Economy & Energy
Year IX -No 60:
February 2006 - March  2007 
ISSN 1518-2932

seta.gif (5908 bytes)No 60 Em Português  

SEARCH

MAIL

Data

DOWNLOAD

other e&e issues

 e&e No 60

Support:

 

Main Page

Agreement Letter signed by  e&e – OSCIP, MCT and PNUD, for Evaluating Emissions Associated with the Greenhouse Effect

Analysis of Specific Problems Related to Emissions that Generate the Greenhouse Effect

http://ecen.com

e&e links

 

 

Text for Discussion:

Analysis of Specific Problems Related to Emissions that Generate the Greenhouse Effect Detected by the Carbon Balance and in the Comparison with Other Emission Studies

 

 

Summary

 1 – Introduction

2 –Background

3 – Corrections in the Calculation of Emissions from Renewable and Non-Renewable Sources                          

4 – Treatment of Transformation Centers                    

4.1 Carbon Balance in Petroleum Refineries                 

4.2 Carbon Balance in Natural Gas Plants                   

4.3 Carbon Balance in Coking Plants                          

4.4 Carbon Balance in Gasification Plants                  

4.5 Carbon Balance in Alcohol Distilleries                    

4.6 Carbon Balance in Charcoal Plants                         

5 – Conclusion                                                                      

1 – Introduction

This study surveys the data for the revision of the Carbon Balance, object of the Partnership Contract 13.0020.00/2005 signed between the Economy – e&e – Organization and the Ministry of Science and Technology – MCT.

The present article is specifically related to Goal 3 whose proposed activity is the analysis of problems concerning emissions of greenhouse effect gases detected by the carbon balance and other studies conducted by the CGMCT. It is also connected with Goal 5 since it was used a more complete version of the software under development.

The following specific problems are examined:

a – Problems regarding the inclusion of renewable and non-renewable fuels in the “Other Recoveries” item;

b – Problems detected in carbon balance in Transformation Centers.

Based on these corrections, the C and CO2 emissions are calculated in the energy use and transformation in Brazil using the  bal_eec. Software. This software consolidates the carbon balance and emissions calculations previously carried out by ben_eec and benemis_e[1].

2 - Background

The methodology used is to account for the primary and secondary fuels that enter in the economic system of a country to satisfy needs generated by human activities (even the non-commercial ones) and the carbon mass that leaves the system. Once introduced in the national economy, the carbon contained in a fossil fuel is emitted to the atmosphere or is retained in some way, for example, in the fuel stock increase, its transformation into a non-energy product or its partial non-oxidized retention in the combustion residues.   

 Report 1 has presented a revision of the technical basis of the Project and of the chronogram (due to the delay involving the transfer of resources) and the following Technical Notes.

1 - Technical Notes № 1: Evaluation of Emissions Using the Extended Top-Down Process for the 1970 - 2004 Period (Goal 1). Published in the Nº 58 issue of this periodical.

2 - Technical Notes № 2: Carbon Content in Biomass Fuel

(Goal 3). Published in the Nº 57 issue of this periodical.

 3 - Technical Notes № 3: BEN_EEC Program – User’s Manual

 (Goal 5).

In the Carbon Balance calculation carried out in the ambit of the No 01.0065.00-2003 Agreement between e&e and MCT some differences were detected regarding the Extended Top-Down and Bottom – Up approaches and this is the object of the present study. Some differences were also detected between the Carbon Balance and the Initial Inventory of the MCT. Some of them correspond to the difference regarding the inclusion of renewable and non-renewable emissions in the Other Recoveries item.

The Other Recoveries item represented in 2005, 5.2% of the quantity involved in the transformation of primary into secondary energy and 0.8% of the final consumption in terms of carbon mass. That is, even though important from the methodological [2] point of view, it is expected that the corrections to be introduced in the present situation will not have an important impact on emissions calculations.

The differences found in the transformation centers are more significant in terms of emissions (14% of the carbon mass emitted in 2005) and are also important for the coherence tests on carbon balance were it is expected to establish the carbon mass processed in a transformation center or in sectors where consumption (in terms of BEN) is direct

3 – Corrections in the Calculation of Emissions from Renewable and Non- Renewable Sources

One of problems found in previous calculations and in the comparison of results of the Carbon Balance Project with other studies is due to the distinction between renewable and non-renewable energy sources. The emitted carbon by renewable sources (fuel) is not incorporated in the atmospheric carbon inventory because it is entirely recycled by biosynthesis if production is in permanent regime. However, when the carbon balance is used as a control instrument regarding adequate emission coefficients, all carbon involved in energy use and transformation should be considered and this demands the separation of the National Energy Balance into the two categories (renewable and non-renewable).

The emission coefficients used are also different: it was used the in the case of Other Recoveries the 20.0 tC/TJ factor for the non-renewable sources (as petroleum) and in the case of renewable ones it was used the value of vegetal residues, that is, 29.9 tC/TJ.

For most energy sources there is no doubt regarding their origin (renewable or not) both for primary and secondary sources. This is not true for the mentioned item [3], that in most cases is considered as a share of the renewable sources, including in studies carried out by e&e (ref. Carbon Balance Final  Report of December 2005). In the case of transformation one can also identify the type of energy source by the products that are generated or by the type of transformation (e.g. refineries transform non-renewable sources).

According to information from those responsible for the Energy Balance at MME one should consider that one part of this item is renewable and the other is non-renewable. The “toe” spreadsheet for “accounts” and energy sources from the BEN data was then used, and the different accounts that participate in this energy source were analyzed in order to separate the renewable part. These values and two options for the energy sources were included in the   bal_eec program. To feed these values in the energy spreadsheet it was used the Other Non Renewable column available at the extended Balance structure (BEN 49X46) but whose content is zero for all years. The renewable sources were maintained in the original column.

The staff responsible for the Energy Balance is working in order to supply definite numbers regarding the share of renewable and non-renewable sources in this item for several years. The approximation adopted here (based on the distribution of the existing years) gives a preliminary estimate.

The following criteria were adopted for separating Other Recoveries into renewable and non-renewable sources:

·         Refineries and Natural Gas Producing Units (non-renewable);

·         Public Service Power Plants: the source is renewable (wind power) and there is no direct emission (emission coefficient equal to zero);

·         Autoproducers Power Plants: classification into  renewable and non-renewable sources according to Table 3.1, and for the previous and subsequent years average values were considered. It should be noted the presence of sulfur where there is no emission involved (excluded in the emission calculation). However, sulfur was  kept in the energy balance in the non-renewable part so that the energy balance calculation remains coherent with BEN’s data;

·         Industrial Sector: Cement Industry (considered half renewable and half non- renewable), Chemical Industry (considered as non-renewable), Paper and Cellulose Industry (considered as renewable) and Ceramics Industry (considered as renewable);

·         Gases from Blast Furnaces and Steelworks are non-renewable.


 

Table 3.1: Distribution of Fuels in the Autoproducers Power Plants Included  in the “Other Renewable” item of BEN

AUTOPRODUCERS POWER PLANTS

ENERGY CONSUMPTION IN  ELECTRICITY GENERATION

OTHER  RENEWABLE thou toe

1992

1993

1994

1995

1996

1997

1998

1999

FOREST RESIDUES

45

77

46

34

35

50

59

77

BLAST FURNACES (+) STEELWORKS GAS

378

398

292

293

284

370

371

364

SULFUR FUSION

 

 

 

 

 

 

 

73

TOTAL

423

475

338

327

319

420

430

513

 

 

 

 

 

 

 

 

 

OTHER RENEWABLE
(continuation) thou  toe

2000

2001

2002

2003

2004

2005

2000

 

FOREST RESIDUES

80

119

126

110

120

213

80

 

BLAST FURNACES (+) STEELWORKS GAS

685

763

803

817

787

826

685

 

SULFUR FUSION

74

87

83

91

106

102

74

 

TOTAL

839

969

1012

1018

1013

1141

839

 

Source: MME/BEN

In Table 3.2 it is shown the distribution of energy sources in “Other Renewable” regarding renewable and non-renewable sources.

Table 3.2: Distribution of renewable and non-renewable sources in the Other Recoveries Item for the year 2000

    Account

  OTHER  NON
RENNEWABLE

 OTHER RECOV..
 RENEWABLE

Observations

PETROLEUM REFINERIES

-689,77

0,00

100% non-renewable

NATURAL GAS PLANTS

605,80

0,00

100% non-renewable

PUBLIC SERVICE POWER PLANTS

0,00

0,00

Wind Energy

AUTOPRODUCERS POWER PLANTS

-759,00

-80,00

Vegetation Residues (-80),
Sulfur (-74),
Blast Furnace + Steelworks (-685)

OTHER TRANSFORMATIONS

84,00

0,00

100% non-renewable

CEMENT  

54,48

54,48

50% renewable 50% non renewable

CHEMISTRY

154,00

0,00

100% non-renewable

PAPER AND CELLULOSE             

0,00

405,86

100% renewable

CERÂMICS

0,00

39,99

100% renewable

 

4 – Treatment of Transformation Centers

In the previous evaluation carried out for MCT significant differences in the  carbon balance were found and in some cases differences in energy in Transformation Centers. BEN presents the following transformation centers:

  •          Petroleum Refineries *

  •          Natural Gás Plants*

  •          Gasification Plants*

  •          Coking Plants*

  •          Distilleries*

  •          Charcoal Plants

  •          Public Service Power Plants

  •          Autoproducers Power Plants

  •          Nuclear Fuel Cycle

  •          Other Transformations

Transformation centres can be divided into two groups according to the treatment they get in BEN. In those with (*) the energy consumption is not considered in the transformation centers themselves but rather as energy consumption in the so called “energy sector”. So the energy used in refining is accounted for in the energy sector as consumption of products (refinery gas, fuel oil, etc.). In the case of distilleries, energy consumption from bagasse is also accounted for in the energy sector.

Emission calculations for the inventory adopted an analogous procedure. For this reason it includes only emissions associated with electricity power plants and charcoal plants. In the case of carbon balance it must be balanced in all cases when emitted gases are included. This study will precisely test the consistency between the amount of carbon that constitutes the “input” and the “output” made up by the emitted carbon-containing gases, by the retained or non-oxidized carbon and, as in the case of transformation, by the products (or wastes) that are generated.

In what follows it will be presented the results of the Energy (only graphics) and Carbon(graphics and tables) Balances for the following Transformation Centers: Petroleum Refineries, Natural Gas Plants, Gasification Plants, Coking Plants, Distilleries and Charcoal Plants. Corrections that were considered pertinent were implemented and will be considered in the results. Except for charcoal plants, it is expected that the energy and carbon balances (input x output) are right for each type of center.

Calculation is based on the values (Output – Input) that  in BEN’s structure that was adopted by the program corresponds to the Total item in the line of each Transformation Center. So an ad-hoc table is built for the account pertaining to the focused Transformation Center. The program is run for all years (from 1970 to 2005) both for energy (toe) and Carbon Mass (Gg of C). The Energy and Carbon Balances Graphics are built using the difference percent values (Total/Input).

4.1 Carbon Balance in Petroleum Refineries

In the case of Petroleum Refineries the ad-hoc tables are built for the Petroleum Refinery account, with the columns Primary Energy (Petroleum plus Other Non Renewable) – that correspond to Input - and Total (Input -Output). The carbon mass values in Gg (thousand  tons) can be seen in Table 4.1.

With the percent difference values (Total/Input) is built the Energy and Carbon Balance Graphics in Petroleum Refineries (Figure 4.1) that is shown with the corresponding energy value.

TABLE 4.1:Values of Contained Carbon in Gg of Carbon for Petroleum Refineries

Petroleum Refineries      Carbon Mass in Gg

YEAR

PRIMARY ENERGY

TOTAL

PERCENT DIFFERENCE

1970

-21376

-559

-2,62%

1971

-22675

-196

-0,87%

1972

-27049

-339

-1,25%

1973

-32300

-449

-1,39%

1974

-34550

-409

-1,19%

1975

-37527

-398

-1,06%

1976

-39777

-355

-0,89%

1977

-40861

-426

-1,04%

1978

-45555

-432

-0,95%

1979

-47407

-97

-0,21%

1980

-46335

-459

-0,99%

1981

-44971

109

0,24%

1982

-44593

165

0,37%

1983

-43422

-201

-0,46%

1984

-46275

-399

-0,86%

1985

-46664

-131

-0,28%

1986

-49715

-50

-0,10%

1987

-50896

-36

-0,07%

1988

-51158

-682

-1,33%

1989

-51439

-410

-0,80%

1990

-50820

-35

-0,07%

1991

-49280

-523

-1,06%

1992

-51317

-779

-1,52%

1993

-51840

-1017

-1,96%

1994

-54784

-737

-1,35%

1995

-53475

-403

-0,75%

1996

-57288

-546

-0,95%

1997

-61576

-218

-0,35%

1998

-66297

-678

-1,02%

1999

-68535

-711

-1,04%

2000

-69345

-369

-0,53%

2001

-71783

-498

-0,69%

2002

-70318

-760

-1,08%

2003

-70258

-139

-0,20%

2004

-74095

-15

-0,02%

2005

-74278

-37

-0,05%

 

Figure 4.1: Energy and Carbon Balance in Petroleum Refineries

Energy and Carbon Balances show a similar behavior along the years and a small mass deviation. It seems that an appropriate emission coefficient choice was made and that the different characteristics of the fuel had small influence on carbon balance in petroleum refineries along the years. The fact that carbon balance is negative is compatible with transformation losses that are not recorded in BEN.

4.2 Carbon Balance in Natural Gas Plants

For the Natural Gas Processing Units (NGPU) liquids are extracted from humid natural gas that condensate at room temperature and it remains dry natural gas composed mainly of methane and ethane. The liquid fractions can be directly incorporated to some products (LPG, Naphtha, etc.) or receive treatment in Natural Gas plants. This seems to be the preferential destination in recent years perhaps because it facilitates the homogeneous characteristics of commercialized products and simplifies the operation of the NGPUs.  

In Table 4.2 are shown the results of the ad-hoc tables built for the Natural Gas Plants account and the Humid Gas (Input) and Total (Output– Input) columns for carbon mass values.

TABLE 4.2: Contained Carbon Values in Gg of Carbon for Natural Gas Plants

Natural Gas Plants     Carbon Mass in Gg

YEAR

HUMID GAS

TOTAL

PERCENT DIFFERENCE

1970

-380

-2

-0,48%

1971

-612

-10

-1,68%

1972

-676

-16

-2,38%

1973

-663

-18

-2,74%

1974

-790

-21

-2,64%

1975

-835

-14

-1,72%

1976

-869

-20

-2,32%

1977

-1002

-32

-3,22%

1978

-999

-29

-2,95%

1979

-892

-16

-1,77%

1980

-894

-14

-1,59%

1981

-1067

-15

-1,40%

1982

-1195

-17

-1,40%

1983

-1392

-11

-0,78%

1984

-1812

-25

-1,40%

1985

-2108

-80

-3,78%

1986

-2436

-9

-0,37%

1987

-2895

5

0,18%

1988

-2721

-59

-2,15%

1989

-2784

-102

-3,65%

1990

-2825

-75

-2,64%

1991

-3148

-120

-3,81%

1992

-3419

-19

-0,57%

1993

-3211

-59

-1,85%

1994

-3352

-24

-0,72%

1995

-3372

-9

-0,25%

1996

-3541

-50

-1,42%

1997

-3722

-4

-0,09%

1998

-4028

-16

-0,39%

1999

-4430

-51

-1,15%

2000

-5587

-288

-5,15%

2001

-5879

-247

-4,20%

2002

-6738

-201

-2,98%

2003

-7407

-49

-0,66%

2004

-7732

-130

-1,68%

2005

-9209

-281

-3,05%

Using the percent differences regarding carbon mass (in Gg) and energy (in toe) it was built the Energy and Carbon Balance in Natural Gas Plants (Figure 4.2).

FIGURE 4.2: Energy and Carbon Balance in Natural Gas Plants

It can be noticed in Figure 4.2 that from 1995 on there is practically no difference between the energy and carbon balances in spite of the fact that the same emission factor was used for all the years. In the years before 1995 the curves follow exactly the same trend but with a systematic component of the variation. This can be explained by the use of coefficients that are not adequate if natural gas from different origins have been used during this period.

The different composition of the liquid products obtained indicates that the humid gas treated in the NGPU had varied compositions as shown in Figure 4.3. The largest percent value of liquids obtained in the first years indicates a more “humid” natural gas (containing a larger liquid fraction) or a smaller liquid extraction in the last years. In this case the conversion coefficient from natural units (m3) to toe should be different for each year. In the same way different coefficients should be used for carbon mass calculation (tC/toe).[4]

It can also been seen in Figure 4.2 that there is a trend both for energy and carbon to be negative and not distributed around zero. Systematic negative values indicate losses since systematic positive values certainly involve errors regarding the mass/and or energy coefficients used.

Figure 4.3: Percent value of carbon mass obtained from humid natural gas has varied substantially from 1988 on, what justifies the deviation of carbon balance relative to energy balance observed in the previous figure .

When the Carbon Balance is calculated according to what is shown in Phase 1 (Ref. 2) each ten years until 2005, one has the values of Table 4.3. In this table it can be observed that in most years the Carbon Balance does not present deviations above the expected value and whenever this occurs the variation could be due to variation ob carbon content in the humid gas that is not reflected in the coefficients used (considered as constant).

TABELE 4.3: Carbon Balance in selected years (mass in Gg) for Natural Gas Plants

 

1970

1980

1990

2000

2005

INPUT (HUMID NAT. GAS)

-380

-894

-2825

-5587

-9209

OUTPUT

378

879

2750

5299

8812

DRY NAT. GAS

304

718

2219

4213

7188

OTHER REC.NON RENEW.

0

0

0

507

576

GASOLINE

28

60

134

184

161

LPG

46

101

394

269

786

NAPHTHA

0

0

3.2

126

101

BALANCE

-2

-14

-75

-287

-393

BALANCE(%)

0,65%

1,72%

2,63%

5,16%

4,31%

 

4.3 Carbon Balance in Coking Plants

In Coking Plants, metallurgical coal is converted in mineral coal coke (used in steel fabrication) in a distillation process in the absence of oxygen. Gases and liquids are produced as side products and the gases are used as fuel in steelworks including the coking itself, as well as liquids.

The gases are recorded in the Balance as coking gas and the liquids as tar. Calculations were carried out with two different emission factors for coking gas and concerning tar, since we have no value suggested by IPCC, the value used in the Initial Inventory was adopted, namely 25.8 tC/TJ.

The carbon balance is shown in Table 4.4 and it is compared, in Figure 4.4, with the energy balance. In the case of Coking Plants the input is Metallurgical Coal (National and Imported) and the output is mineral coal coke, coke oven gas and tar.

TABLE 4.4: Values of Contained Carbon in Gg of Carbon for Coking Plants  

Coking Plants    Carbon Mass in Gg

ANO

METALLURGICAL COAL

MIN. COAL COKE

COKE OVEN GAS

OTHER SEC. AND TAR

TOTAL

PERCENT DIFFERENCE

1970

-1714

1375

390

65

114

6,67%

1971

-1777

1430

388

70

111

6,26%

1972

-1808

1439

396

74

101

5,61%

1973

-1943

1548

435

79

119

6,14%

1974

-1948

1535

418

76

80

4,13%

1975

-2399

1915

517

94

128

5,33%

1976

-3071

2450

668

109

156

5,08%

1977

-3644

2919

768

122

165

4,52%

1978

-3678

3045

799

145

311

8,45%

1979

-4215

3447

886

158

277

6,57%

1980

-4383

3632

921

192

362

8,26%

1981

-3950

3464

841

175

530

13,43%

1982

-4114

3424

910

194

413

10,05%

1983

-4885

4015

1078

236

445

9,11%

1984

-6555

5414

1422

297

578

8,82%

1985

-7419

6145

1586

293

606

8,17%

1986

-7588

6234

1619

314

579

7,63%

1987

-7908

6488

1838

303

721

9,12%

1988

-8329

6910

1976

321

879

10,55%

1989

-8273

6848

1991

315

880

10,64%

1990

-8143

6502

1688

291

338

4,15%

1991

-8361

6886

1801

330

656

7,85%

1992

-8628

6949

1823

317

461

5,34%

1993

-8939

7241

1900

329

531

5,94%

1994

-8692

7039

1864

317

528

6,08%

1995

-8763

7095

1881

299

513

5,85%

1996

-8754

7117

1910

286

560

6,39%

1997

-8427

6946

1834

310

662

7,86%

1998

-8169

6737

1800

293

661

8,10%

1999

-7492

6209

1667

270

655

8,74%

2000

-7875

6543

1764

270

702

8,91%

2001

-7658

6490

1735

255

822

10,73%

2002

-7431

6329

1687

247

832

11,20%

2003

-7369

6139

1736

251

757

10,28%

2004

-7920

6662

1842

259

844

10,65%

2005

-7746

6621

1812

238

926

10,65%

 

FIGURE 4.4: Energy and Carbon Balance in Coking Plants showing the values calculated with the 29,5 and 13,0 tC/TJ (correction) coefficients for coking plant gas; the corrected  carbon balance values practically coincide with those of the energy balance.

A similar behavior is found in the Carbon and Energy Balances but the two curves are too distant from each other showing a systematic error due to the use of an emission factor that is not adequate for calculating carbon emission. As there was no factor calculated by e&e for coke oven gas, the value adopted by the Inventory (29,5 tC/TJ) was initially used.

IPCC suggest for coke plant gas (in the case of sectorial calculations, as the case here) the13.0 tC/TJ value. This low value (relative to the other energy sources) is justified by the hydrogen that is present in this type of gas. The calculations were then repeated using  this value and the corrected curve is presented in Figure 4.4.

It should be noticed that in Figure 4.4 the curves follow the same behavior and there still a systematic error (even though much smaller than the previous one) that can be assigned to the energy balance as the behavior of both curves is practically the same.

4.4 Carbon Balance in Gasification Plants

Piped gas for distribution to the network existing in 1970, practically restricted to the cities of Rio de Janeiro and São Paulo, was produced in gasification plants. Between 1970 and 2002 the raw material used in its fabrication changed from the predominant mineral coal (most of it metallurgical) to naphtha (petroleum product) and finally, to natural gas. The availability of natural gas for distribution caused the change of the old network and of consumer’s equipment so that in the last years there was only a residual production in these plants that were deactivated from 2003 on.

In Table 4.5 are shown the data from the bal_eec program and in Figure 4.5 the Energy and Carbon Balances for Gasification Plants

FIGURE 4.5: Energy and Carbon Balances in Gasification Plants

TABLE 4.5: Values of  Contained Carbon in Gg of Carbon for Gasification Plants

Gasification Plants       Carbon Mass in Gg

YEAR

DRY NATU RAL GAS

METALLURGICAL COAL

  NAPHTHA      

TOTAL

PERCENT

DIFFERENCE

1970

0

-184

-65

-66

-26,41%

1971

0

-158

-84

-68

-27,95%

1972

0

-106

-132

-83

-34,90%

1973

0

-43

-163

-84

-40,40%

1974

0

-3

-182

-43

-23,05%

1975

0

0

-205

-49

-23,98%

1976

0

0

-203

-39

-19,03%

1977

0

0

-200

-25

-12,54%

1978

0

0

-217

-31

-14,45%

1979

0

0

-226

-34

-14,81%

1980

0

0

-226

-32

-13,99%

1981

0

0

-249

-44

-17,78%

1982

0

0

-254

-39

-15,25%

1983

-54

0

-176

-3

-1,29%

1984

-103

0

-136

-6

-2,63%

1985

-96

0

-157

-23

-9,09%

1986

-103

0

-150

-1

-0,21%

1987

-111

0

-155

-7

-2,45%

1988

-99

0

-168

-4

-1,64%

1989

-118

0

-142

-1

-0,53%

1990

-109

0

-137

-16

-6,62%

1991

-91

0

-128

6

2,53%

1992

-107

0

-96

0

0,18%

1993

-90

0

-100

1

0,33%

1994

-87

0

-67

-27

-17,61%

1995

-86

0

-57

-31

-21,82%

1996

-57

0

-43

6

5,49%

1997

-54

0

-43

-5

-5,32%

1998

-87

0

0

8

9,69%

1999

-75

0

0

5

6,98%

2000

-47

0

0

25

52,27%

2001

-84

0

0

-54

-64,39%

2002

-23

0

0

1

4,65%

2003

0

0

0

0

 

2004

0

0

0

0

 

2005

0

0

0

0

 

 When Dry Natural Gas was used together with Naphtha, both curves practically coincide from 1983 to 1994, but subsequently and until 2002 there are large variations even after adjustments of the emission coefficient regarding dry natural gas.  These variations are present in both curves and reach 70% which shows that there is some problem concerning energy source data or its interpretation. The low relative importance of these plants in energy consumption and emissions do not justify a great effort to clarify the differences found.

4.5 –Carbon Balance in Alcohol Distilleries

The emission coefficient previously used for alcohol was 14.8 tC/TJ. According to calculations carried out by e&e and that are part of Report 1 as Technical Note 2 published in the N° 57 issue of this periodical, this coefficient was changed to 18.8 tC/TJ for both Anhydrous and Hydrated Alcohol.

As input to Distilleries we have Sugarcane Liquor and Molasses and as output Anhydrous and Hydrated Alcohol. The results obtained by the bal_eec program for the contained carbon balance are presented in Table 4.6.

In the Carbon Balance analysis in a alcohol distillery the wastes are combustion gases represented by CO2 , fermentation gas (CO2) and glycerol considered as a representative of carbon compounds rejected as vinhoto. Therefore, a correction was introduced using data regarding carbon content in biomass from Technical Note 2 of Report 1 (see e&e N° 57). The results of this correction are presented in Table 4.7.

TABLE 4.6: Values of Contained Carbon in Gg for Distilleries

Destilleries       Carbon Mass in Gg

YEAR

SUGARCANE LIQUOR

MOLASSES

ANHYDROUS    ALCOHOL 

HYDRATED ALCOHOL

TOTAL

PERCENT DIFFERENCE

1970

-68

-235

98

157

-49

-16,02%

1971

-68

-235

166

92

-45

-14,98%

1972

-75

-257

168

114

-50

-15,17%

1973

-71

-246

134

133

-49

-15,52%

1974

-67

-232

90

160

-48

-16,12%

1975

-63

-218

92

144

-45

-15,98%

1976

-70

-242

114

148

-49

-15,78%

1977

-254

-434

457

120

-111

-16,16%

1978

-764

-391

777

160

-227

-19,65%

1979

-1118

-365

978

211

-311

-20,99%

1980

-1498

-410

914

602

-422

-22,10%

1981

-1682

-503

566

1147

-511

-23,37%

1982

-2283

-675

1482

839

-672

-22,70%

1983

-3446

-780

1074

2164

-1022

-24,18%

1984

-4143

-627

900

2831

-1093

-22,92%

1985

-5166

-695

1321

3376

-1230

-20,99%

1986

-4504

-553

891

3153

-1053

-20,82%

1987

-5504

-719

905

4085

-1241

-19,95%

1988

-5039

-675

708

3945

-1068

-18,68%

1989

-4972

-637

628

4137

-909

-16,20%

1990

-5009

-675

357

4279

-1099

-19,33%

1991

-5657

-684

859

4339

-1200

-18,93%

1992

-4988

-758

935

3826

-1035

-18,01%

1993

-4721

-707

1061

3557

-854

-15,73%

1994

-4970

-884

1176

3896

-829

-14,16%

1995

-4795

-988

1262

3907

-652

-11,28%

1996

-5303

-1161

1862

3891

-751

-11,62%

1997

-5939

-1155

2383

3939

-772

-10,88%

1998

-5117

-1295

2388

3384

-569

-8,87%

1999

-4464

-1409

2594

2730

-548

-9,34%

2000

-3728

-1109

2371

2028

-438

-9,06%

2001

-3785

-1394

2723

1999

-457

-8,82%

2002

-4016

-1594

2958

2225

-427

-7,61%

2003

-4651

-1736

3711

2263

-413

-6,47%

2004

-4661

-1775

3302

2724

-409

-6,35%

2005

-5109

-1939

3449

3143

-456

-6,47%

 

TABLE 4.7: Values of Carbon in Gg in Distilleries corrected for vinhoto and CO2  from Fermentation

Corrections for Gas from Fermentation and Vinhoto  Carbon Mass in Gg

YEAR

SUGARCANE LIQUOR

MOLASSES

ANHYDROUS ALCOHOL 

HYDRATED ALCOHOL

TOTAL

CORRECTED TOTAL

DIFERENÇA CORRIGIDA

1970

-68

-235

98

157

-49

-31

-10,06%

1971

-68

-235

166

92

-45

-27

-8,95%

1972

-75

-257

168

114

-50

-30

-9,15%

1973

-71

-246

134

133

-49

-30

-9,52%

1974

-67

-232

90

160

-48

-30

-10,16%

1975

-63

-218

92

144

-45

-28

-10,02%

1976

-70

-242

114

148

-49

-31

-9,80%

1977

-254

-434

457

120

-111

-70

-10,21%

1978

-764

-391

777

160

-227

-161

-13,90%

1979

-1118

-365

978

211

-311

-227

-15,30%

1980

-1498

-410

914

602

-422

-314

-16,47%

1981

-1682

-503

566

1147

-511

-389

-17,80%

1982

-2283

-675

1482

839

-672

-507

-17,14%

1983

-3446

-780

1074

2164

-1022

-792

-18,75%

1984

-4143

-627

900

2831

-1093

-829

-17,37%

1985

-5166

-695

1321

3376

-1230

-897

-15,30%

1986

-4504

-553

891

3153

-1053

-766

-15,14%

1987

-5504

-719

905

4085

-1241

-887

-14,26%

1988

-5039

-675

708

3945

-1068

-737

-12,90%

1989

-4972

-637

628

4137

-909

-570

-10,17%

1990

-5009

-675

357

4279

-1099

-770

-13,54%

1991

-5657

-684

859

4339

-1200

-831

-13,11%

1992

-4988

-758

935

3826

-1035

-697

-12,13%

1993

-4721

-707

1061

3557

-854

-526

-9,69%

1994

-4970

-884

1176

3896

-829

-469

-8,02%

1995

-4795

-988

1262

3907

-652

-285

-4,94%

1996

-5303

-1161

1862

3891

-751

-343

-5,31%

1997

-5939

-1155

2383

3939

-772

-323

-4,55%

1998

-5117

-1295

2388

3384

-688

-278

-4,34%

1999

-4464

-1409

2594

2730

-548

-171

-2,90%

2000

-3728

-1109

2371

2028

-486

-174

-3,59%

2001

-3785

-1394

2723

1999

-504

-169

-3,26%

2002

-4016

-1594

2958

2225

-474

-107

-1,90%

2003

-4651

-1736

3711

2263

-413

11

0,17%

2004

-4661

-1775

3302

2724

-409

19

0,30%

2005

-5109

-1939

3449

3143

-456

8

0,12%

Figure 4.6 presents Energy and Carbon Balance in Distilleries, as well as the correction regarding fermentation gas and vinhoto.

FIGURE 4.6: Energy and Carbon Balances in Distilleries

Even though the energy curves behavior (difference in tep) in Figure 4.6 are “parallel” they have a gap even when the new carbon emission factor calculated for alcohol was used.

As can be observed in the same curve, the corrections introduced for vinhoto and CO2 from fermentation made the Energy and Carbon Balances practically coincident.

The results of energy and carbon balances is satisfactory only in the last years; for the first ones there are important differences. Anyway, the calculation of the quantities of processed sugarcane liquor and molasses is probably problematic. It should be taken into account that the normal procedure in these cases is to deduce the quantity of raw material from the product. A change in the factor that correlates raw material and product can be responsible for improving the balance.

4.5 –Carbon Balance in Charcoal Plants

In the case of charcoal plants, the primary energy, firewood, is transformed into charcoal by partial burning. The sub-products of charcoal production are insoluble tar and pyroligneous liquid. The proportions of the pyrolisis products varies according to the firewood quality and the combustion temperature.  

In Table 4.8 are presented the carbon balance of charcoal plants without corrections.

Corrections in the analysis of carbon balance in charcoal plants should be introduced to take into account the liquid and gaseous effluents resulting from combustion. Therefore a correction was introduced using data from Technical Note 2 of Report 1 (e&e N° 57). The results of this correction are presented in Table 4.8.

 Figure 4.7 presents the Energy and Carbon Balances in Chracoal Plants as well as the corrections regarding tar and pyroligneous liquid and the inclusion of CO and CO2.

Figure 4.7 Energy and carbon balances in charcoal plants with corrections (for carbon mass) concerning wastes and emissions.

TABLE 4.8: Values of Carbon in Gg for Charcoal Plants

Charcoal Plants      Carbon Mass in Gg

YEAR

  FIREWOOD

CHARCOAL

TOTAL

PERCENT DIFFERENCE

1970

-4182

2211

-1971

-47,13%

1971

-4763

2518

-2245

-47,13%

1972

-5520

2918

-2602

-47,13%

1973

-5858

3097

-2761

-47,14%

1974

-7305

3862

-3443

-47,13%

1975

-8734

4618

-4117

-47,13%

1976

-7924

4189

-3735

-47,13%

1977

-8056

4259

-3797

-47,14%

1978

-8246

4359

-3887

-47,14%

1979

-9708

5132

-4576

-47,13%

1980

-10991

5810

-5180

-47,13%

1981

-10439

5519

-4920

-47,13%

1982

-10578

5592

-4986

-47,13%

1983

-11896

6289

-5607

-47,13%

1984

-14704

7780

-6924

-47,09%

1985

-15401

8142

-7259

-47,13%

1986

-16255

8594

-7662

-47,13%

1987

-15815

8361

-7454

-47,13%

1988

-16842

8904

-7939

-47,13%

1989

-18738

9914

-8824

-47,09%

1990

-15298

8094

-7204

-47,09%

1991

-13416

7099

-6318

-47,09%

1992

-12317

6518

-5799

-47,08%

1993

-12965

6860

-6105

-47,09%

1994

-13125

6944

-6181

-47,09%

1995

-12081

6391

-5689

-47,09%

1996

-10709

5893

-4816

-44,97%

1997

-10300

5667

-4633

-44,98%

1998

-9380

5161

-4218

-44,97%

1999

-10164

5700

-4463

-43,91%

2000

-11114

6233

-4881

-43,92%

2001

-10325

5682

-4644

-44,97%

2002

-10800

5942

-4857

-44,97%

2003

-12720

6999

-5721

-44,97%

2004

-14733

8153

-6579

-44,66%

2005

-14571

7998

-6573

-45,11%

TABLE 4.9: Values of Carbon in Gg for Charcoal Plants with correction regarding Tar and Pyroligneous Liquids, CO and CO2

Corrections for Tar+ Pyroligneous Liquids, CO and CO2 in Chracoal Plants Gg of Carbon

YEAR

FIREWOOD

CHARCOAL

PYROLIGNEOUS AND TAR

CO and CO2 EMISSIONS

CORRECTED TOTAL

CORRECTED DIFFERENCE

1970

-4182

2211

1290

369

-313

-7,48%

1971

-4763

2518

1469

420

-357

-7,48%

1972

-5520

2918

1702

486

-413

-7,49%

1973

-5858

3097

1806

516

-439

-7,49%

1974

-7305

3862

2253

644

-547

-7,48%

1975

-8734

4618

2694

770

-654

-7,48%

1976

-7924

4189

2444

698

-593

-7,48%

1977

-8056

4259

2484

710

-603

-7,49%

1978

-8246

4359

2543

727

-617

-7,49%

1979

-9708

5132

2994

855

-727

-7,48%

1980

-10991

5810

3389

968

-823

-7,49%

1981

-10439

5519

3219

920

-781

-7,48%

1982

-10578

5592

3262

932

-792

-7,48%

1983

-11896

6289

3668

1048

-891

-7,49%

1984

-14704

7780

4538

1297

-1089

-7,41%

1985

-15401

8142

4749

1357

-1152

-7,48%

1986

-16255

8594

5013

1432

-1216

-7,48%

1987

-15815

8361

4877

1393

-1184

-7,49%

1988

-16842

8904

5194

1484

-1261

-7,48%

1989

-18738

9914

5783

1652

-1388

-7,41%

1990

-15298

8094

4722

1349

-1133

-7,41%

1991

-13416

7099

4141

1183

-994

-7,41%

1992

-12317

6518

3802

1086

-910

-7,39%

1993

-12965

6860

4002

1143

-960

-7,41%

1994

-13125

6944

4051

1157

-973

-7,41%

1995

-12081

6391

3728

1065

-896

-7,41%

1996

-10709

5893

3437

982

-397

-3,70%

1997

-10300

5667

3306

945

-382

-3,71%

1998

-9380

5161

3011

860

-347

-3,70%

1999

-10164

5700

3325

950

-188

-1,85%

2000

-11114

6233

3636

1039

-206

-1,85%

2001

-10325

5682

3314

947

-382

-3,70%

2002

-10800

5942

3466

990

-400

-3,71%

2003

-12720

6999

4083

1167

-471

-3,71%

2004

-14733

8153

4756

1359

-464

-3,15%

2005

-14571

7998

4665

1333

-575

-3,95%

 

The energy contained in firewood is not completely transformed into charcoal because part of it is contained in the waste and sub-products. Therefore, a correction could be introduced that would take into account the energy contained in tar and pyroligneous liquid produced. This was not made because the energy contents of these substances are not available. It should be remembered that in this case a balance is not maintained as in the previous cases because this is not a transformation center where the consumed energy is accounted for in the so called energy sector.

5. Conclusion

The problems examined in the present report are those regarding issues resulting from carbon balance and emissions analysis. In the biomass fuels the analysis had already indicated the correction of important emission factors such as the one referring to carbon content in alcohol. 

Separation of renewable and non-renewable components in the Other Recoveries item has permitted the listing of those that must be considered in the greenhouse effect accounting. The importance of these corrections is more methodological than quantitative.

Regarding the transformation centers, important quantitative corrections were made, mainly in centers where biomass is the primary energy. Corrections to be made in the energy balance itself were also indicated. The calculation of carbon balance permitted the identification of inadequate choices of emission coefficients (the case of coke oven gas), omission of emissions during alcohol processing (carbonic gas from fermentation) and inadequate energy coefficients (humid natural gas) and identifying sub-products that were not accounted for (tar and pyroligneous liquids in charcoal plants).

In the preset report the carbon balance methodology was improved through the more precise determination of carbon content of the derived products. These values are used in the carbon balance to check the results of emissions calculated with the Bottom-Up and Extended Top-Down Processes.

References

1 – MCT 2006 - Emissões de Dióxido de Carbono por Queima de Combustíveis: Abordagem Top-Down – Primeiro Inventário Brasileiro de Emissões Antrópicas de Gases de Efeito Estufa, Relatório de Referência.

2 – Relatório Final, Projeto: Balanço de Carbono – Convênio MCT – Economia e Energia No 010065.00/2003.

3 – MME, 2005 Balanço Energético Nacional.

4 – IPCC, 1996. Greenhouse Gas Inventory Reporting Instructions – Revised IPCC Guidelines for National Greenhouse Gas Inventory, Vol. 1,2,3 – IPCC,IEA, OECD.

5 – Relatório 1, Consolidação do Balanço de Carbono, Termo de Parceria entre o MCT e a OSCIP Economia e Energia e&e.


[1] Programs used by e&e in previous studies and developed by Ecen Consultoria Ltda.

[2] The application of a generic coefficient on the item does not permit to distinguish the renewable share from the non- renewable one. On the  other hand if one adopts this procedure one would be attributing emission to sulfur and wind energy that, as well known, do not directly contribute to carbon emission to the atmosphere.

[3] There is also a problem concerning methanol accounting that in BEN/MME is incorporated in ethanol. In this case it was not possible during the study to find an adequate source of data to treat methanol separately.

[4] In the present study the basic values of BEN were not changed because we consider that any change should be carried out by those responsible for the Balance. For petroleum products and petroleum itself  BEN indicates different annual values regarding energy content; the same could be considered for the case of humid natural gas.

 

Graphic Edition/Edição Gráfica:
MAK
Editoração Eletrônic
a

Revised/Revisado:
Thursday, 05 May 2011
.

Contador de visitas