Quality control of completeness

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The CO2 completeness check (Section 1.4.3.1) starts from energy balance data and is designed to check that all significant emissions of CO2 from the first non-energy uses of fossil fuels are reported somewhere in the inventory, without double counting. The emissions are the sum of CO2 emissions from (a) fuels used as feedstock in the chemical industry, (b) fuels used as reductant in the metal industry, (c) fuel products oxidised during use (partly or fully; direct emissions or emissions of carbon containing non-CO2 gases (NMVOC, CO and CH4) oxidised in the atmosphere).

Subsequent CO2 emissions may occur in the waste phase if the waste oils or waste products are incinerated. However, the amount of fossil-carbon containing products disposed of annually as waste is not equal to the amount used annually for first uses because fossil-carbon containing products may be imported or exported or they may be used for several years before they are discarded. The complications which arise from external trade hold equally for emissions resulting from the use of products made from feedstocks and their derivatives. Since derivative products may also be imported or exported the emissions from their use (e.g., from ethylene oxide or acrylonitrile production) cannot be linked directly to the first non-energy use of fossil fuels. For these reasons the CO2 completeness check is limited to the first non-energy uses of fossil carbon which lead to emissions and does not include CO2 emissions from waste incineration. Other non-energy sources of fossil CO2 are flaring, venting and other fugitive emissions in the Category 1B and are also excluded from this completeness checking method.

The feedstock balance check (Section 1.4.3.2) is simpler in concept and starts from non-energy statistics for feedstock/reductant supplies and compares them with the reported (or implied) requirements for feedstock by the various IPPU processes. This check identifies discrepancies between the two sets of data that may indicate omitted processes or feedstock use classified as fuel combustion.

1.4.3.1 CO2 COMPLETENESS CHECK

The principle of this method is based on comparisons of reported CO2 emissions with potential CO2 emissions from the fuel for non-energy uses and consists of three steps:

1. CO2-equivalent carbon contents are calculated for the non-energy use of fossil fuels as reported in national energy statistics (including the coke and other solid fuel inputs into blast furnaces).

2. Total CO2 emissions reported per IPPU subcategory are related to (main) fuels used for non-energy purposes. This should include emissions from by-product fuels transferred from the IPPU Sector and reported elsewhere in the Energy Sector.

3. Total reported fossil IPPU CO2 emissions are compared with a top-down estimate of potential CO2 of the carbon content of the feedstocks used. The comparison is made by calculating the actual CO2 released as a fraction of the total potential CO2 in the input fuels. The fractions may then be compared with values observed for different industries (see below, 'Step 3: Actions arising from the comparison'). In case of significant discrepancies, likely causes of differences should be listed, taking into account the accuracy of the allocation of sources to individual fuels.

Step 1: Feedstock amount and CO2-equivalent carbon content

The amount of feedstock and non-energy use entered in Table 1.3 is the final consumption of each fuel for 'non-energy' purposes as reported in the national energy statistics. The quantities should be expressed in, or converted to, Terajoules (TJ) using the net calorific (lower heating) values (see Chapter 1 of Volume 2 for IPCC default values). Next the potential CO2-eq. emissions associated with the carbon contents can be calculated using country-specific or IPCC default carbon content values (see Chapter 1 of Volume 2 for IPCC default values).

If a country accounts separately for the production of by-product gases from chemical production processes in their energy statistics, these should also be added in the top row of fuel amounts associated with feedstock emissions of CO2 and the corresponding amount of CO2-eq. calculated using country-specific carbon content values.

Step 2: Allocating source category CO2 emissions to one or more feedstock fuels

The CO2 emissions reported in the IPPU Sector that arise mainly from the metal and chemical industries, should be allocated to the corresponding fuel types used as input for the process. Emissions resulting from the non-energy use of fossil fuels reported elsewhere should be included here too. Guidance for this allocation is provided in Table 1.3, where for each subcategory the most common feedstock fuel is marked as a bolded box. Other fuels that are known to be used as feedstock for these sources are indicated with a regular box. In most cases these boxes are the only allocations to be checked for the country-specific application. If no specific information is available, all CO2 emissions may be assigned to the bold box. Where country-specific information shows that several fuels are used as feedstock, either the specific fractions for each fuel can be used or each may be given an equal share of the source total.

Step 3: Actions arising from the comparison

The fraction of potential CO2 actually released may be calculated per fuel type or per group of fuels, and can be assessed for their level, trend and interannual variation. The values of the fractions may be compared with values inferred from the information provided for the methodological tiers for the source categories or from literature (e.g., Neelis et al., 2005).

Small differences or changes may be expected due to process-specific technological or operational differences. Major differences can arise from large differences in technologies or, when comparing with other countries' data or literature, from the use of a different definition of feedstocks (for details see Section 1.3). A third explanation of discrepancies may be due to errors in the presumed allocation of source category emissions to specific fuel types used as feedstock in the process.

Table 1.3 Verification of completeness of reported C02 from non-energy use of fossil fuels

NOTES

Solids

1

Year:

Unit

Coal

Coke

Coal tars

Coal oils BF/OF gas (CO gas) b) Total solids

2

A: Declared NEU (from commodity balance)

TJ

1 1 1 1 1 ■ i i i i i M

C: Total supplied for feedstock/non-energy

[C = A * B

/ 1000]

kgC/GJ GgC

4

D: Total supplied for feedstock/non-energy

[D=C * 44/12]

Gg CO,-eq.

5

E: Implied carbon fraction oxidised

[E = f / D

* 1001

».

Activity a)

CO, Emissions a)

6

f: Total fossil IPPU C02 reported

GgCO,

2 INDUSTRIAL PROCESSES

GgCO,

7

2A: Mineral Industry

GgCO,

(Please specify the subcategory.)

GgCO,

7

2B: Chemical Industry

GgCO,

2B1: Ammonia Production

GgCO,

2B5: Carbide Production

GgCO,

2B6: Titanium Dioxide Production

GgCO,

2B8: Petrochemical and Carbon Black Production

GgCO,

2B8a: Methanol

GgCO,

2B8b: Ethylene

GgCO,

2B8f: Carbon Black

GgCO,

2B10: Other

GgCO,

1 1 1 1 1 1

7

2C: Metal Industry

GgCO,

2C1: Iron and Steel Production

GgCO,

1 1 1

2C2: Ferroalloys Production

GgCO,

2C3: Aluminium Production

GgCO,

2C5: Lead Production

GgCO,

2C6: Zinc Production

GgCO,

1 1 1 1 1 1

2C7: Other

GgCO,

III 1 1 1

7

2D: Non-Energy Products from Fuels and Solvent Use

GgCO,

i i i i

2D1 : Lubricant Use

GgCO,

1 1 1

2D2: Paraffin Wax Use

GgCO,

1 1 1

2D3: Solvent Use

GgCO,

1 1 1

2D4: Other

GgCO,

1

7

2H: Other

GgCO,

1 1 1 lili

2H1 : Pulp and Paper Industry

GgCO,

2H2: Food and Beverage Industry

GgCO,

2F3: Other

GgCO,

1

EXCEPTIONS REPORTED ELSEWHERE

GgCO,

7

1A FUEL COMBUSTION ACTIVITIES

GgCO,

i

lili lili

1 Ala: Main Activity Electricity and Heat Production

GgCO,

i

l l l l lili

lAlb: Petroleum Refining

GgCO,

lili

lAlc: Manufacture of Solid Fuels and Other Energy Industries

GgCO,

lili

1A2: Manufacturing Industries and Construction

GgCO,

1

1 1

1

lili

a) Same Activity Data and emissions as in sectoral background table (also for Activity Data NE, NO, C, and for emissions NE, NO, IE, where applicable).

b) To be included only if coke production is reported as part of integrated iron and steel production. 1: To be specified per year

2: Cf. Auxiliary worksheet for CO2-Reference Approach to subtract the NEU from total apparent consumption 3: IPCC default or country-specific values

4: So-called potential emissions, i.e., carbon embodied in the feedstock/non-energy fuels expressed in C02-eq.

5: Ratio of C02 emissions (direct emissions reported as well as atmospheric inputs of C02 from other carbon (non-C02)) at some aggregation level (by detailed fuel type or by major fuel type) to total potential C02 in the feedstock NEU fuels consumed 6: Sum of subcategories below including IPPU sources allocated to Fuel Combustion Activities 1A (due to transfer of by-product fuels to another source category (and IB, 4C when appropriate)) 7: Sum of subcategories of that category

Table 1.3 (Continued) Verification of completeness of reported C02 from non-energy use of fossil fuels

Naphtha Gas oil Fuel Oil Ethane LPG b) Petcoke Other Chem. gas Lubricants Waxes Bitumen Total liquids

Nat Gas

A: Declared NEU (from commodity balance) TJ

1 1 1 1 1 1 1 H H 1 1 1 1 1 1 1 1 II ■

B: Carbon Content kg C/GJ C: Total supplied for feedstock/non-energy [C = A * B / 1000] Gg C

D: Total supplied for feedstock/non-energy E: Implied carbon fraction oxidised

[D = C * 44/12] [E = F / D * 1001

%

Activity a)

C02 Emissions a)

F: Total fossil IPPU COz reported

GgCO:

2 INDUSTRIAL PROCESSES

Gg CO,

2A: Mineral Industry

Gg CO,

(Please specify the subcategory.)

Gg CO,

2B: Chemical Industry

Gg CO,

2B1: Ammonia Production 2B5: Carbide Production 2B6: Titanium Dioxide Production 2B8: Petrochemical and Carbon Black Production 2B8a: Methanol 2B8b: Ethylene 2B8f: Carbon Black 2B10: Other

Gg CO, Gg CO, Gg CO, Gg CO, Gg CO, Gg CO, Gg CO, Gg CO,

! ! ! 1 1 ! ! ! !

Ill

■ ! ! 1 ! ! ! !

2C: Metal Industry

Gg CO,

2C1 : Iron and Steel Production 2C2: Ferroalloys Production 2C3: Aluminium Production 2C5: Lead Production 2C6: Zinc Production 2C7: Other

Gg CO, Gg CO, Gg CO, Gg CO, Gg CO, Gg CO,

2D: Non-Energy Products from Fuels and Solvent Use

Gg CO,

2D1: Lubricant Use 2D2: Paraffin Wax Use 2D3: Solvent Use 2D4: Other

Gg CO, Gg CO, Gg CO, Gg CO,

1 1 ! ! 1=1

2H: Other

Gg CO,

1 i 1 1

2H1 : Pulp and Paper Industry 2H2: Food and Beverage Industry 2F3: Other

EXCEPTIONS REPORTED ELSEWHERE

Gg CO, Gg CO, Gg CO, Gg CO,

1A FUEL COMBUSTION ACTIVITIES

Gg CO,

1A1 a: Main Activity Electricity and Heat Production 1 Alb: Petroleum Refining lAlc: Manufacture of Solid Fuels and Other Energy Industries 1A2: Manufacturing Industries and Construction

Gg CO, Gg CO, Gg CO, Gg CO,

Note: In the tabular part, bolded boxes mark the main fuels as feedstock or reductant for the processes at the left hand side. Regular boxes mark other known feedstock/reductant for the processes at the left hand side.

1.4.3.2 Feedstock balance check

The principle of the feedstock balance check method is to compare the supply of feedstock/reductants as reported in national fuel statistics with the requirements for the feedstocks by each of the processes using them. A significant difference between the supply and the requirements of a feedstock leads to several suggested actions intended to identify omission of feedstock uses from the inventory or uses of fuel as feedstock that have been reported as fuel consumption or conversion.

Unlike the CO2 completeness check the feedstock balance check is conducted at the level of fuel quantities and not CO2 emissions. The method seeks confirmation that all feedstock carbon has been satisfactorily attributed to source categories identified in the inventory.

The workings of the method are explained below and readily set out in a worksheet (Table 1.5a). A list of feedstock fuels to be considered is presented in Table 1.4.

Table 1.4

List of fossil fuels that can be used as chemical feedstock or reductant

Solids

Liquids

Gases

Other fuels

coal metallurgical coke* petroleum coke* coal tars and oils*

refinery gas naphtha Ethane kerosene propane gas oil butane fuel oil LPG waste oils

natural gas

other fuel waste (fossil carbon)

* Includes uses as electrodes.

Step 1: Feedstock supply

Figures for supply of each feedstock/reductant are taken from national fuel statistics presented in commodity or energy balances. They will be shown as non-energy use or feedstock use according to the country's particular conventions and reductants as inputs to a transformation process. The quantities should be expressed in, or converted to, Terajoules (TJ) using net calorific (lower heating) values (see Chapter 1 of Volume 2 for IPCC default values).

The definitional basis for feedstock reporting differs between countries and this consideration is fully discussed in Sections 1.2.1 and 1.3.2. Some care is therefore needed to identify and use the correct hydrocarbon input figures that will correspond with a process's gross hydrocarbon requirements for the feedstock or reductant (including inputs not or only partly labelled as non-energy use in energy statistics). The total hydrocarbon process input attributed to feedstock/reductant use is required for the feedstock balance check described here, because the Specific Feedstock Consumption (SFC) figures of each process, as given in the table, include the fuel requirement. The SFC is the amount (expressed in TJ/Gg) of feedstock/reductant required per tonne of product produced.

Step 2: Feedstock requirements

The feedstock requirements of each process will include fuels taken directly or indirectly from the feedstock. Where the necessary data are available from industry sources they can then be entered into the 'requirements' part of the worksheet. Where the data are not available the requirements should be calculated from the production figures for the processes and where necessary, using expert judgement based on the emissions estimation used for the process(es). The figure for the process requirement is likely to be identical to the quantity supplied (taken from energy statistics) only when the latter has been obtained from industry sources.

When requirements are calculated from production using the spreadsheet the production figures are those relevant to the process for the given feedstock. If two or more feedstocks supply a single process then the corresponding production figures should be used for each feedstock.

Table 1.5b provides SFC factors linking production figures to feedstock requirements. The factors are the specific feedstock requirements of the process and include fuel use of the feedstock. The factors provided in Table 1.5b have been derived from the methods described in this volume of these Guidelines and may be considered as default values. It is good practice to use national factors if they are demonstrably more relevant than the default factors given here.

If Rij represents the feedstock requirements of process i for feedstock j, then the total requirement for feedstock j (R,), can be expressed as:

Equation 1.1 Total feedstock requirement

Where:

Rj = total requirement for feedstockj, TJ

RiJ = feedstock requirements of process i for feedstock j, TJ

SFCiJ = Specific Feedstock Consumption of feedstock j in process i, TJ/Gg

Pjj = production from process i using feedstock j, Gg

The Rj is then compared with the figure for the supply of feedstock j. The difference appears in the Table 1.5a. The implementation procedure for this check is set out in the flowchart in Figure 1.3.

Step 3: Actions arising from the comparison

It is suggested that if the difference observed exceeds 10 percent of the feedstock supply action should be taken to check the data and, if the difference is confirmed, it should be investigated. The 10 percent threshold is necessarily arbitrary and chosen to reflect the likely overall inherent uncertainties in the data.

It is considered good practice to focus the investigation on differences in which feedstock supply significantly exceeds the apparent requirements because this suggests that:

• Processes and therefore sources of emissions may have been omitted; or

• The specific energy requirements used in the method are too low. The specific energy requirements should then be adjusted to reflect the national situation.

When the calculated requirements exceed the apparent feedstock supply it suggests that:

• Uses of feedstock fuels are reported elsewhere as fuel combustion or fuel conversion uses.

• A 'net' definition of feedstock supply may have been used in the energy statistics instead of a 'gross' definition (see the reference to ethylene and other chemicals in Section 1.3.2).

• Feedstock requirements, obtained directly from industry sources, are overstated through the inclusion of fuels entering the plant (or more generally, the source category) which are not used in the process and therefore not for feedstock use. The inclusion of non-feedstock fuels should not occur when the feedstock requirements are derived from production data.

Where significant discrepancies remain the likely causes of differences should be listed, taking into account the accuracy of the calculation with default Specific Feedstock Consumption values per source category/feedstock combination.

Table 1.5a Comparison of feedstock supply with requirements implied by production

Table 1.5a is a reduced form of the full table in which the tabular part is replicated as many times as there are types of feedstock or reductant. In each of the replications the 'Feedstock or Reductant' heading in column 1 is replaced by the name of the fuel. The corresponding SFC values are then entered in column 2. The default SFC values are given in Table 1.5b below.

An Excel workbook is provided in the 2006 Guidelines CDROM containing the full table, the default values and the formulae to carry out automatically the requirements calculation.

Table 1.5a Comparison of feedstock supply with requirements implied by production

(TJ) (TJ/Gg)

Feedstock Quantity delivered

Difference

Ammonia prodn m Silicon carbide g Calcium carbide E Ethylene J= Methanol C Carbon black Other

Va fr Tabl

lues am e 1.5b

Iron and steel s Ferroalloys tlas Aluminium

| Zinc Lead Other

1

r

Table 1.5b Specieic Feedstock Consumption (TJ/Gg) for feedstock/reductants

Coal

Met coke

Pet Coke

Coal tars and oils

Ref gas

Ethane

Propane

Butane

LPG

Naphtha

Kerosene Gas oil Fuel oil

Waste oils Natural gas

Ammonia prodn

43(l)

38(o)

Silicon carbide

37(e)

05

Calcium carbide

21(f)

E

Ethylene

58®

100(k)

104(k)

102(k)

137(k)

O

Methanol

72(a)

37(m)

34 (p)

Carbon black

60(h)

60(n)

12(q)

Other

Iron and steel

10(b)

w 03

Ferroalloys

Aluminium

12(g)

3(i)

0)

Zinc

21(c)

Lead

7(d)

Other

(a) Methanol: From Section 3.9.2.2; Table 3.13 Consult table for precise value according to process used.

(b) Iron and Steel: From Section 4.2.2.3: "The conversion factors provided in Table 6.2 of the IPPC Document are 940 kg pig iron per tonne liquid steel and 358 kg coke per tonne pig iron." so coke requirement is 0.358 x 28.2 GJ/tonne (cv coke) = 10 GJ/tonne iron.

(c) Zinc: From Section 4.7.1 (pyrometallurgical process only) taken from Sjardin(2003) Coke consumption is 0.74 tonnes coke/tonne zinc. That is: 0.74 x 28.2 GJ/tonne (cv coke) = 21 GJ/tonne zinc.

(d) Lead: Taken from Sjardin(2003) Coke consumption is 0.26 tonnes coke/tonne lead. That is: 0.26 x 28.2 GJ/tonne (cv coke) = 7 GJ/tonne lead.

(e) Silicon carbide: From Section 3.6.2.2: "This implies a typical emission factor of 2.3 tonnes C02/tonne petroleum coke used (IPCC, 1996), or 2.62 tonnes C02/tonne carbide produced." So coke requirement is 2.62/2.3 = 1.14 tonne pet coke/tonne carbide. That is; 1.14 x 32.5 GJ/tonne (cv pet coke) = 37 GJ/tonne SiC.

(f) Calcium carbide: From: Section 3.6.2.2 "1 750 kg limestone (or 950 kg CaO), 640 kg of petroleum coke and 20 kg carbon electrodes are required to produce 1 tonne of carbide." So coke requirement is 0.64 x 32.5 GJ/tonne (cv pet coke) = 21 GJ/tonne CaC2.

(g) Aluminium: From Section 4.4.2.2; Table 4.11 average of two processes 1.65 tonnes C02/tonne Al = 0.45 tonnes C/tonne Al. Assume anodes contain 84% coke and 16% pitch. (Sjardin 2003). Assume coke is 92% C and pitch is 93% C. Assume NCV for calcined coke is 30 MJ/kg and NCV for pitch 35.6 MJ/kg.

Then coke requirement is 12 GJ/tonne Al and pitch requirement 3 GJ/tonne Al.

(h) Carbon black: Assumed identical to fuel oil. See note (n) below.

(j) Ethylene: From Section 3.9.2.3; Table 3.25 Ethane requirement is: NCV for ethane x 1/yield matrix value. That is: 46.4 x 1/0.803 = 58 GJ/tonne. (k) Ethylene: Feedstock requirement can be derived as is derived for ethane. See note (j) above. (I) Ammonia: From Section 3.2.2.2; Table 3.1 ;Partiai oxidation assumed.

(m) Methanol: From Section 3.9.2.2; Table 3.13. Consult table for precise value according to process used.

(n) Carbon Black: Based on Voll etal. (1997) and EU Integrated Pollution Prevention and Control (2004), Table 4.13.

(p) Methanol: From Section 3.9.2.2; Table 3.13;Consult table for precise value according to process used.

(q) Carbon Black: Based on Voll etal. (1997) and EU Integrated Pollution Prevention and Control (2004), Table 4.13.

Figure 1.3 Flowchart for verification of completeness of accounting for non-energy uses of fuels

Figure 1.3 Flowchart for verification of completeness of accounting for non-energy uses of fuels

Note:

Rij = feedstock requirements of process i for feedstock j, TJ

SFCij = Specific Feedstock Consumption of feedstock j in process i, TJ/Gg

Pij = production from process i using feedstock j, Gg

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