.

The emissions avoided due to the substitution

of ethanol for gasoline and surplus bagasse for fuel

oil, deducting the above values, gives a net result

of 2.6 and 2.7 t CO2

eq./m3 anhydrous ethanol and

1.7 and 1.9 t CO2eq./m3

 of hydrous ethanol, for

Scenarios 1 and 2, respectively.
11

T

Introduction

he Brazilian sugar cane agribusiness is an

economic activity responsible for 2.2% of

GDP, generating an income of over US$ 8

billion and creating approximately one

million direct jobs: more than 400,000 in the

State of São Paulo alone – the country’s

largest producer State – as well as fostering

the economic development of a large

number of municipalities and contributing to

the employment of a large number of

workers in the rural areas.

The activity has a positive environmental differential that is the efficient

production of fuel grade ethanol from sugar

cane. The extensive use of fuel ethanol in

Brazil, whether as a 25% blend with gasoline

(gasohol), or used as a neat fuel in vehicles

equipped with dedicated alcohol engines or

used in the newly produced flex fuel

vehicles, which can operate on neat

ethanol, gasohol or any intermediate blend,

places Brazil as a leader in carbon emission

reduction and Greenhouse Effect mitigation.

The production of ethanol in the 2003/

2004 crop season will reach the significant

volume of 14.4 billion liters and the CenterSouth region, which includes São Paulo State,

will respond for 89.6% of the total.

In addition to the production of

ethanol, the industrial processing of sugar

cane generates bagasse, another valuable

product. This residue also adds to the

industry’s positive environmental differential

because it has been widely used to replace

fossil fuels in the production of industrial heat

and electricity in the sugar mills and

distilleries thereby boosting the abatement

potential of greenhouse gases emission.

The present work is a contribution to

a better understanding of the renewable

energy value and energy efficiency of this

important industrial sector.

Objective

This work presents the life cycle

analysis of the GHG emissions in the

production and use of ethanol, under the

typical conditions found in Brazilian sugar

and ethanol mills. It also presents the emissions

derived from fossil fuel consumption and those not

related to the use of energy.

Data collected in 2002 have been used for

the latest update of the analysis of energy consumption

in the sugar cane ethanol production at Copersucar

mills undertaken in 19851, then updated in 19982.

The observations made in the first report,

especially those concerning the correct definition

of the boundaries of the process analysed, remain

valid. Some of the parameters defined at that time

have been maintained in this report, due to the

difficulties found in their updating. However this fact

can be considered of little importance since it would

have only a very small impact on the energy

consumption figures.

The evaluation of the GHG emissions in the

production and use of ethanol is also an update and

a revision of previous work performed at the

Copersucar Technology Center (CTC), whose studies

were published in 19923

 and revised in 1998, with

1996 data4

.

Methodology

The energy flows have been considered in

two situations: one (Scenario 1), based on the average

values of energy and chemicals’ utilizations, and the

other (Scenario 2), based on the best existing values

(minimum consumption values resulting from the

application of the best technology in use by the

sector). The use of these scenarios allows not only

the characterization of the present situation (Scenario

1) but also the estimation of a situation that may

become reality in the medium term (Scenario 2) by

the widespread use of good practices already being

used in some mills. Technologies that are already

developed, or in the process of being developed, but

are not used in a significant degree today, have not

been considered in this work.

Technologies in the process of gradual

introduction, that may have significant impact on

the GHG emissions, have been considered at the

present degree of utilization. This is the case of

mechanically harvested unburned cane, without

trash recovery for power generation.

The energy flows have been considered

in three levels, to facilitate the comparison with

other studies:
12

Level 1 – Only the direct consumptions of external fuels

and electricity (direct energy inputs) are considered.

Level 2 – The energy required for the production of

chemicals and materials used in the agricultural and

industrial processes (fertilizers, lime, seeds,

herbicides, sulfuric acid, lubricants etc.) is added.

Level 3 – The energy necessary for the fabrication,

construction and maintenance of equipment and

buildings is added.

The parameter values recommended by the

Intergovernmental Panel on Climate Change (IPCC)7

have been used in the GHG emission calculations

whenever available.

Database

A complete countrywide database for the

sugar cane sector has not yet been fully established,

thus the use of a database covering part of the sector

but based on reliable and traceable information has

been preferred. It is important to point out that this

database is representative of the agricultural and

industrial practices, especially of the Center-South

region, accounting for approximately 85% of the

sugar cane production in Brazil.

Under these considerations the following

documents have been selected as references for the

energy balance of ethanol production in Brazil.

– Copersucar: Agricultural Benchmark Program (26

to 31 mills in the State of São Paulo) – These reports

present dozens of performance parameters in the

agricultural sector of a group of Copersucar

associated mills. They have been prepared for many

years, bring monthly and annual averages, and have

been fully discussed among the participating mills.

– Copersucar: Industrial Benchmark Program (17 to

22 mills in the State of São Paulo) – These reports

present the industrial sector performance parameters

(efficiencies, consumption of chemicals etc.) of a

selected part of Copersucar member mills. They have

been also extensively discussed among the participants,

and show the monthly and annual averages.

– Copersucar: Agricultural Monthly Performance

Follow up Program (98 mills in the Center-South

region) – These reports present the agricultural

sector parameters for a larger number of

participating mills in the Center-South region.

However the traceability of the information and

the uniformity of procedures have not the same

level of accuracy as in the cases of the two

previous sets of documents.

In the cases where weather conditions can

have significant impacts on the results (such as the

case of sugar cane productivity) the averages for

five seasons in sequence (1998/99 to 2002/2003

seasons) have been used. In other cases, the 2001/

2002 harvesting season has been used as reference

for both agricultural and industrial performance data.
13

T

Systems and emission

flows definition

o evaluate the GHG emission mitigation in the

life cycle of ethanol produced from sugar cane,

the concept of “autonomous distillery” has

been adopted, meaning that the mill will

process the sugar cane to produce ethanol

only. In this way the effects of sugar production

can be ignored.

The mitigation corresponds to the

reduction of GHG emissions obtained by the

production and use of ethanol (substituting for

gasoline as a fuel). It is, therefore, the

difference between the emissions in a

situation where no ethanol is produced nor

used and a situation with the actual emissions

with ethanol: both of which situations reflect

Brazilian conditions.

For the life cycle analysis the

control volume used included the cane

production area, the distillery and the final

use of fuel ethanol.

To facilitate the calculations the

GHG emissions have been divided into

four groups.

Group 1:

Carbon flows associated with the uptake

of atmospheric carbon by photosynthesis

and its gradual release by oxidation.

1.a Uptake of atmospheric carbon

(photosynthesis);

1.b Carbon release during cane field burning,

before harvesting (around 80% of tops and

leaves are burned with an efficiency of 90%);

1.c Oxidation of unburned residues, in

the field;

1.d CO2 release in the fermentation of

sucrose to ethanol;

1.e CO2

 release by the combustion of all

bagasse, for power and heat generation, in

the boilers of the mills or in other industries

boilers (surplus bagasse);

1.f CO2

 release by the combustion of ethanol

in automobile engines.

These emission flows can be considered to be nearly neutral, for it is assumed

that all fixed carbon is released again within

the cycle of sugar cane production and the

final use of ethanol and bagasse. An exception

is the uptake of part of the carbon in the soil (in

past decades the cane fields showed a positive

average carbon uptake because land was

generally poor in organic matter before being used to

grow cane). In this study, due to the difficulties in

estimating with a minimum accuracy the level of

carbon fixed in the soil, this fraction has been ignored,

which results in a conservative assumption.

Thus, the net contribution of the Group 1 carbon

flows has been considered as zero which is a common

assumption for cycles of biomass production and use.

Group 3:

The GHG flows not associated with the use of fossil

fuels are mainly N2

O and methane; consideration

was given to:

3.a Release of other GHG (non CO2

) in the process

of cane field burning;

3.b Release of N2

O from the soil, due to fertilizer

decomposition;

3.c Release of other GHG (non CO2

) in the combustion of bagasse in steam boilers;

3.d Release of other GHG (non CO2

) in the combustion of ethanol in engines.

These are negative flows since they contribute

to emission increase.

These flows are also negative, that is, they

contribute to the increase of GHG emissions.

Group 2:

Carbon flows associated with the use of fossil fuels

in the production of all chemicals and inputs used

in the agricultural and industrial sectors for the

production of sugar cane and ethanol, as well as in

the manufacture of equipment, construction of

buildings and their maintenance:

2.a CO2

 release due to the use of fossil fuels in the

cane fields: tillage, irrigation, harvesting, transportation etc.;

2.b CO2 release due to the use of fossil fuels in the

production of agricultural inputs (seeds, herbicides,

pesticides, fertilizers, lime etc.);

2.c CO2 release due to the use of fossil fuels in the

production of agricultural equipment, spare parts

and their maintenance;

2.d CO2 release due to the use of fossil fuel for

industrial inputs (lime, sulfuric acid, biocides, lubricants etc.);

2.e CO2 release due to the use of fossil fuels in the

manufacture of equipment, construction of buildings, and their maintenance in the industrial area.
14

Group 4:

This group includes what can be called “virtual”

flows of GHG emissions; they would take place if,

in the absence of ethanol, the fuel demand was

met by gasoline and if in the absence of surplus

bagasse, fuel oil was used.

These emissions can be characterized as:

4.a GHG avoided emission by substituting ethanol

for gasoline;

4.b GHG avoided emission by substituting bagasse

for fuel oil in other industrial sectors.

In the analysis that follows, the flows of Groups

2 to 4 will be evaluated; the flows of Group 1 will not

be calculated since the net balance is zero. To facilitate

the understanding of some simplifying assumptions, it is

important to bear in mind that the emissions of Groups

2 and 3 are nearly ten times smaller than those of Group

4. This is normally true for fossil fuels or biomass systems

where the energy embodied in equipment and buildings

is small when the whole useful life is considered. The

same applies to the energy inputs for the manufacture

of chemicals and other materials used in the production

process. There are some exceptions such as the case

of ethanol from corn in the USA.
15

T

Level Energy consumption

Scenario 1 Scenario 2

 (kcal/TC) (kcal/TC)

Fuel

Agricultural operations/harvesting (A2)

Transportation (A3)

Level total

Fertilizers (A4)

Lime (A5)

Herbicide

Pesticides

Seeds (A6)

Level total

Equipment (A7)

Level total

Total

Table 1 – Energy consumption in sugar cane production

1

2

3

9,097

8,720

17,817

15,152

1,706

2,690

190

1,336

21,074

6,970

6,970

45,861

9,097

10,261

19,358

15,890

1,706

2,690

190

1,404

21,880

6,970

6,970

48,208

Emissions

he detailed analysis is presented in Annex

1. The three energy levels considered in

sugar cane production are:

Level 1 – Diesel oil used in agricultural

operations and sugar cane transportation.

Level 2 – Other inputs: fertilizers, lime,

herbicides, pesticides, seeds.

Level 3 – Energy for production and

maintenance of equipment and labor.

In Level 1, the energy consumption

associated to fuel (diesel) can be calculated

using the energy value of diesel (lower heating

value, LHV = 9,235 kcal/l plus 2,179 kcal/l for

production, transportation and processing) of

11,414 kcal/l. It should be pointed out that if the

objective of the analysis was just to verify the

fraction of self consumption of the same type of

energy in the ethanol production, without regard

to the life cycle, the diesel use should be

considered as its LHV value. For fuel oil the

energy values are equivalent to diesel5. Some

additional comments on these values can be

found in Annex 3, Note 1.

The summary of the results is

presented in Table 1. In this summary, no

distinction is made between the different

forms of energy (usually electric energy

is considered at its thermodynamic value,

that is, the thermal energy used in its

Use of fossil fuel in

sugar cane production

generation) but a complete discussion is presented

in Annex 3, Note 2.

Use of fossil fuel in the industrial

production of ethanol

The detailed analysis is shown in Annex 2.

In the industrial processing of sugar cane to

produce ethanol there are three items that should

be considered in the final energy balance:

Level 1 – Purchased electric energy, if any.

Level 2 – Energy required for the production of inputs

to the industrial process (chemicals, lubricants).

Level 3 – Energy for the manufacture of equipment,

construction of buildings and their maintenance.

Table 2 summarizes the results for the three levels

and two Scenarios without distinction between the

forms of energy (see Annex 3, Note 2).

It can be seen from the energy balance (Annex

2) that there is a surplus of energy being produced, in

the form of surplus bagasse that will be considered in

the overall analysis, amounting to 40,300 kcal/TC

(Scenario 1) or 75,600 kcal/TC (Scenario 2).

A comparison between the energy produced in the

process in the form of ethanol and surplus bagasse

and the fossil energy consumed is shown in Table

3. It can be seen that the output energy to input
16

Table 3 – Energy generation and consumption in the production of sugar cane and ethanol

Activity Energy consumption

Scenario 1 Scenario 2

(kcal/TC) (kcal/TC)

Sugar cane production (total)

Agricultural operations

Transportation

Fertilizers

Lime, herbicides, pesticides etc.

Seeds

Equipment

Ethanol production (total)

Electricity

Chemicals, lubricants

Buildings

Equipment

External energy flows Input Output Input Output

Agriculture 48,208 - 45,861 -

Factory 11,800 - 9,510 -

Ethanol produced - 459,100 - 490,100

Surplus bagasse - 40,300 - 75,600

Total 60,008 499,400 55,371 565,700

Output/input 8.3 10.2

48,208 45,861

9,097 9,097

10,261 8,720

15,890 15,152

4,586 4,586

1,404 1,336

6,970 6,970

11,800 9,510

0 0

1,520 1,520

2,860 2,220

7,420 5,770

energy ratio is 8 to 10, considerably larger than in the

case of ethanol from corn in the USA. The energy flows

in and out of the control volume of the agricultural and

industrial sectors are shown in Figure 1, for Scenario 1.

1

2

3

Table 2 – Energy consumption in the production of ethanol

Level Energy consumption

Scenario 1 Scenario 2

(kcal/TC) (kcal/TC)

Electric energy

Chemicals and lubricants (A9)

Buildings (A10)

Heavy equipment

Light equipment

Total

0

1,520

2,860

3,470

3,950

11,800

0

1,520

2,220

2,700

3,070

9,510
17

Figure 1 – Energy balance – Scenario 1 (Mcal/TC)

Agricultural area

(Sugar cane production)

Industrial area

(Processing of ethanol)

Surplus

bagasse

40.3

Ethanol

459.1

1 t cane

Fertilizer 15.9

Lime 1.7

Herbicides 2.7

Pesticides 0.2

Seeds 1.4

Manufacture/maintenance

equipment 7.0

Chemical

lubricants 1.5

Manufacture/maintenance

Buildings 2.9

Heavy equipment 3.5

Ligth equipment 4.0

Electric energy 0

Thermal energy 0 Solar energy

Agricultural operations 9.1

Transportation 10.3

(Renewable energy)/(Fossil lubricants) = 8.3

GHG emissions due to the use of fossil fuels

All fossil fuel use listed in Tables 1 and 2 has

been considered here, including direct and indirect

uses. The values of indirect uses of energy for fuels,

as well as the carbon emission coefficients for their

combustion, can be found in Annex 3, Note 2.

Diesel has been considered in the agricultural operations, cane harvesting and transportation and fuel oil for the production of

chemicals and the energy embodied in equipment,

buildings and their maintenance. This simplification is acceptable considering the structure

of the energy use in such applications and the small

magnitudes involved.

Total diesel oil consumption: 19,358 kcal/TC

and 17,817 kcal/TC, for Scenarios 1 and 2, respectively.

Total fuel oil consumption: 40,650 kcal/TC and

370,554 kcal/TC, for Scenarios 1 and 2, respectively.

The corresponding GHG emissions, as CO2

equivalent (CO2eq.), are: 19.2 and 17.7 kg CO2eq./

TC, for Scenarios 1 and 2, respectively.

Other GHG emissions in the production and use of ethanol

In this category are included the emissions

associated with sugar cane production, cane processing

for ethanol and final use of ethanol (as fuel) that are not

derived from use of fossil fuels. The most important are:

– Methane and N2

O emissions from the burning of sugar

cane trash before harvesting;

– N2

O soil emissions;

– Methane emissions from bagasse burning in boilers;

– Methane emissions from ethanol combustion in

vehicle engines, compared with those from gasoline

combustion.

Emissions from sugar cane trash burning in the field.

The calculation have been done considering

emission coefficients measured in a wind tunnel

simulating the cane field burning6

 and alternatively

the average values for agricultural residues

recommended by IPCC7

 (see Annex 3, Note 4).

The IPCC values led to higher emissions

values and, being on the conservative side, have

been adopted; the results for methane and N2O,

shown in detail in Annex 3, Note 4, are: 9.0 kg

CO2eq./TC

N2O soil emissions

Evaluations based on the use of nitrogen

fertilizers (Annex 3, Note 5) considered that for the

Center-South region conditions around 28 kg N/ha

are used in cane planting and 87 kg N/ha for each

ratoon, which gives an average value of 75 kg N/

(ha.year) for the whole cane cycle. Most of the

fertilizer used is of the NH4

 type.

The resulting emissions are 1.76 kg N2

O/

(ha.year). Since N2

O has a global warming potential

296 larger than CO2

, this results in 521 kg CO2eq./

(ha.year) or 6.3 kg CO2

eq./TC

Methane emissions from bagasse burning in boilers.

Significant unburned organic compound

emissions, including methane, in bagasse fired

boilers take place only during operational transients

or uncontrolled disturbances in the combustion
18

process. Because of almost continuous operation

during the crop season, which is the ethanol

production period, such transients and disturbances

are relatively small in the ethanol distilleries and

sugar mills, and this substantially reduces methane

emissions. Therefore, this type of emissions will be

ignored in this study.

Methane emissions from automotive engines fueled

with ethanol or gasoline/ethanol blends, compared

with those from pure gasoline engines.

It is shown in Annex 3, Note 6, that although

it is difficult to measure differences between

emissions from ethanol and gasoline engines (since

there are no engines in use in Brazil that operate on

ethanol-free gasoline), the technological evolution

of the engines fueled with ethanol and gasoline/

ethanol blends has made it possible for these engines

to meet current tight legal emission limits. It has also

brought the methane emissions to very low levels.

These values are very small when compared

with other items considered in this study. In Annex 3

the beneficial aspects of the use of ethanol in

automobile engines are also discussed.

Avoided emissions

GHG emissions are avoided by the use of

surplus bagasse as fuel in other industrial sectors,

substituting for fuel oil, as well as by the use of ethanol

as an automotive fuel, substituting for gasoline. In a near

future, a fraction of the bagasse produced (and the trash)

could be used to generate considerable amounts of

surplus electric energy or more ethanol, via hydrolysis,

contributing even more to reducing the GHG emissions.

Surplus bagasse

An analysis of the surplus bagasse situation is

presented in Annex 3, Note 7.

On average, 280 kg of bagasse/TC are

produced with a moisture content of around 50%. The

surplus is estimated as 8% in Scenario 1 and 15% in

Scenario 2; therefore, the energy corresponding to

these amounts of bagasse are 40,300 and 75,600 kcal/

TC, for Scenarios 1 and 2, respectively (see Annex 2).

To estimate the avoided emissions when this

bagasse is substituting for fuel oil, operating conditions

have been established for both bagasse and fuel oil

fired boilers. Under these conditions (see Annex 3,

Note 7), the 8% and 15% of surplus bagasse

correspond, in terms of end energy use, to 3.2 and 6.1

kg fuel oil/TC being displaced.

The total avoided emissions (including

indirect emissions) related to the fuel oil displaced

are 12.5 and 23.3 kg CO2eq./TC, for Scenarios 1

and 2, respectively.

Ethanol

Considering the average productivity and

efficiencies of the mills and distilleries, the total emissions

(direct and indirect) of the displaced gasoline (Annex 3,

Note 8) and the fuel equivalence of Brazilian automobile

engines, the avoided emissions due to the use of ethanol

were calculated for hydrous and anhydrous ethanol. The

details are presented in Annex 3, Note 8.

The resulting avoided emissions are:

2.82 kg CO2

/l anhydrous ethanol

1.97 kg CO2

/l hydrous ethanol

Referring to metric ton of cane, the figures are:

Anhydrous ethanol: 242.5 or 259 kg CO2

eq./TC, for

Scenarios 1 and 2, respectively

Hydrous ethanol: 169.4 or 180.8 kg CO2

eq./TC, for

Scenarios 1 and 2, respectively.

Balance of emissions and conclusions

The results presented above are summarized

in Table 4.

The values are alternative, which means that

242.5 kg CO2

eq./TC is avoided if anhydrous ethanol

is produced or 169.4 kg CO2eq./TC with the

production of hydrous ethanol.

For many applications it is more convenient

to have the emission data referred to as cubic meters

of ethanol (net value), whether it is anhydrous or

hydrous. The conversion can be done using the sugar

cane productivity of the two scenarios, leading to:

Anhydrous ethanol: 2.6 and 2.7 t CO2

eq./m3 ethanol,

for Scenarios 1 and 2 respectively

Hydrous ethanol: 1.7 and 1.9 t CO2

eq./m3 ethanol,

for Scenarios 1 and 2, respectively.

The values for Scenario 1 (current average),

should be preferred for GHG emissions evaluations

because they reflect realistic conditions.

Figure 2 shows the emission flows related

to the Agricultural Production, Industrial Processing

and Ethanol Bagasse Utilization control volumes

(Scenario 1).

Taking as a base case that Brazilian fuel

ethanol consumption is around 12 million m3

 per

year, in approximately equal shares of anhydrous and

hydrous ethanol, it can be estimated that the use of

ethanol as a fuel in Brazil reduces the GHG

emissions by 25.8 million t CO2

eq./year or 7.0 million

t Carbon eq./year.
19

Figure 2 – GHG (*) Emissions – Scenario 1 (kg CO2eq./TC)

Avoided emissions: 220.5 (anhydrous ethanol) ou 147.4 (hydrous ethanol) kg CO2eq./TC

(*) Photosynthesis cycle is not included since all carbon fixed by the cane is released as CO2 (bagasse burning, burning/oxidation of trash, ethanol burning, fermentation; except for a small fraction that is

fixed into the soil).

Agricultural area

(Cane production)

Industrial processing

(Ethanol production)

Utilization

Ethanol : Vehicles

Surplus bagasse : Industrial fuel Surplus

bagasse

Ethanol

1 t de cane

 CH4, cane burning 6.6

 N2O, from soil 6.3

 N2

O, cane burning 2.4

CH4

, boilers (~zero) CH4

 other

(~ zero with respect to gasoline)

Chemicals, etc. 7.1

Transportation and

agricultural operations 6.0

Chemicals, lubricants 0.5

Building, equipment 3.3

Electric and thermal energy (zero)

Surplus bagasse

substitution for fuel

oil: 12.5

Ethanol substitution for

gasoline: 242.5

(anhydrous)

or 169.4 (hydrous)

Equipment 2.3

(A): Anhydrous ethanol

(H): Hydrous ethanol

Table 4 – Ethanol life cycle emissions

(kg CO2eq./TC)

Scenario 1 Scenario 2

(average) (best values)

Type

Fossil fuels

Methane and N2

O from trash burning

Soil N2

O

Total emissions

Avoided emissions

Surplus bagasse use

Ethanol use

Total avoided emissions

Net avoided emissions

17.7

9.0

6.3

33.0

23.3

19.2

9.0

6.3

34.5

12.5

259.0 (A); 180.8 (H)

282.3 (A); 204.2 (H)

249.3 (A); 171.1 (H)

242.5 (A); 169.4 (H)

255.0 (A); 181.9 (H)

220.5 (A); 147.4 (H)
20

Annex 1 – Sugar

cane production

20

Mechanical harvest 35%

Manual harvest 65%

Burned sugar cane harvest 80%

Unburned cane harvest 20%

Type of harvest São Paulo (%) Center-South (%)

Manual 63.8 65.2

Mechanical 36.2 34.8

Burned sugar cane 75.0 79.1

Unburned sugar cane 25.0 20.9

Table 5 – Sugar cane yield (averages for harvest seasons 1998/99 to 2002/03)

Harvest Yield (t/ha)

1st – Plant cane (18 months)

Plant cane (12 months)

2nd – (1st ratoon) 90

3rd – (2nd ratoon) 78

4th – (3rd ratoon) 71

5th – (4th ratoon) 67

Average of 5 harvests 82.4 t/ha (68.7 t/ha.year)

 _ } Xweighed = 106

113 (80%)

77 (20%)

Introduction

The data used in this analysis refers to the year 2002 for the Copersucar associated mills.

In the present situation some of the basic parameters for harvest and sugarcane quality used were:

1. Sugar cane harvest – present situation8

Considering that approximately 85% of the Brazilian ethanol production occurs in the

Center-South, the following situation was assumed for Brazil:

For simplicity all the unburned cane harvested was considered to be mechanized harvest.

It is important to mention that this simplification results in a more conservative analysis.

These data were used to determine the necessary equipment for the agricultural operations.

2. Pol and Fiber

Considering the average of five consecutive harvest seasons (1998/99 to 2002/03) the

following data were obtained9

:

A1: Agricultural yield

The averages for various regions and sugar cane varieties (Copersucar Technology Center – CTC) are:

Average Pol % cane 14.53%

Average Fiber % cane 13.46%

Average age of plow out9

:

99/00 harvest season 5.13 harvests

00/01 harvest season 5.18 harvests

01/02 harvest season 5.33 harvests

Normally 5 harvests are carried out (average of 82.4 t/ha). The ratoons are cut after one

year and the plant cane two years after harvesting the previous ratoon for “18 month cane”.

Therefore the average for a full cycle of 5 harvests is 68.7 t/ha.year.
2121

A2: Agricultural operations and harvest

a) Agricultural operations

The agricultural operations, the equipment used and their capacities are listed in Table 6.

The data for Table 6 were obtained from the research and development database10.

The normal sequence for agricultural operations is given in Table 7.

Observations:

• The previous analysis of soil compaction permits the reduction of 30% in subsoiling area.

• The mechanical cultivation (ridge removal) is approximately 70% of the planted area

and is done after the chemical cultivation.

Annex 1 – Sugar cane production

Table 6 – Agricultural operations: equipment

No Equipment Power Implements Capacity Consumption

(cv) (ha/h) (l diesel/h)

1 MF 290 78 Lime distributing wagon 1.61 6.0

2 CAT D-6 165 Heavy harrow, 18 discs x 34" 1.30 27.6

3 CAT D-6 165 5 shanks subsoiler 1.00 26.0

4 CAT D-6 165 Heavy harrow, 18 discs x 34" 1.35 27.6

5 Valmet 1780 165 Light harrow, 48 discs x 20" 1.60 15.0

6 MF 680 170 2 row furrower – fertilizer 1.10 15.0

7 MF 275 69 Planting wagon 0.60 4.0

8 MF 275 69 2 row furrow coverer 1.80 4.8

9 MF 275 69 Herbicide pump 2.50 4.0

10 MF 292 104 Cultivator 1.30 8.0

11 MF 275 69 Trash rake 1.50 4.0

12 Valmet 1580 143 Triple cultivator 1.30 9.2

13 Valmet 1580 143 Mechanical ratoon eliminator 1.10 12.2

14 Case A7700 330 Combine sugar cane harvester 45.0 t/h 40.4

15 MF 290 RA 78 Sugar cane grab loader 46.0 t/h 7.1

16 MB 2318 180 Sugar cane transport (8%) 2.2 km/l -

17 MB 2325 250 Sugar cane transport (25%) 1.6 km/l -

18 Volvo 360 Sugar cane transport (67%) 1.2 km/l

19 MB 2318 180 Dumpster (skip tipper) truck 2.0 km/l -

20 MB 2213 130 Flat bed fertilizer transport 2.0 km/l -

21 MB 2318 180 Vinasse transport 2.2 km/l -

22 MB 2220 200 Vinasse transport 2.0 km/l -

23 Volvo 360 Vinasse transport 1.3 km/l -

24 Diesel pump 120 Vinasse application 120 m3

 /h 14.0

25 Valtra BH 180 180 Tractor hauler/transloader 35.0 t/h 9.0
2222

Equipment Operational capacity Specific consumption

(ha/h) (l/ha)

Case harvester 0.5461 74.0

Santal cane loader 0.5583 12.7

Tractor hauler/transloader 0.4248 21.2

Table 8 – Harvest equipment

Table 7 – Consumption of diesel oil in agricultural operations

Capacity Specific Fraction

No Agricultural operations Equip. consumption of area

 (ha/h) (l/ha) worked

Land preparation and planting operations (20% of total area)

1 Lime application 1 1.61 3.73 1.00

2 Mechanical elimination of ratoons 13 1.10 11.09 0.30

3 Chemical elimination of ratoons 9 2.50 1.60 0.30

4 Heavy harrowing I 2 1.30 21.23 0.90

5 Subsoiling 3 1.00 26.00 0.70

6 Heavy harrowing II 4 1.35 20.44 0.70

7 Heavy harrowing III 4 1.35 20.44 0.30

8 Light harrowing 5 1.60 9.38 0.90

9 Furrowing and fertilizing 6 1.10 13.64 1.00

10 Seed cane distribution 7 0.60 6.67 1.00

11 Closing furrows and insecticide application 8 1.80 2.67 1.00

12 Chemical tillage (herbicide application) 9 2.50 1.60 1.00

13 Mechanical tillage 10 1.30 6.15 0.70

Ratoon tillage operations (80% of total area)

1 Trash raking 11 1.50 2.67 0.25

2 Triple operation tillage 12 1.30 7.08 1.00

3 Chemical tillage (herbicide application) 9 2.50 1.60 0.85

The total consumption of energy in agricultural operations can be estimated based on Table 7.

The values for consumption in agricultural operations are equivalent for Scenarios 1 and 2:

Plant cane: Cp = 102.6 l/ha

Ratoon cane: Cr = 9.1 l/ha

b) Harvest

For the equipment 14, 15 and 25 (Table 6) and an average yield of 82.4 t/ha the results are shown in Table 8.

Annex 1 – Sugar cane production
2323

CAC(I/TC) = {0.17CP+0.67CS+0.83[0.35(CCC+ CTR)+0.65(CCM+ CTR)]}

1

PA

2

3

Single Truck = x x 1,000 = 30.3

1

2.2

l

km

1

15t

ml

l

ml

t.km

Double Wagon = x x 1,000 = 22.3

1

1.6

l

km

1

28t

ml

l

ml

t.km

The present situation can be described as:

In a 6 year cycle: one cane elimination, four ratoon crops and five harvests, 35% of which

mechanically (15% unburned and 20% burned) and 65% manually with mechanical grab loading are

effected8. The annual diesel oil consumption in agricultural operations and in harvesting is given by:

Here, CCC and CCM (l/ha) are the consumption in mechanical and manual harvesting

respectively. CTR is the consumption of the hauler tractors or transloaders and PA is the annual cane

yield, TC/(ha.year).

Observation: For manual harvesting, the transport of cane was considered to be made

by triple trailer trucks, which implies a participation of haulers in 2/3 of the total cane.

The results obtained are:

Scenarios 1 and 2: CAC = 0.797 l/TC

A3: Transportation

All the values for capacity and consumption are given in reference 9.

Sugar cane transportation from the field to the mill

The specific consumption values vary according to the type of truck and distance. The mean

harvested area distance is 20 km. Based on Table 6 and in the proportion of each type of truck

used in cane transport: Single truck (15 t) = 8%, Double wagon (28 t) = 25%, Triple wagon (45t)

= 67% it is estimated, for Scenario 1 the value of 20.4 l/t.km.

Calculations:

Annex 1 – Sugar cane production

Specific consumption = 40.4 x = 74.0 l/ha

Operational capacity = 45 x = 0.5461 ha/h

Santal Loader:

Operational capacity = 46.0 x = 0.5583 ha/h

Specific consumption = 7.10 x = 12.7 l/ha

Tractor hauler/transloader:

Operational capacity = 35.0 x = 0.4248 ha/h t

h

1

82.4

ha

t

Specific consumption = 9.0 x = 21.2 l/ha

Calculations:

Case Harvester

t

h

1

82.4

ha

t

l

h

1

0.5461

h

ha

t

h

1

82.4

ha

t

l

h

1

0.5582

h

ha

l

h

1

0.4248

h

ha
24

1

1.2

Triple Wagon = x x 1,000 = 18.5

l

km

1

45t

ml

l

ml

t.km

m3

ha Direct application with tanker trucks = x x 100 = 42.4 x 0.06 = 2.54

1

2.2

l

km

14 km

15 m3

l

ha

l

ha

Sprinkler system (channels + water cannons) = 16 x x 150 = 20 x 0.63 = 12.6

l

h

h

120 m3

m3

ha

l

ha

l

ha

Xweighed = 24.7

l

ha

–

Tanker truck + water cannons = x x 100 = 30.8 x 0.31 = 9.55

1

1.3

l

km

24 km

60 m3

m3

ha

l

ha

l

ha

Results: CTV = 24.7 l/ha

Four Wagon/58 t = x x 1,000 = 15.7

The use of trucks with a larger transport capacity decreases the values, as is the case with

the four Wagon Volvo FH (specific consumption= 15.7 ml/t.km) used as a reference in Scenario 2.

Results:

Scenario 1: CTC = 0.816 l/TC Scenario 2: CTC = 0.628 l/TC

Seed cane transportation

For the use of 12 t of seed cane/ha, at an average distance of 20 km, the MB2318

consumes CTM = 17.4 l/ha

Filter mud cake

Where filter mud cake is used, it is applied in 30% of the planted area. In the present

situation, only Scenario 2 considers the application of filter mud cake.

A dumpster truck (MB2213) with an average load of 8 t and a consumption of 2.5 km/l is

used for the application of filter mud cake in the fields; the average distance is 8km and the application

rate is 12 t (wet)/ha (5 t dry/ha).

Results: CTT = 9.6 l/ha

Vinasse

To be conservative, only Scenario 2 considers vinasse application in 30 % of the ratoon

area. The types of applications are:

Direct application with tanker trucks – 6% of the area – rate 100m3

/ha (MMB2318 truck with

15 m3 tank), average distance is 7 km;

Sprinkler (water cannons) system – 63% of the area – rate 150 m3

/ha (diesel pumps with channel);

Trucks combined with cannons – 31 % of the area – rate 100 m3/ha with Volvo Tanker (two 30

m3 tanks, distance up to 12 km.

Calculations:

Annex 1 – Sugar cane production

Truck with 12 t of load: 2.3 km/l x 40 =17.4 l/ha 1

2.3

Xweighed = 20.4

ml

t.km

–

1

1.1

l

km

1

58 t

ml

l

ml

t.km
25

Scenario 2: CT = CTC + {0.17CTM+0.7(0.83CTA) + 0.3 (0.17CTT + 0.67CTV)} = 0.764 l/TC 1

PA

Scenario 1: CT = CTC + {0.17CTM+0.83CTA} = 0.899 l/TC 1

PA

*areas with filter mud cake and vinasse application (30%).

Table 9 – Fertilizer applicaton

Plant cane Ratoon Total

 Scenario 1 500 kg/ha (6-24-24) 500 kg/ha (16-5-24) 2,500 kg/ha (in 6 years)

 Scenario 2* 400 kg/ha (0-125-200) 200 kg urea 1,200 kg/ha (in 6 years)

Fertilizers

For Scenario 2 it was considered a 30% reduction in area of fertilizer application due to

the use of vinasse and filter mud cake. Values used for calculations are found in Table 9.

Typically a MB2213 (cargo weight of 12 t, 2.5 km/l) is used. For an average distance of

20 km and a cycle of 6 years, we have:

Scenario 1: 2,500 kg fertilizer/ha, CTA = 3.33 l/ha

Scenario 2: 1,200 kg fertilizer/ha, CTA = 1.60 l/ha

The amount of fertilizers is calculated considering that, at present, only 30% of the area

can be treated with vinasse and filter mud cake.

The different consumptions can be associated with agricultural yields, leading the total

consumption in transport to:

A4: Fertilizers

There is a large variation in application rate due to different soil types. Average values

are listed in Table 10.

Scenario 1 represents the conventional fertilization, while Scenario 2 considers the use

of filter mud cake in plant cane and vinasse in ratoons.

Considering that only 30% of these areas can be treated, the final figures for the 2

scenarios are presented in Table 11 (page 26).

The specific energy costs are known5

.

Annex 1 – Sugar cane production

Macronutrient Rate (kg/ha)

Plant cane Ratoon

Scenario 1 Scenario 2* Scenario 1 Scenario 2*

Nitrogen – N 30 – 80 90

Phosphorus – P2O5 120 50 25 –

Potassium – K2O 120 80 120 –

Table 10 – Rate of fertilizer application

*areas with the application of filter mud cake and vinasse (30%).
2626

Nutrient Energy Energy/ha Energy/TC Total

 (kcal/kg) (Mcal/ha.year) (Mcal/TC) (Mcal/TC)

N 58.3 14,700 857.50 12.48

P2

O5 36.7 2,300 84.33 1.23 15.9

K2O 100.0 1,600 150.00 2.18

N 60.0 14,700 882.00 12.84

P2O5 8.3 2,300 19.17 0.28 13.4

K2O 13.3 1,600 21.33 0.31

Table 11 – Enery in fertilizers

Final results:

Present situation

Scenario 1: Ef = 15,890 kcal/TC

Scenario 2: Ef = 15,890 x 0.7 + 13,430 x 0.3 = 15,152 kcal/TC

A5: Lime, herbicides and insecticides

Lime

Application rate of 2,200 kg/ha in 6 year cycles; energy cost of lime in the field is 313.4 kcal/kg5.

Results:

Ec = 1,706 kcal/TC

Herbicides

As a reference the values for the 1996 study were maintained due to the lack of information

regarding the energy cost (kcal/kg) of specific herbicides (see Annex 3, Note 3).

Results:

Eh = 2,690 kcal/TC

Insecticides

In sugar cane, insecticides are used in the control of soil pests and leaf cutting ants. The

energy cost of previous studies was maintained for these controls (190 kcal/TC).

A6: Seed cane

The average consumption is of 12 t of seed cane per hectare for each cycle of 6 years, that is:

0.0299 TC/TC. Admitting that the procedures for the production of seed cane are essentially equivalent

to those for commercial cane, 3% global energy cost represents the equivalent for seed cane.

Scenario 1: 1,404 kcal/TC (= 3% X 46,804 kcal/TC)

Scenario 2: 1,336 kcal/TC (= 3% X 44,525 kcal/TC)

Annex 1 – Sugar cane production

Annual

rate of

application

(kg/ha.year)

With

vinasse and

mud cake

(30%, Scenario 2)

Conventional
2727

Equipment Mean density of use (kg/ha)

Tractors and harvesters 41.8

Implements 12.4

Trucks 82.4

Total 136.6

Table 12 – Use of agricultural equipment

Table 14 – Energy cost of equipment

Equipment

Tractors

Implements

Trucks

Energy of

material

(kcal/ha)

493,825

185,550

1,263,170

Production

energy

(kcal/ha)

113,043

25,495

270,631

Energy for

repairs

(kcal/ha)

180,240

65,213

309,828

Energy mat.

+ production

corrected for

useful life

(kcal/ha)

497,632

173,057

1,257,717

Total

energy

(kcal/ha)

677,872

238,269

1,567,545

Useful

life

(years)

5

8

5

Energy cost

(kcal/TC)

1,973

434

4,563

A7: Agricultural machines and equipment

The present situation is based on a survey of a typical Copersucar mill with the

results presented in Table 1210.

The method suggested by Pimentel5

 is used to calculate the energy cost associated with

equipment. Basically the hypotheses are:

1) Considering the energy incorporated in the materials (steel, tires) and the production and maintenance.

The incorporated energy is essentially in the steel (15,000 kcal/kg) and tires (20,500 kcal/kg). The

energy consumed for the production of the various equipments is evaluated by weight (excluding tires).

2) The energy for maintenance corresponds to 1/3 of the cumulative total repairs (ASAE5 estimates

the values for each class of equipment).

3) The useful life of the equipment corresponds to 82% of the total life (due to interruptions) and the

energy cost is calculated, per year, using these values. These hypotheses lead to the results in Table 13.

With the data for density of use, estimated useful life and the yield of sugar cane the

results presented in Table 14 are obtained.

Results for the present situation:

Ee

 = 6,970 kcal/TC

A8: Labor

For this study, the energy in labor is not considered as an energy cost and it is therefore

not included in the calculations. In the 1984 balance, the estimated value was 1,880 kcal/TC.

Currently it is certainly less than that due to the increase in mechanical harvesting.

Annex 1 – Sugar cane production

Table 13 – Energy for the production and maintenance of equipment

Energy

of the

material

(kcal/kg)

Energy of

production

(kcal/kg)

Total

accumulated

repairs (%)

Weight

of tires

(fraction of

total weight)

Energy of

repairs (fraction of

material energy +

production energy)

Equipment

Tractors 11,814 0.179 3,294 89.1 0.297

Implements 15,000 - 2,061 92.6 0.309

Trucks 15,000 steel 0.06 3,494 60.7 0.202

20,500 tires
28

Annex 2 – Use of energy in

the industrial processing of

cane to ethanol

28

Introduction

This work is an updating of the industrial area parameters used in a 1995 study for

Copersucar member mills. Reference 11 provided the values used to assess the industry

performance data; the values related to the 2001/29002 crushing season were selected as reference.

It is important to point out that these values compare very closely with the five year average of

the crushing seasons 1998/1999 through 2002/2003.

RS (reducing sugars) 0.545%

Mill extraction efficiency 96.2%

Juice treatment efficiency 99.2%

Sugar loss in cane washing 0.61%

Fermentation efficiency 91.1%

Distillation efficiency 99.6%

Industrial sector energy balance

The present situation of the ethanol production has been analyzed using efficiency and energy

consumption average values for Copersucar member mills. These values are important to determine the operating

equilibrium condition for the co-generation system used, and to verify the surplus and deficits of energy.

Specific consumptions per ton of processed sugar cane have not changed much in the conventional

areas of the mills. A few major changes due to new processes (such as the substitution of cyclohexane for

benzene as dehydration agent) have been considered. The effects of the more efficient technologies such

as bagasse gasification/gas turbine have not been evaluated, simply because they are not in use.

Industrial conversion efficiency

Based on a pol % cane = 14.538

 and the RS and efficiencies listed above, the following

conversion rates have been determined:

Scenario 1: 88.7 l/TC (anhydrous ethanol)

Scenario 2: 91.8 l/TC (anhydrous ethanol)

Although these values have been calculated based on performance data shown in Copersucar

Benchmark Program11, it would be reasonable to apply them to the sugar cane industry in the State of

São Paulo or even to the whole Center-South region. However, to be on the safe side in the energy and

CO2

 balances the conversion rate value of 86 l anhydrous ethanol/TC has been used for Scenario 1 as

representative of Brazilian sugar cane sector. This value is a weighed estimate of various specialists of

the sector who suggested 88 l anhydrous ethanol/TC for the Center-South region and 75 l anhydrous

ethanol/TC for the Northeast region (ethanol production can be divided as 85% in Center-South and

15% in the Northeast. For Scenario 2, the value of 91.8 l anhydrous ethanol/TC was maintained.

Accordingly, the values used in the energy/CO2 balance are:

Scenario 1: 86.0 l/TC (anhydrous alcohol)

Scenario 2: 91.8 l/TC (anhydrous alcohol)

Utilisation of electricity

The mills increased the internal production of electrical energy during the 2001/02

harvest11 (average generation: 16.83 kWh/TC; maximum: 29.13 kWh/TC). Consequently, bagasse

excess was reduced (average: 5.8%; maximum: 17%). Mills exist with large excesses and

complete electricity self-sufficiency.

The average electricity consumption was 12.90 kWh/TC and the minimum, 9.64 kWh/TC.

Electricity bought (average) was 0.26 kWh/TC, which indicates 98% self-sufficiency.

On the other hand, the average sale of electric power was 5.86 kWh/TC (maximum: 16.98 kWh/

TC). These statistics refer to 2001/200211 crop season.

It follows that the hypothesis of the totality of the mills on average neither acquiring nor

exporting electricity is no longer absolutely valid: there is in fact an increase in energy export

(though relatively unimportant in the context of its potential).
2929

Annex 2 – Use of energy in the industrial processing of cane to ethanol

Scenario 1:

Surplus bagasse 8% 40,300 kcal/TC

External electric energy 0 0

Scenario 2:

Surplus bagasse 15% 75,600 kcal/TC

External electric energy 0 0

Table 15 – Surplus bagasse energy

There are two methods of evaluating (to evaluate emissions) the mills’ exports of electricity

(still incipient): we either consider the export to be small, and compute its value as mitigation

of emission and consider the resulting real bagasse excess, or we consider only the excess

bagasse (conservatively). As the excess statistics refer to the joint production of sugar and ethanol

(it being currently unrealistic to separate them), the securest option is the conservative one,

though adopting a slightly higher average figure (in the production of ethanol, the bagasse

excesses are larger than for sugar).

Thus, the values used for excess electricity are zero and from 8% (average) to 15%

(maximum) for surplus bagasse (see commentaries in the following section).

Energy used in milling sugar cane

An estimate of consumption can be made from the installed capacity together with some

observations of milling conditions, in some mills. The bigger mills have on the average a lower installed

specific power capacity (22.1 cv/TC for mills with milling capacity of over 300 tons of sugar cane per

hour - TCH). As in general they also have better cane preparation it is to be expected that the actual

power used would be very close to that installed. Although minimum values of 17 cv/TCH (installed

power) were identified, analysis of the whole sector shows that an average value of 20 cv/TCH is a

good estimate of the power actually used in the mills with good cane preparation and milling. The

relationship between power used in milling and in preparation is approximately 1.5.

Energy consumption in the processes: sugar and ethanol

The conditions found in the Brazilian mills make it difficult to analyze “average” values due to the

variations in the sugar/ethanol production ratios and the diversity of operating procedures in ethanol production,

as well as the differences in levels of energy conservation. Techniques to reduce energy consumption in sugar

production have been established and used for many years. In Brazil today the simultaneous production of

sugar and alcohol makes the sugar production easier, since it is not necessary to exhaust the molasses.

The potential to increase the production of surplus bagasse (or electric energy) has been

analyzed and the results are impressive. However, for the objective of this work only two Scenarios

have been considered, the first with the present average values and the second with the best

values achieved today.

For the sugar/ethanol mills, the values considered today are still:

– Average surplus bagasse of 5%, reaching 15% in the best cases;

– No outside electric power needed, for an average power consumption of 12.9 kWh/TC. (Most

mills are self sufficient in energy).

It is quite reasonable to assume that for the production of ethanol only (autonomous distillery) a

higher percentage of surplus bagasse can be obtained; therefore 8% is assumed as average value and

15% as best value.

With an average fiber content of 13.5% and a bagasse with 50% moisture content, 280

kg of bagasse with a LHV = 1800 kcal/kg is obtained. A summary of the bagasse and electric

power situation is shown in Table 15.

A9: Chemicals and materials for industrial sector

The main chemicals and lubricants used in the ethanol industrial production process are listed in Table

16, with the corresponding average utilization and associated energy consumption. These averages

refer to the 2002/2003 crushing season but they reflect well the averages for the last five years11.
3030

A10: Buildings, equipment and installations of the industrial sector

The evaluation of the energy used in the construction and erection of an ethanol distillery can

be done in a simplified way for the objective of this study, because it does not represent a

significant fraction of the energy flows involved in the ethanol production. This energy is used in

the construction of buildings, working areas and in the fabrication and erection of industrial

equipment.For this evaluation, an ethanol distillery with a nominal capacity of 120,000 l/day,

operating 180 days per year was used as reference.The energy embodied in the building and

working areas is detailed in Table 175

.

Table 18 – Energy in equipment fabrication

Weight (t) Total energy (109 kcal) Notes

Cane belt conveyor (30 m) 45 0.75 (c)

Bagasse belt conveyor (200 m) 180 3.9 (c)

Cane feed table and acessories 42 0.70 (c)

30”x54” mills tandem, 5 mills 220 6.16 (d)

Turbine, turbine generator, speed reducing train 50 0.9

Boilers 310 4.34 (e)

Distillery

– Stainless steel 76 1.67 (f)

– Carbon steel 400 6.64 (g)

Total 24.16

Annex 2 – Use of energy in the industrial processing of cane to ethanol

Item Consumption Energy (kcal/TC)

Sulfuric acid 9.05 g/l 740

Cyclohexane 0.60 kg/m3 anhydrous 130

Sodium hydroxide – 180

Lubricants 13.37 g/TC 170

Lime 930 g/TC 300

Total – 1,520

Table 16 – Energy in the chemicals and lubricants used in the industrial sector

Table 17 – Energy in the buildings and working areas

Area (m2

) Energy used Total energy

(106 kcal/m2

) (a) (109 kcal)

Industrial buildings 5,000 2.7 13.50

Offices 300 4.5 1.35

Repair shops, laboratories 1,500 1.7 2.55

Storage 4,000 0.5 2.00

Total 19.40

There are large variations in the industrial equipment installed in the various mills; a

typical case has been used as reference. The results are shown in Table 18.
3131

Energy cost (kcal/kg) Note

Forged steel 28,000 Finished product

Structural steel 16,600 Finished product

Turbine generator 9,500 Fabrication only

Tractor 14,350 Finished product

Combine 13,160 Finished product

Stainless steel (pipes, vessels) 16,200 to 22,000 Finished product

Table 20 – Energy cost for different equipment and materials

Annex 2 – Use of energy in the industrial processing of cane to ethanol

It must be pointed out that for each piece of equipment there are two components in the energy cost:

the energy required for the production of the raw material (steel, iron) and the energy required to manufacture the

equipment (b). From Tables 17 and 18, the total energy necessary for the installation of the industrial sector can

be estimated as 43x109 kcal. An analysis of this set of equipment has shown that some of the main equipment

(mill tandem and distillery) have a processing capacity adequate for 180,000 l ethanol/day.

The useful lives of the items in Table 17 and 18 have been assumed as:

Buildings: 50 years

Heavy equipment (mills, boilers): 25 years

Light equipment: 10 years

For maintenance, the energy cost has been considered as 4%/year of the total cost. With these

assumptions the specific energy costs per ton of cane (TC) can be estimated. Table 19 presents the results.

Table 19 – Energy use related to equipment and buildings in the industrial area

Total

energy

(109

 kcal)

Useful

life

(years)

Energy/

year

(109 kcal)

Energy/year

(maintain)

(109 kcal)

Total energy

(109

 kcal/year)

kcal/(TC/year)

 Scenario Scenario

 1 2

Buildings 19.40 50 0.348 0.696 1,044 2,860 2,221

Heavy equipment 15.85 25 0.634 0.634 1,268 3,474 2,698

Light equipment 10.31 10 1,031 0.412 1,443 3,953 3,070

Total 3,755 10,290 7,989

For the best case condition (Scenario 2) the operating conditions of several good distilleries have

been evaluated. The most energy efficient have indicated that the same equipment considered in the

tables above for the typical mill, with minor modifications, could produce 240,000 l anhydrous ethanol/day.

Adopting these values leads to the following results:

Scenario 1: 180,000 l/day and 377,000 TC/year

Equipment energy use: 10,290 kcal/TC

Scenario 2: 240,000 l/day and 470,000 TC/year

Equipment energy use: 7,989 kcal/TC

Notes:

a) Data from Hannon12.

b) The energy necessary to produce raw steel varies according to the process used. A summary of data collected

from many sources13 (P.F. Chapman, The energy cost of materials, Energy Policy, March, 1975) shows a variation

from 9,000 kcal/kg to 14,300 kcal/kg for six independent studies in the 70’s. In this work the value of 9,030 kcal/

kg has been used (Statistical Year Book, 197214). Values for the finished product (including the energy for

equipment fabrication) can be estimated based on the available data15.

c) Essentially structural steel.

d) In this case, the mill capacity is larger than required by the factory. It has been considered as forged steel to

estimate the energy cost.

e) Values estimated for “tractors and combines”. It could be one 65 t steam/h boiler or two 45 t steam/h boilers.

f) A,B,C,P columns; condensers; k heat exchanger.

g) Conventional distillery with wine and water tanks, condensers at 25 m height; fermentation vats, tanks,

piping, cooling coils (carbon steel) structures.This distillery had a nominal capacity of 120,000 l/day but could

reach, with minor improvements, 240,000 l/day of anhydrous ethanol.
32

Annex 3 – Notes and

supplementary data

32

Table 21 – Fossil fuel emissions

Density LHV

(kg/l) (MJ/kg)

Gasoline 0.742 44.8 18.9 846 776

Diesel 0.852 42.7 20.2 862 908

Fuel oil 1.013 40.19 21.1 848 1,061

Direct carbon

IPCC – 2001

(kg C/GJ)

Direct

emissions

(kg C/t)

Total emissions

(kg C/m3

)

Note 1: Life cycle CO2 emissions of fossil fuels used (or replaced) by sugar cane products

(ethanol and bagasse).

The analysis includes not only the direct emissions (such as CO2 emissions per liter of

diesel used in the agricultural operations) but also the indirect emissions (emissions in oil extraction,

its transportation to the refinery, refining, transportation to the consumers, evaporation). For petroleum

derived fuels the indirect emissions represent between 10 to 20% of the total emissions.

There are variations in the values of indirect emissions due to several factors: differences

in transportation distances and means (ships, pipeline, trucks), refining process and refining profile.

However, it is reasonable to use the simplifying assumption that the total emission of the

petroleum cycle is equally divided among the products, with respect to the corresponding LHV.

An example is shown in16 for diesel:

Indirect emissions (kg CO2/kg diesel)

Extraction and transportation of oil 0.06

Refining 0.16 – 0.26

Transportation to consumers 0.02

Evaporation 0.25 – 0.35

Direct emissions 3.15

Total emissions 3.40 – 3.49

Therefore in this case, the indirect emissions are 9% of the direct emissions.

In a classic reference in the 80’s, Pimentel5

 indicated that the direct fuel energy is 81%

of the total energy; the same value applying for gasoline, diesel and fuel oil.

Gasoline: + =

Diesel, fuel oil: + =

Direct (kcal/l)

8,179

9,235

Indirect (kcal/l)

1,930

2,179

Total(kcal/l)

 10,109

 11,414

For Brazil, some important points should be considered such as oil extraction technology

(most of the oil comes from deep water), oil type (mostly heavy oil) which may result in a higher

energy consumption for extraction and refining.

In this study, the 81% value for the direct energy has been used in conjunction with the

heating values and densities presented in BEN 200217. For the carbon content the IPCC7 values

have been used. Table 21 presents the main results.

Note 2: Forms of energy used in the production of agricultural and industrial chemicals and

materials, and embodied in equipment, buildings and structures

Energies embodied in the manufacture of equipment (field and industry) and construction of

buildings/structures are, as expected, small compared to the energy flows in the systems dedicated to

energy generation. They can, therefore, be estimated in a simplified way based on the weight and type
3333

of material used in the equipment (steel, iron, aluminum) and in some cases, such as tractors and

trucks, with some specific considerations. For buildings and others facilities the estimate is made

based on the covered area and type of construction (warehouse, office).

The tables used show the total energy value (kcal/kg of material, for example); in these

values are included the direct use of thermal energy (heat, transportation fuel) and the

thermodynamic equivalent of electric energy (in general, converted using the thermal efficiency

of the local thermal power plants). Thus, the CO2 equivalent emissions are estimated based on

the fuels used (fuel oil, natural gas, mineral coal), including electric energy. To identify the

fraction corresponding to electric energy it is necessary to investigate to what extent electric

energy is used in all involved sectors in Brazil.

To estimate the emissions, it would be adequate in the case of Brazil to separate electric

energy from others types of energy since today more than 90% of the country’s electric power comes

from hydro power plants (with nearly zero GHG emissions). It is important to notice that many sectors

involved (steel, iron) generate most of the electric energy they need, partly in a renewable way.

In any case, the values are small. BEN-200217 provides data to establish the following: (electric

power has a thermal energy equivalent of 1 kWh = 3,132 kcal for fuel oil fired thermal power plants):

– Mining/pelletizing sector

Electric energy: 60%; thermal energy: 40% (fuel oil, coal, NG, diesel)

– Iron/steel sector:

Electric energy: 25%; thermal energy: 75% (charcoal, coke, mineral coal, others).

Renewable energy: around 25%

– Steel alloy sector:

Electric energy: 75%; thermal energy: 25% (charcoal, wood, others)

Renewable thermal energy: around 85%

– Cement sector

Electric energy: 31%; thermal energy: 69% (fuel oil, coal, diesel, others)

Renewable thermal energy: around 5%

– Ceramics sector

Electric energy: 23%; thermal energy: 67% (wood, LPG, fuel oil)

Renewable thermal energy: around 60%

Considering the relative participation of each sector above, the participation of each type

of energy in the manufacture of equipment and construction of buildings can be estimated as:

Buildings/constructions

Electric energy: 30%; thermal energy: 70%

Equipment

Electric energy: 30%; thermal energy: 70%.

It must be understood that electric energy has been converted in equivalent thermal energy

(1 kWh = 3,142 kcal) and that in the mining, iron and steel sectors there is a lot of co-generation

involved. This separation of types of energy is considered for information only and isroughly estimated.

For the emissions balance all the energy involved in this section has been assumed as thermal

energy derived from fossil fuels (an important fraction of renewable energy has been ignored).

In the production of chemicals, for agriculture and industry, thermal energy is the major

part of the total energy. For instance, for ammonia, electric energy participation is only 1%.

In the Brazilian case, where more than 90% of electricity comes from hydro power

plants, to consider the total energy cost of chemicals as being from thermal origin is the

conservative assumption used is this study.

Note 3: Energy in the production of herbicides and pesticides

It is difficult to define values for this item since the products are frequently changing

and there is little information about energy use in the production process. This area in

Brazil has inclined to develop biological controls (as in the cases of cane borer and

froghopper) with a significant reduction in the use of pesticides.

Data from the 80’s for the herbicides and pesticides used in cane fields indicate that (6):

herbicides averaged 99,910 kcal/kg and insecticides averaged 86,000 kcal/kg.

Annex 3 – Notes and supplementary data
3434

Table 22 – Methane emissions from cane field burning

GWP–100

IPCC7 2.83 0.101 0.286 23 6.6

Jenkins6 0.41 0.101 0.041 23 0.94

Emission coefficient

(kg CH4

/t trash)

Emission

(kg CO2

eq./TC)

Trash burned

(t trash/TC)

(*)

Emissions

(kg CH4/TC)

(*) 140 kg (DM) of trash/TC, with 82.4 TC/ha; 80% of cane burned with an efficiency of 90% (incomplete burning)

Based on these energy values and product consumption of the mid 90’s, the emission values

have been estimated and considered to be very small.

Note 4: Methane emissions from trash burning, before harvest

There is only one complete study covering methane emissions from the trash (cane

leaves) burning before the cane harvest. This study developed an adequate methodology and

simulated trash burning conditions in a wind tunnel in 19946

. IPCC7 recommends the use of

generic values for the emissions from the burning of agricultural residues when specific data are

not available; because these values are substantially higher than those presented in reference6

,

the IPCC7

 values for GWP-100 are used to convert in CO2 equivalent emissions.

Table 22 presents the results for both reference6 and IPCC7.

To maintain a conservative position, the IPCC values have been used, leading to 6.6 kg CO2eq./TC.

The N2

O emissions from trash burning can be estimated using IPCC (7) values for agricultural

residues burning in general, as follows:

Residue carbon content:

0.50 kg C/kg residue (DM)

Residue nitrogen content:

N/C = 0.010 – 0.020

N2

O emission coefficient:

0.007 kg N/kg N in the residue

Considering 0.101 t trash/TC and assuming N/C = 0.15, results:

Carbon in the trash = 0.50 kg C/kg trash x 0.101 kg trash/TC = 50 kg C/TC

Nitrogen content in the trash = 0.015 x 50 = 0.75 kg N/TC

N2

O emissions = 0.75 kg N (trash)/TC x 0.007 kg N/kg N (trash) = 0.00525 kg N/TC = 0.00825 kg N2O/TC

Using IPCC value for GWP – 100 = 296, the CO2 equivalent is N2O emissions = 2.4 kg CO2eq./TC

Therefore, the total GHG emissions due to trash burning before harvest is 9.0 kg CO2

eq./TC.

Note 5: N2O soil emissions (nitrogen fertilizer)

Although there are not many studies available on N2

O soil emissions, the value for

sugar cane culture can be estimated using some assumptions18:

1. N2

O emissions depend on the quantity of nitrogen fertilizer used, the application technology

(NO3 or NH4) and soil conditions.

2. The emissions amount to 0.5% to 1.5% (in weight N/N) of the fertilizer used; the higher

values refer to NH4 type.

For the Center-South region in Brazil, around 28 kg N/ha is used during cane

planting and 87kgN/ha for each ratoon, resulting in 75 kg N/ha year for the whole cycle.

Most of the fertilizers used is of the NH4 type.

The resulting N2O emissions are therefore 1.76 kg N2O/ha year which is equivalent to

521 kg CO2eq./ha.year or 6.3 kg CO2eq./TC.

Annex 3 – Notes and supplementary data
3535

Note 6: Methane emissions from automotive engines fueled with ethanol, in comparison

with gasoline fueled engines.

From 1980 to 1996 the regulated emission limits for automotive engines were changed

considerably, in two phases (1986 and 1992)19. The analysis of the average emissions from 1986

and 1992 shows that carbon monoxide (CO) emissions have always been lower in ethanol

engines compared with gasohol engines (gasoline/ethanol blends). In this same period, NOx

emissions were similar in both cases and the organic compound emissions, expressed as

hydrocarbons (HC), were similar or lower. Based on the lower CO emissions it can be said that

the use of ethanol in automotive engines is beneficial in terms of reducing GHG emissions since

CO is a gas with indirect effect in the formation of GHG (can be oxidized to CO2 or participate

in the generation of ozone, which is also GHG). With respect to HC and NOx, the combination

of these gases results in the formation of ozone. However, there are no consistent studies in

Brazil that would allow the conclusion that the use of ethanol has had the beneficial effect of

reducing ozone in the lower atmosphere, although there are indications in the literature20 that

this may be true. One fact that favors this line of reasoning is that in USA, ethanol is one of the

oxygenates used in the production of Reformulated Gasoline, that has as the main objectives

the reduction of toxic emissions and the reduction of ozone formation. In spite of the referred

indication of positive impacts it has been decided not to claim any benefit in this area from the

use of ethanol in cars.

One point that deserves attention is the characterization of the HC’s formed in

the combustion process, especially with respect to the presence of CH4. It is known that

the mass ratio CO2/CH4 for internal combustion engines is, typically, around 4,700 for

gasoline and diesel and around 3,900 for methanol and ethanol21,23 which permits the

statement that the relative importance of methane emission is very small, even considering

its GWP = 23.

Data from Cetesb22 show that with the different technologies existing in 1993, the

ratio ethanol/HC in ethanol engines was in the range of 0.70 to 0.85, and the non ethanol

HC’s emissions were around 0.6 g/km. Assuming that 30% of HC is methane, the result

would be 15 kg CO2eq./m3 ethanol. Using a similar reasoning for the gasohol engine

emissions, the result would be no higher than 3.75 kg CO2eq./m3 ethanol (for 25% ethanol

in the gasohol). These figures represent less than 1% of the avoided emissions which can

be considered to be negligible.

It is very difficult to compare methane emissions from ethanol and gasoline engines in

Brazil since there are no engines in the country that operate on pure gasoline.

For today’s technology (electronic engine management, multipoint fuel injection, 3-

way catalysts) in use since 1997 due to the introduction of tighter emission limits, methane

emission level is 0.05 g/km 23. If this level is reached, the emission would be no higher than 0.9

kg CO2eq./TC, thus, still negligible.

Due to the above reasons automotive methane emissions are not included in the

CO2 balance.

Note 7: Use of surplus bagasse substituting for fuel oil in other industries (orange juice, pulp and paper)

It has been shown that an average of 280 kg bagasse/TC, with 50% moisture content is

produced in cane milling. The LHV is 1,800 kcal/kg and the HHV is 2,260 kcal/kg.

The estimated surpluses are 8% and 15% for Scenarios 1 and 2, respectively;

accordingly, the energy of this surplus bagasse is 40,300 and 75,600 kcal/TC for Scenarios 1

and 2, respectively (see Annex 2).

To estimate the avoided emissions when this surplus bagasse displaces fuel oil, the

following operating conditions are assumed for the two systems:

Bagasse: boiler average efficiency of 78.7% (LHV) and 10% losses to account for fuel

conditioning, start ups and shut downs.

Fuel oil: boiler efficiency of 92% (LHV); LHV = 49.19 MJ/kg under these conditions the 8%

and 15% surplus bagasse would correspond, in terms of final energy use, to 3.2 and 6.1 kg of

fuel oil/TC, displaced.

The total emissions, including the indirect ones, related to these amounts of fuel oil are

12.5 and 23.3 kg CO2

eq./TC, for Scenarios 1 and 2, respectively.

Annex 3 – Notes and supplementary data
3636

Note 8: Use of ethanol, substituting for gasoline, in E-100 engines (hydrous ethanol) and gasoline/

ethanol blend engines (anhydrous ethanol).

Scenario 1: 86.0 l anhydrous ethanol/TC

Scenario 2: 91.8 l anhydrous ethanol/TC

With the same amount of cane, the production of hydrous ethanol is approximately 3% larger.

The gasoline direct CO2 emissions, calculated from the Brazilian data (density =

0.742 kg/l; LHV = 44.8 MJ/kg and IPCC emission data (Annex 3, Note 1: 18.9 kg CO2/GJ,

LHV), are 628 g carbon/m3

. Adding the indirect emissions5 (Annex 3, Note 1), the total value

to be considered is 0.77 kg C/l or 2.82 kg CO2

/l gasoline.

Although a direct comparison between ethanol, gasohol and gasoline engines in Brazil

is not possible, the equivalence that is widely accepted today, as a function of the relative

performance of new vehicles, is as follows:

1 l of hydrous ethanol (E-100 engine) = 0.7 l of gasoline

1 l of anhydrous ethanol (E-25 engine) = 1 l of gasoline

Under these conditions, the avoided emissions are:

2.82 kg CO2/l anhydrous ethanol

1.97 kg CO2

/l hydrous ethanol

or referring to sugar cane production:

Anhydrous ethanol: 242.5 or 259 kg CO2

/TC, for Scenarios 1 and 2, respectively.

Hydrous ethanol: 169 or 181 kg CO2/TC, for Scenarios 1 and 2, respectively.

Annex 3 – Notes and supplementary data
37

References

1. Macedo, I. C. e Nogueira, L. A. H. Balanço de energia na produção de cana-de-açúcar e álcool

nas usinas cooperadas. Boletim Técnico Copersucar – BTC no 31/85, Julho 1985, 22-33.

2. Centro de Tecnologia Copersucar (CTC), RLT-018 – Atividade 5.51 – Energy Balance/CO2

 Emission,

Março 1998.

3. Macedo, I. C. The sugar cane agro-industry – its contribution to reducing CO2

 emissions in Brazil,

Biomass and Bioenergy. 1992, (3), 77-80.

4. Macedo, I. C. Greenhouse gas emissons and energy balances in bio-ethanol production and use in

Brazil (1996). 1998, 14 (1), 77-81.

5. Pimentel, D. Handbook of energy utilization in agriculture. CRC Press, 1980.

6. Jenkins, B Atmospheric pollutant emission factor from open burning of sugar cane by wind tunnel

simulation – Final Report. University of California, Davis, 1994.

7. IPCC: Climate Change 2001: The Scientific Basis.

8. Centro de Tecnologia Copersucar (CTC), Programa de Acompanhamento Mensal de Performance

Agrícola (PAMPA) – Safra 2003/2004.

9. Centro de Tecnologia Copersucar (CTC), Controle Mútuo Agrícola Anual – Safras 1998/1999, 1999/

2000, 2000/2001, 2001/2002, 2002/2003.

10. Centro de Tecnologia Copersucar (CTC), Relatório C.428.00266 – Capacidade operacional e

eficiência de equipamentos, 2002.

11. Centro de Tecnologia Copersucar (CTC), Controle Mútuo Industrial – Safras 1998/1999, 1999/2000,

2000/2001, 2001/2002, 2002/2003.

12. Hannon, B. Energy and labor in construction sector. CAC Doc. 228, Center for Advanced

Computation, University of Illinois, Urbana, 1977.

13. Chapman, P. F The energy cost of materials. Energy Policy, Março 1975.

14. ONU. Anuário Estatístico da ONU, 1972.

15. Galliland, A. Science. Setembro 1975.

16. Rheinhard, G. A. Energie und CO2

 Bilanzierung Nachwachsender Rohstoffe. Vieweg, 1992.

17. Balanço Energético Nacional – BEN 2002 – Ministério de Minas e Energia (MME), 2002.

18. Lewandowski, I CO2

 balance for the cultivation of miscanthus, Biomass and Bionergy, 1995. 8

(2), 81-90.

19. Companhia de Tecnologia de Saneamento Ambiental – São Paulo (Cetesb), Relatório da Qualidade

do Ar – 2002. São Paulo, Agosto de 2003.

20. Brandberg, A. Unregulated Emissions from Engines Fueled with Alcohols and Other Fuels,

Proceedings of the IX International Symposium on Alcohol Fuels Florence, Italy, November

12 - 15, 1991.

21. Hirai, E. Y. Determinação de concentração de álcool nos gases de escapamentos de veículos leves,

Relatório Interno, Cetesb, São Paulo, Março 1993.

22. Branco, G.M. Controle de poluição veicular no Brasil, Relatório Interno, Cetesb, São Paulo,

Março 1992.

23. Unpublished information from automotive manufactures in Brazil.