Economy & Energy
Year IX -No 62:
June -
July 2007 
ISSN 1518-2932

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Presentation of the Preliminary Version of Carbon Balance for Discussion

Carbon Balance

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Carbon Balance

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Annexes  1970- 2005

 

 

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Text for Discussion :

Carbon Balance

 

Summary

1.Introduction.

2. Methodology.

2.1 Carbon Balance.

2.2 Emissions by the Top-Down Extended Methodology.

2.3 Greenhouse Effect Emissions in the Bottom-Up by Coefficients Methodology.

2.4 Biomass Treatment

3. Carbon Emission.

3.1 Data Aggregation and Chosen Years.

3.2 Emissions Calculation.

3.3 Sectorial Carbon Emissions.

3.4 Carbon Emissions by Fuel Type.

3.5 Summary of Carbon Emissions.

4. CO2 Emissions.

4.1 Carbonic Gas Accounting.

4.2 Comparison with the Inventory Values.

4.3 Form of CO2 Balance Presentation.

4.4 Evolution of CO2 Emissions by Fuel

4.5 Evolution of CO2 Emissions by Sector (Account)

4.6 Summary of CO2 Emissions.

5. CH4 Emissions.

6. CO Emissions.

7. NMVOCs Emissions.

8. Results and Methodological Apendix.

9 Using the bal_eec Program to Obtain Results.

10 Acronyms and Symbols Used

 1.Introduction

Brazil participates in the United Nations Framework Convention on Climate Change and had committed itself to carry out periodically a survey of the anthropic emissions of greenhouse effect gases.

The Ministry of Science and Technology – MCT, is responsible for the coordination of this study that includes several governmental and private organs.

An important part of emissions from human activities is related to energy production, transformation and use. In order to evaluate these emissions it is necessary to use the data from the National Energy Balance – BEN, edited by the Ministry of Mines and Energy for more than thirty years and now under the responsibility of the Energy Research Enterprise – EPE.  

The Energy Balance is based on an important characteristic of energy, namely its conservation, established by the First Law of Thermodynamics. It permits to make a balance considering energy in its primary forms (petroleum, wood, hydro energy, natural gas, mineral coal, etc.) and its transformation that converts it to secondary forms easier to use (gasoline, charcoal, electricity, coke, etc.) that are finally used in the different sectors of human activities (residences, industries, vehicles, etc.)

Most of the greenhouse effect emissions are related to gases that contain carbon (mainly carbon dioxide and methane). The so-called fossil energy sources (mineral coal, petroleum and natural gas) have their energy stored in carbon molecules taken from the atmosphere by the photosynthesis effect.

The carbon mass in these processes, as it happens with energy, is also conserved and so it is possible to make a Carbon Balance in the energy sources activities and in other types of activity where there is gas emission. In all complex chemical reactions regarding raw material (e.g.: petroleum), its transformation (in refineries) and finally its emission to the atmosphere at the final use as a gas (mainly CO2) and considering a small amount of retention, the carbon mass follows the Lavoisier Principle: it is transformed, it is not created and it does not disappear.

Carbon Balance  in energy activities can be, as it is the case in Energy Balance, an important evaluation and planning instrument regarding emissions associated with energy. Carbon Balance gives a historical photograph (rather a film) along the years of emissions in the energy area in the Brazilian territory that contribute to the greenhouse effect. For each year it gives emissions maps by energy sector and for each type of gas. 

For the first time the Balance presents a historical view of emissions by energy source and by activity of the different gases in the 1970/2005 period. On the other hand it points out the important role of biomass in Brazil where carbonic gas is initially removed from the atmosphere and is emitted later on, most of it in the form of CO2. In the exports of energy sources from biomass, the “negative emissions” will be credited to the Brazilian energy activities. The calculation of the Carbon Balance has also permitted the identification of several errors and omissions regarding the emissions of greenhouse effect gases.

The presentation of emissions in the form of Carbon Balance unifies the Top-Dow approach that measures the quantity of carbon that “enters” the system, and the Bottom-Up approach where, considering the sectors of the human society activities, it is identified the type of emission per energy source using data concerning the performance of the equipment utilized. In the present study the Bottom-Up analysis was carried out using emission/energy coefficients for each sector and energy form calculated by the MCT for the 1990/1999 period. The emission of gases containing carbon (CO2, CH4, CO and NMVOCs[1]) is calculated by extrapolating these coefficients for the previous and subsequent years of the mentioned period. The values should be considered only as indicative ones, since it is assumed a “freezing” of the technologies used.

The inclusion of data from the Useful Energy Balance, also organized by the MME, associated with data relative to the equipment used in each sector and each use per energy source, will permit to produce more reliable data about these emissions that could be included in future calculations.

Calculations are carried out by a software that is easy to use and where more complete data referring to the 1970/2005 period are available.

This study was possible due to the Partnership Contract 13.0020.00/2005 signed by the Economy and Energy – e&e – OSCIP Organization and the Ministry of Science and Technology – MCT.


2. Methodology

The detailed methodology to obtain the data is described in the reports of the Partnership Contract between e&e and MCT relative to Carbon Balance Consolidation. A summary is presented in what follows.

2.1 Carbon Balance

                Schematically the original energy data are converted to carbon mass through the use of carbon mass /energy coefficients for each energy source. These coefficients are given in tC/toe (ton of carbon per ton oil equivalent)[2]. The carbon masses so obtained are accounted for in the same way as the Energy Balance accounting summarized in Figure 1:

 

Figure 1: Scheme of the National Energy Balance used for carbon mass

However, it should be noticed that the so called “losses” in the case of energy balance should be found in thermal energy as in the case of electricity power plants or leakage or escape in the use and transport of energy fuels. In the case of carbon balance most of these losses return to the atmosphere and should be accounted for in the emissions. In the example of the power plants there is no carbon in the generated electricity and all carbon mass of the fuel used should be accounted for in the emissions.

Since the Energy Balance is not concerned in principle with the carbon mass balance, it would be no surprise at all that when the usual coefficients are used (recommended as default values by the Intergovernmental Panel on Climate Change – IPCC, or those specific for Brazil) some differences are found, some of them significant, between the carbon mass of the primary energy and that of the secondary one and the carbon mass accounted for in the different uses. The carbon balance analysis made it possible a series of corrections in the mass/energy coefficients based on studies  that involved mainly biomass and its products.

Once the carbon balance is established, it is possible to evaluate the emissions considering that all carbon has been converted to CO2except for a small fraction of the fuels used (around 1%) that is not oxidized and is supposed not to return to the atmosphere. There is also a fraction that is not used as energy source and is retained and integrated in materials where retention is considered definitive. This methodology is called Top-Down by the IPCC and will be briefly described below.

2.2 Emissions by the Top-Down Extended Methodology

The use of the Top-Down (TD) methodology recommended by the IPCC in its1996 revision permits to estimate CO2 emissions as a function of data concerning only the energy supply in the country and a few data about the form in which it is used. This methodology consists of accounting the primary and secondary fuels that enter the economic system of a country to satisfy its needs generated by human activities (even the non-commercial ones) and how much carbon leaves the system. Once introduced in the national economy in a given year the carbon contained in a fossil fuel is either emitted to the atmosphere or is retained in some way; for example, it is added to the fuel stock, it is transformed into non-energy products or it is partially retained in non-oxidized form in combustion residues. The energy data used are taken from the BEN.  

The Top-Down (TD) methodology calculates the Apparent Consumption of a country per energy source using the formula;

Apparent Consumption = Production + Imports – Exports      
– International Bunkers + Stock Variations

Practically this concept coincides with that of the Total Internal Supply of BEN/MME where:

Total Internal Supply = Production + Imports – Exports (in BEN it includes Bunkers) + Stock Variations - Non Used – Re-injection

The “Non-Used “ and “Re-injection” concepts refer specifically to the accounting of natural gas that normally is treated separately in the TD process. In the Carbon Balance the re-injection of natural gas into the wells was excluded and the non-used energy (gas that escapes to the atmosphere or is burned in flares during extraction) was accounted for in the present version as entirely converted to CO2.

In a simplified way, the Top-Down methodology suggested by the IPCC can be described as follows:

Calculation of the carbon mass of each fuel in a common energy unit – terajoules (TJ);

Calculation of the carbon quantity of each fuel to be used in non energy ends and subtraction of this carbon mass amount (given by a coefficient for each non energy use) in order to determine the real quantity of emitted carbon;

For fuels to be used for energy purposes, the amount of fuel that is non-oxidized in the combustion will be subtracted using oxidizing factor ;

The oxidized carbon quantity is converted to CO2 emissions by multiplying the carbon mass by 44/12[3].

In the methodology used here emissions are considered at the consumption level instead of in the total energy supply one. In the case of petroleum, for example, the emissions in the TD process would be calculated as the carbon contained in petroleum minus 1% of retention (factor commonly used for liquid fuels). Part of the petroleum is converted into naphtha that is used for non energy ends and one fraction is not emitted; this retention is subtracted separately. That is, the petroleum item is responsible for a large part of the TD accounting emissions. In the TD Extended process adopted in the Carbon Balance there are no emissions assigned to petroleum but they are assigned to its products in each sector where they are used. The non-oxidized fraction is also calculated based on the fuel (primary or secondary ) consumption in the sector where it is used (e.g. 1% of gasoline in road transport).

The carbon emission so calculated can be converted to CO2 as in the Top-Down process. The calculation has shown that the two methodologies are equivalent in terms of global emissions if emissions associated with losses and adjustments are considered [4].

 

2.3 Greenhouse Effect Emissions in the Bottom-Up by Coefficients Methodology

The option adopted in the Carbon Balance was to use energy/emission coefficients of specific gases (CO2, CO, CH4 and NMVOCs) taken from the Bottom-Up approach to account for their emissions.

For the Brazilian Initial Declaration to the United Nations Framework Convention on Climate Change (MCT, November 2004), the General Coordination of Global Climate Change – CGMGC/SEPED/MCT consolidated the inventory of emissions that contribute to the greenhouse effect. The inventory’s data were arranged [5] in the form of emission/energy coefficients where it was possible to obtain the emission of the different gases, using data from the National Energy Balance – BEN/MME, in mass of each one of them; then they were transformed in fractions of emitted carbon for each gas and applied to the carbon mass obtained by the mass/energy correspondence, as summarized below.

The emitted gases that contain carbon, except the NMVOCs, have a well known relationship between the carbon mass and the total one, namely:

CO2 →c1 = 12/44

CO   →c2 =12/28

CH4 →c3 = 12/16  

For the NMVOCs it was assumed a fraction of carbon mass (c4=0,85) based on the average emissions in industry.

If m1, m2, m3 and m4 are the masses of those emitted gases, one has the carbon mass conservation:

m1.c1 + m2.c2 + m3.c3 + m4.c4 = MC*(1-fnox-fret)

where, MC is the carbon mass in the fuel used in the sector minus the non oxidized fraction (fnox) and the retained one (fret).

In general, the fuel fractions chosen are those recommended by the IPCC taking into account some Brazilian peculiarities, most of them concerning biomass. In most cases it is 1% for liquids and 0.5% for gases. The non-oxidized fractions (energy products) and those retained (non-energy products) are shown in item 8. It should be noticed that the retention factor was supposed = 1(by default), that is 100% retention in the cases where its value is not known so that eventual non energy uses in previous years when emissions were not calculated may be detected[6].

Emissions of waste from alcohol production, composed mainly of CO2 from  the fermentation of molasses and sugarcane liquor, were also calculated.

The emission coefficients of the Bottom-Up process supplied by the staff of the Inventory Emissions were presented in the usual BEN structure. The Ministry of Mines and Energy supplies the Balance’s original data in an amplified structure of 49 “accounts” and 47 energy sources that was used in the Carbon Balance. The coefficients used for gases emissions were expanded and the values available for the aggregate as those of its components were adopted[7] so that this structure could be used.

The emission coefficients supplied by CGMGC/SEPED/MCT referred to energy balance data available at the time of the Inventory that still used the HCP ( high calorific power) concept and ton oil equivalent (old toe = 10800 Mcal) in the denomination adopted in the present report. The emitted carbon fraction was calculated using these data. The carbon mass fraction does not depend on the energy unit and the conversion to carbon mass is carried out for each energy source using the new values already adopted by BEN from 2003 on, base year 2002, using the low calorific power and 1toe = 10000 Mcal.

2.4 Biomass Treatment

The CO2 emissions are the main purpose of the present report since it has been detected that for different energy sources the sum of carbon atoms in emissions corresponded to values that exceeded 30% the carbon contained in the fuel. This is due to double inclusion that is somehow inherent to the IPCC approach where the CO2 emission data from the Top-Down approach are used as those of the Bottom-Up approach. This procedure produces some doubts concerning the results, since the emissions of other carbon compounds can be added to evaluate the greenhouse effect.

The option adopted here separates the emissions as it is supposed to happen in their origin. So the CO2, CO, CH4 and NMVOCs emissions are estimated so that the sum of carbon mass is equal to that contained in the fuel and subtracting the retained and oxidized carbon.

In the carbon balance approach it should be taken into account that in the production of the raw material the carbonic gas of the atmosphere is absorbed. The biomass production is therefore accounted for as “negative emission”. The inclusion of this negative emission makes it clear the role of biomass and its emissions avoiding the incorrect use of emissions from biomass[8].

However, in the sectorial evaluation it should be clear the separation between emissions from biomass and that from fossil fuel. An alternative adopted here in some cases is to represent the “negative emissions” referring to biomass production in the energy sector.

 

3. Carbon Emission

3.1 Data Aggregation and Chosen Years

A summarized picture of emissions expressed in carbon mass can be produced by choosing some sectors and grouping the energy sources. The following sectors were chosen:

·          Amplified energy sources (production, transformation and use in the energy sector);

·          Residential;

·          Commercial and Public;

·          Agriculture and Husbandry;

·          Transports and

·          Industrial.

 

The fuels were aggregated in:

·          Biomass;

·          Natural Gas;

·          Petroleum and Products of Petroleum and Natural Gas;

·          Mineral Coal and Products.

1994 (last year of the initial inventory) and 2005 (last year with data available from BEN) were chosen as reference years.

3.2 Emissions Calculation

The bal_eec software, developed by the ECEN Consultoria Ltda, was used for the emission calculation; it is a modification of the program previously developed for calculating the balance in equivalent energy.

The program was modified so that, besides the energy, equivalent energy and carbon balances, it could calculate emissions of the greenhouse effect gases CO2, CH4, NMVOCs, CO, NOx and N2O per energy source and per account.

The program permits to construct tables for the above mentioned gases using specific coefficients for the 1990/1999 period that are extrapolated for the other years. It can construct tables and graphics for the different accounts and energy sources for each one of the GHE gases.

The program also calculates emissions of greenhouse effect gases (CO2, CO, CH4, NMVOCs) from energy activities. Furthermore, it calculates emissions of nitrogen compounds that are of no interest for carbon balance but contribute to the greenhouse effect. The sum of the carbon contained in these gases is the carbon emitted to the atmosphere.

3.3 Sectorial Carbon Emissions

In Table 3.1 it is shown for the years 1994 and 2005 the sectorial emissions that contribute to the greenhouse effect (non-renewable sources).

The shares of the different sectors in the emissions of 1994 and 2005 are compared in Figure 3.1. The two more important sectors are Transport and Industrial that maintained their share, 40% and 31%, respectively. Transport and Industry are responsible for 71% of carbon emissions from energy activities. Of the other sectors, the energy one had a higher share (from 12% to 17%) and in absolute value its emissions have doubled from 1994 to 2005. The other sectors reduced their share in emissions, particularly the Residential one where emissions remained practically stable in absolute terms (4,200 Gg/year). The residential sector decreased its share from 7% to 5%. The growth of the energy sector was mainly due to the higher use of thermal energy that almost tripled in the considered period. The consumption growth in transport was headed by road transport. In Industry the sectors that contributed most to emissions were those connected with metallurgy, particularly pig iron, that grew 312% in the considered period.

Table 3.1 Carbon Emissions by Sector (Gg/year) 1994 and 2005

 

1994

Share

2005

Share

Variation

1994/
2005

Average

 Annual

 Variation

ENERGY SECTOR

7601

12%

15277

17%

101%

6.6%

NON USED

709

1%

1420

2%

100%

6.5%

 PUBLIC SERV. POWER PLANTS

1966

3%

5577

6%

184%

9.9%

AUTOPRODUCERS POWER PLANTS

1030

2%

2198

2%

113%

7.1%

ENERGY SECTOR CONSUMPTION

3897

6%

6083

7%

56%

4.1%

RESIDENTIAL               

4152

7%

4207

5%

1%

0.1%

COMMERCIAL                   

430

1%

514

1%

20%

1.6%

PUBLIC

517

1%

470

1%

-9%

-0.9%

AGRICULTURE AND HUSBANDRY

3415

5%

4037

4%

18%

1.5%

TRANSPORTS - TOTAL          

25422

40%

36876

40%

45%

3.4%

ROAD

22413

36%

33336

37%

49%

3.7%

RAILWAY

344

1%

472

1%

37%

2.9%

AERIAL

1695

3%

2097

2%

24%

2.0%

HYDROWAY

971

2%

971

1%

0%

0.0%

INDUSTRIAL - TOTAL           

19698

31%

27801

31%

41%

3.2%

CEMENT                      

1345

2%

2331

3%

73%

5.1%

PIG IRON AND STEEL

9688

15%

11889

13%

23%

1.9%

FERRO ALLOYS

76

0%

313

0%

312%

13.7%

MINING AND PELLETING

880

1%

1958

2%

122%

7.5%

NON FERROUOS AND OTH. METALURG.

1072

2%

2205

2%

106%

6.8%

CHEMISTRY

2481

4%

4020

4%

62%

4.5%

FOOD AND BEVERAGES

992

2%

1015

1%

2%

0.2%

TEXTILE

365

1%

314

0%

-14%

-1.4%

PAPER AND CELLULOSE             

805

1%

1033

1%

28%

2.3%

CERAMICS

687

1%

1031

1%

50%

3.8%

OTHER INDUSTRIES

1307

2%

1692

2%

29%

2.4%

NON ENERGY CONSUMPTION

1738

3%

1940

2%

12%

1.0%

TOTAL

62973

100%

91123

100%

45%

3.4%

 

Figure 3.1: Comparison of the sector’ shares in the emissions of greenhouse effect in 1994 and 2005

The largest share in Industry is that of the steel sector (pig iron and steel) that in 1994 was responsible for half of the emissions. There was a decrease in the shares of this activity but it still is the main responsible for emissions in Industry.

The carbon emissions variation (non-renewable sources) by sector can be seen in Table 3.2 and in Figure 3.2.

Table 3.2 Carbon Emissions by Sector, Non Renewable Sources,
 1970 /2005 Period in Gg/year

 

1970

1975

1980

1985

1990

1995

2000

2005

AMPLIFIED ENERGY SECTOR

3221

4006

5296

6470

6857

7978

13226

15277

NON USED

570

245

398

1051

684

709

1556

1420

PUBLIC SERV. POWER PLANTS

1181

1086

1429

1602

1630

2382

5041

5577

AUTOPRODUCERS POWER PLANTS

413

420

648

568

899

1118

1931

2198

ENERGY SECTOR CONSUMPTION

1057

2256

2821

3248

3645

3769

4698

6083

RESIDENTIAL               

1367

1701

2282

2961

3771

4343

4646

4207

COMMERCIAL                   

152

229

317

255

567

429

578

514

PUBLIC

80

167

215

152

139

551

573

470

AGRICULTURE AND HUSBANDRY

338

1043

1959

2538

2741

3662

3831

4037

TRANSPORTS - TOTAL          

10477

17847

19790

18914

22175

28116

33863

36876

ROAD

9030

14831

16425

14648

19203

24824

30155

33336

RAILWAY

377

457

520

505

443

369

338

472

AERIAL

575

1072

1402

1501

1589

1968

2571

2097

HYDROWAY

495

1487

1443

2261

940

954

799

971

INDUSTRIAL - TOTAL           

6545

11301

17636

14670

16250

20933

26897

27801

CEMENT                      

1051

1665

2110

1172

1529

1599

2843

2331

PIG IRON AND STEEL

2166

3015

5252

7112

7271

9900

11165

11889

FERRO ALLOYS

0

30

67

34

49

58

157

313

MINING AND PELLETING

194

501

856

599

661

889

1531

1958

NON FERROUOS AND OTH. METALURG.

136

265

599

794

857

1276

1758

2205

CHEMISTRY

710

1273

2468

2219

2349

2733

3896

4020

FOOD AND BEVERAGES

597

1051

1417

696

881

1110

1208

1015

TEXTILE

316

540

602

271

437

362

343

314

PAPER AND CELLULOSE             

389

726

1021

485

669

923

1164

1033

CERAMICS

278

590

871

379

461

732

912

1031

OTHER INDUSTRIES

708

1645

2374

910

1085

1351

1921

1692

NON ENERGY CONSUMPTION

13

215

459

1398

1537

1656

2052

1940

TOTAL

22194

36508

47954

47358

54036

67667

85666

91123

 

In Figure 3.2 it can be observed the effect of the second petroleum prices shock (1979) that lead to significant changes in fossil fuel consumption. The growth crisis at the beginning of the 2000s and the following petroleum price shock also affected emissions. The structural changes that were characterized by the Real Plan (1994) produced a significant growth in the Transport emissions (increase of the vehicle fleet and reduction of the alcohol share) as well as the already mentioned larger use of electric thermal generation.

Figure 3.2: Evolution of carbon emission from fossil sources where it can be noticed the  influence of the petroleum shock  on oil prices and on the economy

Table 3.3 Carbon Emissions by Sector, Non Renewable Sources and Biomass,
 1970- 2005 Period in Gg/year

 

1970

1975

1980

1985

1990

1995

2000

2005

ENERGY SECTOR

-36434

-35785

-33827

-35620

-29813

-26860

-22534

-33115

PRODUCTION

-41856

-44128

-46994

-58789

-53338

-51084

-49878

-68910

NON USED

639

456

446

1345

931

831

1564

1420

PUBLIC SERV. POWER PLANTS

1181

1086

1429

1627

1630

2382

5041

5603

AUTOPRODUCERS POWER PLANTS

531

589

992

1175

1614

2114

3335

4711

CHARCOAL PLANTS                   

1754

3664

4610

6460

6417

5067

4662

6112

DISTILLERIES                  

181

168

1076

3334

3290

3668

3122

4678

ENERGY SECTOR CONSUMPTION

1137

2379

4615

9229

9644

10162

9620

13270

RESIDENTIAL                  

21769

21186

18905

15233

12852

11242

11996

13424

COMMERCIAL                     

391

470

559

507

752

592

758

674

PUBLIC

96

176

226

165

145

573

573

470

AGRICULTURE AND HUSBANDRY

5466

5256

5337

5292

5014

5633

5542

6313

TRANSPORTS - TOTAL          

10599

17925

20901

22216

26738

33467

38397

42300

ROAD

9107

14898

17533

17947

23764

30176

34689

38760

RAILWAY

411

465

523

508

446

369

338

472

AERIAL

575

1072

1402

1501

1589

1968

2571

2097

HYDROWAY

506

1490

1444

2261

940

954

799

971

INDUSTRIAL - TOTAL           

15049

21824

30378

33299

34035

39932

47361

56056

CEMENT                       

1051

1665

2241

2105

1995

2003

3222

2799

PIG IRON AND STEEL

3456

6083

8913

11844

12680

14313

15699

17840

FERRO ALLOYS

62

142

309

556

497

530

752

1115

MINING AND PELLETING

194

501

900

713

704

889

1531

1958

NON FERROUOS AND OTH. METALURG.

148

319

676

962

1212

1499

1766

2215

CHEMISTRY

838

1426

2640

2611

2653

2956

3974

4093

FOOD AND BEVERAGES

5212

5760

6924

7370

6907

9289

10121

14535

TEXTILE

582

662

668

523

603

471

427

411

PAPER AND CELLULOSE             

734

1159

1978

2443

2780

3726

4678

5793

CERAMICS

1501

1962

2281

2353

2171

2261

2661

2860

OTHER INDUSTRIES

1271

2146

2847

1819

1835

1994

2531

2436

NON ENERGY CONSUMPTION

13

215

459

1398

1537

1656

2052

1940

TOTAL

16950

31266

42937

42490

51261

66233

84145

88062

In Table 3.3 the emissions by sector of the renewable sources and biomass from 1970 to 2005 (every 5 years) are presented. The biomass production is included with a negative sign in the emissions relative to biomass production. The calculated total is rather lower than the emissions of renewable sources because part of the captured carbon does not return to the atmosphere, according to the adopted retention hypothesis (due to non oxidizing and non energy use).

3.4 Carbon Emissions by Fuel Type

Figures 3.3 and 3.4 show the shares in the total emissions by type of fuel, including biomass, with indicative representation (transparent) that should not be accounted for in the calculation of greenhouse gases. It should be observed in the figures that the 1979 and the present petroleum price shocks have caused a return to the use of biomass whose historical trend has been that of reduction.

In Figures 3.5 and 3.6 the shares in carbon emissions are compared with shares in energy (measured as total energy supply) by energy of origin. It should be noted the vigorous penetration of natural gas. It is also noticeable the different shares of natural gas and mineral coal in emissions and energy, explained by the carbon content per energy unit, namely 15.3 tC/Tj for natural gas and 25.8 tC/Tj (69% larger) for mineral coal.

Figure 3.3: Total carbon emissions, including that of biomass that are presented as transparent to show that it does not contribute to the greenhouse effect 

Figure 3.4: Share of energy activities in the total carbon emissions where it is evident the effect of petroleum prices in the intensification of its use at the start of 1990s and 2000s

Figure 3.5: Share of fossil fuels in the generation of greenhouse effect gases, with percent indication for the year 2005

 

Figure 3.6: Share of fuels (energy)in the total energy supply; it should be noted the minor relative importance of coal and the major importance of natural gas relative to the previous  graphic (emissions)

In Figures 3.5 and 3.6 are shown the percent shares of fuels regarding emissions and energy in the last year (2005). For the petroleum and natural gas products they are equal (in the adopted approximation). For natural gas the energy share is 17%, higher than that of emissions (14%); the opposite occurs for mineral coal that has a share of 11% in energy and 16% in emissions. This difference is due to the coal’s higher carbon content per unit energy relative to natural gas.

Tables of emissions by fuel and sector in 2005 are shown in item 8 (total values). In item 8 are also shown the annual carbon balance (carbon content in fuels) and carbon emissions. The tables for all years are available at http://ecen.com.

Table 3.4 : Carbon Emissions, for the 1970 -2005 period
 by fuel, in Gg/year

 

1970

1975

1980

1985

1990

1994

1995

2000

2005

NATU RAL GAS

615

460

878

2301

2537

2999

3163

6542

12423

STEAM COAL

617

610

1291

2657

2068

2070

2077

2817

2360

MET. COAL

0

0

0

0

0

277

653

2634

3363

OTHER  NON RENEW.

44

39

95

178

287

259

258

679

833

DIESEL OIL

4675

8608

13451

14650

18009

20482

21887

25955

28691

FUEL OIL

6629

11906

15073

8255

9105

9931

10477

10119

6357

GASOLINE   

5834

8827

6940

4777

5863

7274

8699

10432

10681

LPG

974

1436

2169

2926

4054

4364

4621

5590

5076

NAPHTHA      

1

205

284

673

830

1031

1020

1359

1218

ILLUM. KEROSENE

403

395

356

223

155

98

82

45

20

AVIATION KEROSENE

513

1008

1343

1456

1550

1653

1929

2524

2063

REFINERY GAS

175

854

884

1301

1410

1670

1595

2143

2828

PETROLEUM COKE

0

0

0

435

445

618

737

3780

4353

OTHER .EN. PETRO.

38

81

709

461

546

704

881

1804

1768

PIPED GAS

99

130

171

219

211

106

90

64

0

ASPHALT

0

0

0

0

0

0

0

0

0

LUBRICANTS

0

0

0

310

292

268

282

344

358

SOLVENTS    

0

0

0

0

0

0

0

0

0

OTH. NON  EN. PET.

0

0

0

0

0

0

0

0

0

MIN. COAL COKE

1445

1959

3908

6040

6274

8221

8322

7953

7847

COKE OVEN GAS

170

226

402

692

736

813

821

769

790

OTH. SEC.  TAR

30

41

94

119

182

254

243

145

97

NON RENEWABLE

22262

36786

48049

47672

54553

63090

67838

85700

91126

FIREWOOD    

-6841

-9095

-9789

-12062

-11333

-9782

-9062

-8591

-10988

SUGARCANE LIQUOR

-68

-63

-1498

-5166

-5009

-4970

-4795

-3728

-5109

MOLASSES

-235

-218

-410

-695

-675

-884

-988

-1109

-1939

OTHERS

-1

-3

-36

-78

-66

-72

-61

-31

-115

BAGASSE

-394

-467

-853

-1471

-1417

-1825

-1807

-1716

-2756

BLACK LIQUOR

-1

-3

-7

-9

-11

-18

-18

-24

-36

OTHER RENEWABLE.

0

0

-29

-69

-55

-53

-43

-7

-80

CHARCOAL

1970

4115

5292

7659

7604

6607

6089

5964

7741

ETHYL ALCOHOL

77

67

1107

3299

4561

5175

5351

4534

5424

RENEWABLE WASTE

181

168

1076

3334

3290

3599

3668

3122

4678

RENEWABLE

-5314

-5499

-5148

-5259

-3113

-2222

-1666

-1587

-3179

TOTAL

16948

31288

42901

42412

51440

60868

66172

84113

87947

3.5 Summary of Carbon Emissions

Table 3.5 and Figure 3.7 summarize carbon emissions by sector and fuel type in the year 2005.

Table 3.5: Summary of Carbon Emissions for the 2005 year in Gg/year

 

NATURAL GAS

PETROLEUM AND NG PRODUCTS

MINERAL COAL AND PRODUCTS

RENEWABLE

TOTAL 

PRODUCTION + NOT USED

1420

0

0

-68910

-67489

 ELECTRICITY GENERATION

2576

3111

2088

2539

10314

OTHER TANSFORMATIONS

0

0

0

10790

10790

FINAL NON ENERGY CONSUMPTION

321

1577

43

0

1940

ENERGY SECTOR

2110

3805

168

7188

13270

RESIDENTIAL                  

122

4085

0

9217

13424

COMMERCIAL AND PUBLIC                

180

805

0

159

1144

AGRICULTURE AND HUSBANDRY

2

4035

0

2276

6313

TRANSPORTS

1090

35785

0

5424

42300

INDUSTRY

4603

11044

12158

28251

56056

TOTAL

12423

64245

14458

-3064

88062

Figure 3.7: Summary of Carbon Emissions in the year 2005 in Gg/year

 

4. CO2 Emissions

4.1 Carbonic Gas Accounting

The CO2 emissions are those with the highest mass involved and they give the largest contribution to the greenhouse effect due to their long stay in the atmosphere and they are the main subject of the present report. These emissions were those that had major corrections relative to the values of the Initial Inventory as the adjustments of excess emitted gas mass were made on the CO2 mass.

The option adopted in the Balance was to separate emissions as it is supposed to happen in the origin. Therefore the data cannot be directly compared with the CO2 mass calculated by multiplying the emitted carbon mass by 44/12.

It is taken into account that the gas is absorbed by the atmosphere in biomass production as raw material. In the accounting of greenhouse effect gases emissions this absorption should be accounted for as negative CO2 emission. The inclusion of this negative emission shows more explicitly the role of biomass and its emissions, avoiding the unjustified use of emissions from biomass.

However, in the sectorial evaluation it should be clear the separation between emissions from biomass and those from fossil fuels. An alternative, adopted here, is to represent “negative emissions” in the energy sector regarding biomass production.

4.2 Comparison with the Inventory Values

Comparisons with the Inventory values should be made based on emissions assigned to “non renewable” sources. This comparison is made in Table 4.1 for the years 1990 and 1994 and for the 1990/1994 period. Some considerable differences deserve comments:

·          In natural gas it was included emission due to the “non used” item (NG burning) that was considered as totally composed of CO2 in a preliminary approach. Fundamentally it is natural gas burned in the platforms or wells due to transportation difficulties or other operational reasons. If these emissions are not considered, the difference between the calculated value and that of the Inventory is 6%.

·          The discrepancy regarding gasoline exist because in the Inventory the CO2 emission corresponds to the total carbon contained in the fuel. As the carbon quantity emitted in the form of CO is 34.9%, besides 2.8% emitted in the form of CH4 , there is a overestimation of 40% in the sum of contained carbon. 

·       In coke oven gas there was a significant change in the mass/energy coefficient, as indicated in the e&e report relative to Goal 2 (issue N0 60 of the e&e periodical).

·          In general the emission values are lower (in 5%) than those of the Inventory because they do not consider the carbon fraction of the other emitted gases.

·          In the “Others” item there was a different allocation of energy sources.

Table 4.1: CO2 Emissions Calculated and Published in the Inventory –
Comparison by Energy Source - Non Renewable Sources - Unit: Gg/year

 

 

1990

 

 

1994

 

 

Average 1990

to 1994

 

 

e&e

INV

comp.

e&e

INV

comp.

e&e

INV

comp.

NATU RAL GAS

9291

6363

46%

10982

7945

38%

49630

35381

40%

STEAM COAL

7571

7634

-1%

7580

7650

-1%

39604

39963

-1%

MET. COAL

0

0

-

1014

1031

-2%

1687

1716

-2%

OTHER  NON REN.

1037

630

65%

938

585

60%

5552

3424

62%

DIESEL OIL

64405

65680

-2%

73283

75067

-2%

343216

351355

-2%

FUEL OIL

33274

32869

1%

36294

36366

0%

169153

168986

0%

GASOLINE    

12136

21620

-44%

19554

26825

-27%

77399

119633

-35%

LPG

14854

14445

3%

15992

16012

0%

76872

76471

1%

NAPHTHA      

3044

2982

2%

3780

3693

2%

16354

16014

2%

ILLUM. KEROSENE

567

568

0%

359

364

-1%

2367

2375

0%

AVIATION KEROSENE

5657

5677

0%

6033

6054

0%

29125

29227

0%

REFINERY GAS

4343

4126

5%

5870

5302

11%

25758

23747

8%

PETROLEUM COKE

1540

1574

-2%

2175

2183

0%

8757

8658

1%

OTH. EN. PETROLEUM

2003

2894

-31%

2581

3911

-34%

10577

15974

-34%

PIPED GAS

773

566

37%

389

302

29%

3163

2411

31%

ASPHALTS

0

0

-

0

0

-

0

0

-

LUBRICANTS

1070

1067

0%

981

978

0%

4877

4861

0%

SOLVENTS    

0

0

-

0

0

-

0

0

-

OTH. .NON  EN.PET.

0

0

-

0

0

-

0

0

-

MIN. COAL COKE

22918

22904

0%

30033

30012

0%

137740

137653

0%

COKE OVEN GAS

2608

5711

-54%

2877

6211

-54%

14101

30577

-54%

OTH. SEC. TAR

667

660

1%

928

918

1%

4482

4435

1%

NON RENEWABLE

187757

197970

-5%

221643

231409

-4%

1020413

1072861

-5%

In Table 4.2 the data by sector are compared with those of the Initial Inventory.

Table 4.2: CO2 Emissions Calculated (Non Renewable) and Published in the Inventory –  Comparison by Sector - Gg/year

 

 1990

 1994

Average 1990 to 1994

 

e&e

INV

comp.

e&e

INV

comp.

e&e

INV

comp.

ENERGY SECTOR

25085

22914

9%

27817

25602

9%

106264

98311

8%

NON USED

2508

0

-

2598

0

-

9630

0

-

PUBLIC  SERV. POWER PLANTS

5962

5999

-1%

7194

7242

-1%

28094

28308

-1%

AUTOPRODUCER  POWER  PLANTS

3278

3076

7%

3762

3607

4%

15820

15247

4%

ENERGY SECTOR CONSUMPTION

13337

13839

-4%

14263

14753

-3%

52720

54755

-4%

RESIDENTIAL                  

13818

13750

0%

15216

15176

0%

59338

59099

0%

COMMERCIAL                    

2078

2046

2%

1574

1557

1%

7047

6934

2%

PUBLIC

509

502

1%

1894

1962

-3%

3804

3859

-1%

AGRICULTURE AND HUSBANDRY

10043

9998

0%

12515

12516

0%

45519

45524

0%

TRANSPORTS - TOTAL          

70251

82020

-14%

84205

94324

-11%

313642

357125

-12%

ROAD

59584

71150

-16%

73399

83302

-12%

269992

312615

-14%

RAILWAY

1574

1614

-2%

1222

1260

-3%

6023

6210

-3%

AERIAL

5749

5818

-1%

6131

6204

-1%

23807

24068

-1%

HYDROWAY

3343

3437

-3%

3452

3558

-3%

13820

14232

-3%

INDUSTRIAL - TOTAL           

59442

61260

-3%

72050

74066

-3%

273769

281354

-3%

CEMENT                      

5594

5628

-1%

4918

4940

0%

21218

21334

-1%

PIG IRON AND STEEL

26569

28536

-7%

35401

37606

-6%

132622

140929

-6%

FERRO ALLOYS

178

208

-14%

278

281

-1%

958

946

1%

MINING AND PELLETING

2419

2405

1%

3218

3215

0%

11057

11027

0%

NON FERROUS AND OTH. METAL.

3138

3085

2%

3925

3860

2%

14596

14359

2%

CHEMISTRY

8607

8552

1%

9089

9038

1%

35460

35265

1%

FOODS AND BEVERAGE

3227

3201

1%

3633

3615

0%

14025

13937

1%

TEXTILE

1602

1599

0%

1339

1332

1%

5976

5935

1%

PAPER AND CELULLOSE              

2450

2445

0%

2948

2936

0%

11666

11629

0%

CERAMICS

1688

1680

0%

2514

2501

1%

8990

8961

0%

OTHER INDUSTRIES

3971

3921

1%

4786

4741

1%

17201

17032

1%

NON ENERGY CONSUMPTION

5634

5482

3%

6371

6204

3%

23203

22679

2%

TOTAL

186860

197972

-6%

221643

231408

-4%

832588

874885

-5%

4.3 Form of CO2 Balance Presentation

Table 4.3 summarizes for the year 2005 the emissions presentation form that takes into account the absorption of carbonic gas from the atmosphere by biomass that represents, in the adopted systematic, the negative emissions of carbonic gas. The production of renewable sources has a negative sign. Added to non used natural gas, one has emissions up to the energy balance line denominated total energy supply[9].

It could be expected that the non renewable column would be equal to zero since after biomass utilization it is supposed that the carbon returns to the atmosphere. However, it should be remembered that part of the biomass is not oxidized and would not return to the atmosphere (by the adopted systematic) as it happens with all fuels. The coefficients used for solid biomass have a typical value of 0.87 which means that 13% of the total processed would be permanently subtracted from the atmosphere[10]. In the CO2 accounting one should also consider that part of the carbon was substituted in the atmosphere by other compounds that contain carbon and in the long term they are transformed into CO2. In the data of Table 4.3 the quantity that did not return to the atmosphere in the form of carbonic gas is about 8% of the removed mass.

Tables with similar details as those of the Annual Energy Balance are presented in item 8 at the end of the present report.

 Table 4.3: Summary Table of CO2 Emissions in the Year 2005

ACCOUNT

RENEWABLE

PETROLEUM, NG  PRODUCTS
 + OTH.

MINERAL COAL PRODUCTS

NON RENEWABLE

TOTAL

PRODUCTION

-195375,2

0,0

0,0

0,0

-195375,2

NON USED

0,0

2598,0

0,0

2598,0

2598,0

SUM (TOTAL ENERGY SUPPLY) 

-195375,2

2598,0

0,0

2598,0

-192777,2

TOTAL TRANSFORMATION

34063,6

6460,0

4496,4

10956,4

45020,0

FINAL  CONSUMPTION

137212,1

163857,6

37862,5

201720,2

338933,3

FINAL NON ENERGY CONSUMPTION

0,0

1,0

2,0

3,0

4,0

FINAL ENERGY CONSUMPTION

137212,1

163856,6

37860,5

201717,2

338929,3

ENERGY SECTOR

23668,3

13502,1

760,7

14262,8

37931,1

RESIDENTIAL                   

22562,5

15216,1

0,0

15216,1

37778,6

COMMERCIAL                    

571,2

1574,2

0,0

1574,2

2145,4

PUBLIC

13,8

1893,7

0,0

1893,7

1907,5

AGRICULTURE AND HUSBANDRY

6201,4

12515,2

0,0

12515,2

18716,6

TRANSPORTS - TOTAL          

16005,4

84204,9

0,0

84204,9

100210,3

INDUSTRY - TOTAL           

68189,4

34950,4

37099,8

72050,2

140239,6

TOTAL

-24099,5

172915,6

42359,0

215274,5

191176,0

4.4 Evolution of CO2 Emissions by Fuel

Table 4.4 summarizes CO2 emissions for chosen years in the 1970/2005 period. Figure 4.1 shows the evolution of CO2 emissions separated in renewable and non renewable sources. It should be noted that the negative value for renewable sources is justifiable by the adopted criteria, namely assign as negative the “emissions” in the biomass production.

                Figure  4.1 CO2 emissions for renewable and non renewable sources where it can be noticed the negative values for renewable ones due to carbon absorption by the atmosphere which is not completely compensated by emission in the energy use due to partial retention (non oxidized or non energy applications) and due  to carbon emitted as another form of gas

 

Table 4.4: CO2 Emissions by Fuel for the 1970/2005 Period in Gg/year

 

1970

1975

1980

1985

1990

1995

2000

2005

NATURAL GAS

2254

1686

3216

8428

9291

11581

23945

45431

STEAM COAL

2261

2147

4654

9655

7571

7607

10321

8649

MET. COAL

0

0

0

0

0

2391

9642

12309

OTHER  NON REN.

160

141

344

642

1037

935

2464

3016

DIESEL OIL

16707

30768

48097

52422

64405

78317

92831

102607

FUEL OIL

24241

43485

55108

30078

33274

38298

37000

23206

GASOLINE    

12082

18272

14370

9893

12136

23388

28049

28723

LPG

3570

5264

7948

10722

14854

16934

20483

18598

NAPHTHA      

4

596

939

2467

3044

3739

4983

4467

ILLUM. KEROSENE

1477

1445

1303

816

567

302

166

74

AVIATION KEROSENE

1871

3680

4904

5313

5657

7040

9212

7531

REFINERY GAS

501

2416

3143

3746

4343

5466

7839

10355

PETROLEUM COKE

0

0

0

1595

1540

2524

13765

15951

OTH. EN. PETROLEUM

138

298

2599

1690

2003

3230

6613

6480

PIPED GAS

364

477

628

803

773

329

236

0

ASPHALTS

0

0

0

0

0

0

0

0

LUBRICANTS

0

0

0

1135

1070

1034

1261

1313

SOLVENTS    

0

0

0

0

0

0

0

0

OTH. .NON  EN.PET.

0

0

0

0

0

0

0

0

MIN. COAL COKE

5279

7155

14276

22065

22918

30403

29054

28656

COKE OVEN GAS

511

764

1390

2471

2608

2931

2785

2890

OT.SEC.  TAR

112

151

346

436

667

882

532

354

NON RENEWABLE

71532

118747

163265

164377

187757

237333

301182

320608

CHARCOAL   

-43715

-51584

-51947

-58114

-52716

-42071

-40429

-51529

SUGARCANE LIQUOR

-251

-233

-5494

-18943

-18368

-17582

-13668

-18734

MOLASSES

-863

-801

-1505

-2548

-2474

-3623

-4068

-7108

OTHER RENEWABLE

-7

-12

-140

-325

-289

-268

-169

-506

SUGARCANE BAGASSE

-1853

-2199

-4014

-6918

-6663

-8498

-8069

-12962

BLACK LIQUOR

-6

-12

-32

-42

-49

-76

-104

-153

OTH. RECOV. RENEW.

-1

-1

-107

-283

-239

-192

-65

-353

CHARCOAL

6636

13926

17912

25997

25856

20720

20297

26348

ETHYL  ALCOHOL

231

203

3344

9961

13771

16550

14022

16776

RENEWABLE WASTE

664

616

3944

12223

12062

13450

11447

17153

RENEWABLE

-39164

-40096

-38040

-38989

-29108

-21591

-20806

-31069

TOTAL

32368

78651

125225

125388

158649

215742

280376

289540

 

4.5 Evolution of CO2 Emissions by Sector (Account)

Sectorial emissions can be represented without including those from renewable sources or including them. In Figure 4.2 are presented sectorial emissions with and without renewable sources. Tables 4.5 and 4.6 summarize these data for chosen years in the 1970 /2005 period. 

(a)

(b)

Figure 4.2: CO2 emissions considering or not renewable sources; it should be noticed that the total emission curves have a much close shape in the two cases and the curve that includes renewable sources is slightly lower


 

Table 4.5: CO2 Emissions by Sector (Including Renewable)
for the 1970/2005 Period  in Gg/year

 

1970

1975

1980

1985

1990

1995

2000

2005

ENERGY SECTOR

-134759

-133882

-126836

-135960

-114478

-102521

-85894

-125843

PRODUCTION

-153473

-161802

-172311

-215561

-195574

-187309

-182887

-252668

NON USED

2092

899

1460

3854

2508

2598

5707

5208

PUBLIC SERV. POWER PLANTS

4324

3976

5229

5865

5962

8711

18449

20486

AUTOPRODUCERS POWER PLANTS

1930

2138

3597

4236

5836

7655

12084

17021

CHARCOAL PLANTS                   

5553

11597

14593

20448

20312

16040

14756

19347

DISTILLERIES                  

664

616

3944

12223

12062

13450

11447