铁和钢生产碳排放量英文用户指南Iron and Steel Version 2.0 Guidance.docx

Calculating Greenhouse Gas Emissions from Iron and Steel ProductionA component tool of the Greenhouse Gas Protocol InitiativeJanuary 2008.For additional information please contact Stephen Russell ()3. Coke production4. Flaring3.2.1 Emissions firom Electricity Generation and Reheating FurnacesCO2The calculation of CO2 emissions from Electricity Generation and Reheating Furnaces requires data on the carbon content, heating value and oxidation fraction of the consumed fuel(s). Default, Tier 1 values fbr each of these factors are supplied.The following sections provide information on these factors and on how the fuel consumption data should be gathered.Fuel Consumption DataEquation 1Facilities need to collate data on the amount of fuel consumed over the reporting year and disaggregate these data by fuel type. These data can come directly from on-site metering of the fuel inputs into the combustion units or from the output of these units. Alternatively, the data may be calculated from purchase or delivery records, in which case companies should be careful to account fbr inventory stock changes following Equation 1:Accounting for Changes in Fuel StocksTotal Annual Fuel Consumption = Annual Fuel Purchases - Annual Fuel Sales + Fuel Stock at Beginning of Year - Fuel Stock at End of YearFuel Carbon Content and Heating ValuesThe carbon content of a fuel is the fraction or mass of carbon atoms relative to the total mass or number of atoms in the fuel; it is thus a measure of the potential CO2 emissions from that fbel's combustion.The carbon content of a given fuel can show variation over space and time (see Figure 2 for an example). The extent of variation can depend on the units chosen to express the carbon content data - less variability is often seen when the data are expressed on an10energy basis (e.g.9 Kg carbon/MJ or tonnes carbon/ million Btu) compared to a mass or volume basis (e.5 kg C/ Kg fuel). Carbon content values can be converted to energy units using heating or calorific values.Figure 2. Spatial variation in the carbon content of pipeline-quality natural gas in the U.S.Source: Energy Information Administration (1994), Emissions of Greenhouse Gases in the United States 1987-1992.(ruguoqsb) ED 一出 X8 Euwo。uo£b。A fuefs heating value is the amount of heat released during the combustion of a specified amount of that fuel (example units are MJ/Kg? thousand Btu/lb, and MMBtu/bbl). Two alternative metrics of heating value may be used to adjust carbon content data: lower heating value (LHV; also known as Net Calorific Value (NGV) and higher heating value (HHV; also known as Gross Calorific Value (GCV). These metrics differ in how they consider the different physical states (liquid or gaseous) that water exists in following combustion. The HHV includes the latent energy of condensation of water following combustion, whereas the LHV is obtained by subtracting the heat of vaporization of the water produced by combustion from the higher heating value. More specifically:11Equation 2Inter-converting HHV and LHV dataLHV=HHV- 0.21277 -0.0245M -0.0087Where:M = % moistureH = % hydrogenY = percent oxygenA commonly accepted approximation fbr inter-converting LHV and HHV data is to assume that the LHV is 95% of the HHV for solid fuels, such as coal and oil, but 90% of the HHV fbr gaseous fuels, such as natural gas.One benefit of the HHV over the LHV is that the relationship between carbon content and heating values is more direct using the former. This is because the LHV is partly a function of the filer s moisture content, which can vary significantly. In North America the convention is to use HHV, whereas LHV is used outside North America.Carbon content factors can be converted to an energy scale using heating values with Equation 3:Equation 3Converting carbon content factors from a mass or volume basis to an energy basisFcHVfWhere:Fgh = Carbon content of fuel on a heating value basis (e.g.，short tons carbon / millionBtu or metric tons carbon / GJ)Fc = Carbon content of fuel on a mass or volume basis (e.g.9 short ton carbon / short ton)HVf= Heating value of fuel (e.g.5 MJ/Kg5 thousand Btu/lb or MMBtu/bbl, etc.)To summarize, given the variability that can exist in fuel composition, companies are encouraged to use Tier 35 facility-specific values fbr carbon content and heating values whenever possible. Ideally, the carbon content factors should be expressed on an energy scale using higher heating values. Tier 3 information may be available from suppliers or from the Material Safety Data Sheets fbr purchased fuels. Tn case facility-specific values can not be derived, plants may use the Tier 1 default values in Appendix I. Companies may use a mix of plant-specific and default values in a single calculation (e.g.，custom carbon content factor, but default HHV data). Tier 2 values may be available from national statistical agencies and other national-level organizations.12Fuel Fraction Carbon Oxidation FactorA small fraction of a filer s carbon content can escape oxidation and remain as a solid after combustion in the form of ash or soot (for solid fuels) or particulate emissions (fbr natural gas and other gaseous fuels). This unoxidized fraction is a function of several factors, including fuel type, combustion technology, equipment age, and operating practices. This fraction can be assumed to contribute no further to CO2 emissions, so it is easily corrected fbr in estimating CO2 emissions. The stationary combustion CO2 methods in this tool use an "oxidation factor9 to account fbr the unoxidised fraction (where 1.00 = complete oxidation). In general, variability in the oxidation factor is low fbr gaseous and liquid fuels, but can be much larger for solid fuels. For example, an Australian study of coal-fired boilers found that the oxidation factor ranged from 0.99 - 0.88 (IPCC9 2006).The preferred approach for developing a Tier 3 facility-specific oxidation factor is to measure the quantity of residual solid left over from the combustion process and then analyze that residue's carbon content. However, if this is not possible a Tier 1 default value of 1.00 can be assumed.Calculating CO? EmissionsEquation 4Facilities should first ensure that all units are consistent with each other (Appendix III provides unit conversion ratios). Facilities are encouraged to express any Tier 2/3 carbon content data on an energy basis using HHV values, before using Equation 4 to calculate the emissions. Otherwise, when these data are expressed on a mass or volume basis, Equation 5 should be used. Default, Tier 1 values for use with Equations 4 and 5 are given in Appendix I.Calculating CO2 emissions using carbon content data that are expressed on a mass or volume basis44E = Af F F fC,V OX OMass basis:1244Volume basis:E = Af m F()x 一Where:E = Amount of CO2 emitted (metric tons)Av= Volume of fuel consumed (e.g.9 liters, gallons, m3, etc.)A工机=Mass of fuel consumed (e.g.9 kg, short ton, etc.)FCfV = Carbon content of fuel on a volume basis (e.g.9 short tons carbon / gallon)Fc,m = Carbon content of fuel on a mass basis (e.g., short tons carbon / short ton) Fox= Fraction oxidation factor44/12 = The ratio of the molecular weight of carbon to that of CO213Equation 5Calculating CO2 emissions from stationary combustion sources using carbon content data expressed on an energy basis:44 J c, ox 2Where:E = Amount of CO2 emitted (metric tonnes)A = Mass of fuel consumed (e.g.，metric tonnes)HVf= Heating value of fuel (e.g.5 MJ/Kg or thousand Btu/lb)FCth = Carbon content of fuel on a heating value basis (eg, short tons C/million Btu or metric tonnes C/GJ)Fox = Fraction oxidation factor44/12 = The ratio of the molecular weight of carbon to that of CO2CH4 and N2O emissionsThe N2O and CH4 emissions from Electricity Generation and Reheating Furnaces can be calculated using Equation 6. This tool provides two sets of default emission factors that can be used with Equation 6. Appendix II lists fuel-specific default factors that are Tier 1. Table 1 lists equipment-specific factors that are Tier 3. Facilities are encouraged to use the Tier 3 factors whenever possible, although they may instead use the Tier 1 factors if they do not have reliable data on the equipment in use at their combustion units. Tier 2 factors that are fuel- and country-specific, but not equipment-specific, may also be used and may be obtainable from national statistical agencies and other nationallevel organizations. Note that the default N2O factors are generally based on limited measurements and have a high degree of uncertainty.Equation 6Calculating N2O and CH4 emissions from stationary combustion sourcesTier 1: E = AHHVfEF * GWPTier 3: E = Af 田鹏，ESEF * GWPWhere:E = Amount of either N2O or CH4 emitted (metric tonnes CO2-equivalent)Af= Amount of fuel combusted on a mass or volume basis (e.g., lb5 bbl, etc.)EF = Tier 1 fuel-specific emission factor (see Appendix II fbr default values) ESEF = Tier 3 Equipment-specific emission factor (see Table 1 fbr default values) GWP = 21 fbr CH4 or 310 fbr N2O14Table 1: Tier 3 equipment-specific CH4 and N2O default emission factors for stationary combustion sourcesTechnologyLHV/NCV basis: kg/TJ fuelHHV/GCV basis: kg/TJ fuelBasic TechnologyConfigurationch4 n2och4 n2oLiquid fuelsResidual fuel oil/ Shale oil boilers3.0000.3003.1580.316Gas/Diesel oil boilers0.2000.4000.2110.421Large stationary diesel oil engines >600hp (447kW)4.000N/A4.211N/ALiquified Petroleum Gases (LPG) boilers0.9004.0000.9474.211Solid fuelsOther bituminous /Sub- bituminous overfeed stoker boilers1.0000.7001.0530.737Other bituminous /Sub- bituminous underfeed stoker boilers14.0000.70014.7370.737Other bituminous/sub- bituminous pulverisedDry bottom, wall fired0.7000.5000.7370.526Dry bottom, tangentially fired0.7001.4000.7371.474Wet bottom0.9001.4000.9471.474Other bituminous spreader stokers1.0000.7001.0530.737Other bituminous/sub- bituminous fluidised bed combustorCirculating bed1.00061.0001.05364.211Bubbling bed1.00061.0001.05364.211NaturalGasBoilers1.0001.0001.1111.111Gas-fired gas turbines >3MW4.0001.0004.4441.111Natural gas-fired reciprocating engines2-Stroke lean bum693.00 0N/A770.000N/A4-Stroke lean burn597.000N/A663.333N/A4-Stroke rich bum110.00 0N/A122.222N/ABiomassWood/wood waste boilers11.0007.00011.5797.368Source: IPCC 2006, Volume 2, Chapter 2.32.2 Emissions from Coke MakingCO2This guidance provides two methods for calculating the CO2 emissions from coke manufacture. Facilities should chose between the two based on whether or not the coke they consumed was produced onsite. This is because coke manufacture may entail the use of by-products from industrial activities that took place within the site of coke production. Facilities that consume coke produced offsite should not account fbr the emissions from these by-products; otherwise, emissions from these by-products might be double-counted.15The separate consideration of emissions from onsite and offsite coke manufacture also allows the separation of emissions based on ownership. In other words, if coke is purchased from an entity outside the organizational boundaries of the reporting company, the associated emissions are Scope 3, not Scope 1. Likewise, if the coke production facility is offsite, but located within the corporate boundaries of the reporting company, the facility's emissions fall under Scope 1. Figure 3 demonstrates this principle.Figure 3. Diagram illustrating how the accounting of emissions from coke manufacturing facilities depends on whether those facilities exist within the organizational boundaries of the reporting company.wwOffsite coke production facility ownedontrolled by third partyOffsite coke production facility owned/controlled by reporting companyIron & Steel manufacturing plantOnsite coke production facility owned/bontrolled by reporting companyScope 3 emissions: from thirdparty facilitiesScope 1 emissions: from coke manufacturing facilities included within the organizational boundaries of the reporting companyEmissions from onsite and offsite coke production should be estimated using Equations 7 and 8, respectively. Both equations require carbon content data fbr each material input into the coke plant. Companies are encouraged to use facility-specific (Tier 3) values whenever possible. However, if companies do not have the requisite information they may then use the default, Tier 1 values (see Table 2).Equation 7Calculating CO2 emissions firom onsite coke production16F-J CO 2, energy一 CCCcc+E(PMjQ) + BGCbg - a-co q。- COG CCOG-COBh Cb)_b_4412Where:Ecoz, energy = emissions of CO2 from onsite coke production, tonnesCC = quantity of coking coal consumed for coke production in onsite integrated iron and steel production facilities, tonnesPMa = quantity of other process material a, other than those listed as separate terms, such as natural gas and fuel oil, consumed fbr coke and sinter production in onsite coke production and iron and steel production facilities, tonnesBG = quantity of blast furnace gas consumed in coke ovens, m3 (or other unit such as tonnes or GJ.CO = quantity of coke produced onsite at iron and steel production facilities, tonnes COG = quantity of coke oven gas transferred offsite, m3 (or other unit such as tonnes or GJ).COBb = quantity of coke oven by-product b9 transferred offsite to other facilities, tonnesCx = carbon content of material input or output x, tonnes C/(unit for material x) e.g,9 tonnes C/tonneEquation 8Calculating CO2 emissions from offsite coke productionF =CO 2, energy4412CC Ccc + E(PM. eCJ-NIC Cnk a CCOG -E(c。或a) bWhere:ECO7, energy = emissions of CO2 from offsite coke production (tonnes)CC = quantity of coking coal used in non-integrated coke production facilities (tonnes) PMa = quantity of other process material a, other than coking coal, such as natural gas and fuel oil consumed nationally in non-integrated coke production (tonnes)NIC = quantity of coke produced offsite in non-integrated coke production facilities nationally (tonnes)COG = quantity of coke oven gas produced in offsite non-integrated coke production facility (tonnes)COBb= quantity of coke oven by-product b. produced nationally in offsite nonintegrated facilities and transferred offsite to other facilities (tonnes)Cx = carbon content of material input or output tonnes C/(unit fbr material x) e.g., tonnes C/tonneTable 2. Carbon contents fbr materials co