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Version 1.1

July 8, 2005

Calculation Tools for

Estimating

Greenhouse Gas

Emissions

from Pulp and Paper Mills

Version 1.1

July 8, 2005

A Project of

The Climate Change Working Group of

The International Council of Forest and Paper

Associations (ICFPA)

with special contributions from

Paper Manufacturers Association of South Africa

Japan Paper Association

Forest Products Association of Canada

Confederation of European Paper Industries

Chilean Forest and Industry Association

Australian Paper Industry Council

American Forest and Paper Association

Prepared by: National Council for Air and Stream Improvement, Inc. (NCASI)

Research Triangle Park, NC, USA

Questions or comments on this material can be directed to

Brad Upton, NCASI, PO Box 458, Corvallis, OR, USA 97339-0458

phone + 541-752-8801, fax + 541-752-8806, e-mail BUpton@ncasi.org

Version 1.1

July 8, 2005

This page intentionally blank.

Version 1.1

July 8, 2005

CALCULATION TOOLS FOR ESTIMATING GREENHOUSE GAS EMISSIONS

FROM PULP AND PAPER MILLS – Version 1.1

EXECUTIVE SUMMARY

This report contains Version 1.1 of the Calculation Tools for Estimating Greenhouse Gas

Emissions from Pulp and Paper Mills, developed for the International Council of Forests and

Paper Associations by the National Council for Air and Stream Improvement, Inc. (NCASI).

The differences between this version of the tools and Version 1.0, issued in 2001, are

described in Annex G to this report. It is intended that these industry-specific tools be used

in conjunction with a greenhouse gas (GHG) accounting protocol such as the “Greenhouse

Gas Protocol” issued by the World Resources Institute/World Business Council for

Sustainable Development (WRI/WBCSD), the “Climate Leaders Greenhouse Gas Inventory

Protocol Core Module Guidance” issued by the United States Environmental Protection

Agency (USEPA), the “Challenge Registry Guide to Entity and Facility-Based Reporting”

issued by the Voluntary Challenge and Registry (VCR), or other protocol for corporate GHG

inventories.

These tools reflect many of the features of well-known and widely accepted protocols. In

addition, they anticipate a number of questions that pulp and paper mills must address when

preparing facility-level or company-level inventories. A special effort has been made to

ensure that the tools are consistent with guidance issued by the Intergovernmental Panel on

Climate Change (IPCC) and the WRI/WBCSD.

These tools estimate CO2 emissions from fossil fuel combustion based on the carbon content

of the fuel (or a comparable emission factor) and the amount burned. Carbon dioxide

emissions from biomass combustion are not counted as GHG emissions, a convention

common to most of the protocols examined in this review, but if a company elects to do so it

can report them separately. Companies that wish to comply with the WRI/WBCSD GHG

Protocol should include these biomass combustion CO2 emissions, and they should be

reported separately from direct GHG emissions. Regardless of the reporting approach

chosen, it is important to clearly separate estimates of CO2 emissions from fossil fuel

combustion from emissions of CO2 from biomass combustion. Methane and nitrous oxide

emissions from combustion processes, both fossil fuel and biomass, are estimated using fuel-

based emission factors and activity data. Methods are presented for estimating the fossil-

CO2, methane, and nitrous oxide emissions from kraft mill lime kilns and calciners.

Greenhouse gas emissions from landfills and wastewater treatment plants are estimated using

methods derived from those suggested by IPCC, as are emissions from vehicles and other

fossil fuel-fired equipment. In all cases, however, companies may use site-specific

information where it yields more accurate estimates of GHG emissions than the tools

outlined in this report.

Using these tools, indirect emissions related to imports of electricity or steam are included in

the inventory results but are tracked separately from direct emissions. Emissions attributable

to exports of electricity or steam, which are a subset of direct emissions, are explicitly

delineated in order to demonstrate that at some facilities a portion of the direct emissions are

associated with energy streams that are exported to other end users. Emissions from

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Version1.1July8,2005CalculationToolsforEstimatingGreenhouseGasEmissionsfromPulpandPaperMillsVersion1.1July8,2005AProjectofTheClimateChangeWorkingGroupofTheInternationalCouncilofForestandPaperAssociations(ICFPA)withspecialcontributionsfromPaperManufacturersAssociationofSouthAfricaJapanPaperAssociationForestProductsAssociationofCanadaConfederationofEuropeanPaperIndustriesChileanForestandIndustryAssociationAustralianPaperIndustryCouncilAmericanForestandPaperAssociationPreparedby:NationalCouncilforAirandStreamImprovement,Inc.(NCASI)ResearchTrianglePark,NC,USAQuestionsorcommentsonthismaterialcanbedirectedtoBradUpton,NCASI,POBox458,Corvallis,OR,USA97339-0458phone+541-752-8801,fax+541-752-8806,e-mailBUpton@ncasi.orgVersion1.1July8,2005Thispageintentionallyblank.Version1.1July8,2005CALCULATIONTOOLSFORESTIMATINGGREENHOUSEGASEMISSIONSFROMPULPANDPAPERMILLS–Version1.1EXECUTIVESUMMARYThisreportcontainsVersion1.1oftheCalculationToolsforEstimatingGreenhouseGasEmissionsfromPulpandPaperMills,developedfortheInternationalCouncilofForestsandPaperAssociationsbytheNationalCouncilforAirandStreamImprovement,Inc.(NCASI).ThedifferencesbetweenthisversionofthetoolsandVersion1.0,issuedin2001,aredescribedinAnnexGtothisreport.Itisintendedthattheseindustry-specifictoolsbeusedinconjunctionwithagreenhousegas(GHG)accountingprotocolsuchasthe“GreenhouseGasProtocol”issuedbytheWorldResourcesInstitute/WorldBusinessCouncilforSustainableDevelopment(WRI/WBCSD),the“ClimateLeadersGreenhouseGasInventoryProtocolCoreModuleGuidance”issuedbytheUnitedStatesEnvironmentalProtectionAgency(USEPA),the“ChallengeRegistryGuidetoEntityandFacility-BasedReporting”issuedbytheVoluntaryChallengeandRegistry(VCR),orotherprotocolforcorporateGHGinventories.Thesetoolsreflectmanyofthefeaturesofwell-knownandwidelyacceptedprotocols.Inaddition,theyanticipateanumberofquestionsthatpulpandpapermillsmustaddresswhenpreparingfacility-levelorcompany-levelinventories.AspecialefforthasbeenmadetoensurethatthetoolsareconsistentwithguidanceissuedbytheIntergovernmentalPanelonClimateChange(IPCC)andtheWRI/WBCSD.ThesetoolsestimateCO2emissionsfromfossilfuelcombustionbasedonthecarboncontentofthefuel(oracomparableemissionfactor)andtheamountburned.CarbondioxideemissionsfrombiomasscombustionarenotcountedasGHGemissions,aconventioncommontomostoftheprotocolsexaminedinthisreview,butifacompanyelectstodosoitcanreportthemseparately.CompaniesthatwishtocomplywiththeWRI/WBCSDGHGProtocolshouldincludethesebiomasscombustionCO2emissions,andtheyshouldbereportedseparatelyfromdirectGHGemissions.Regardlessofthereportingapproachchosen,itisimportanttoclearlyseparateestimatesofCO2emissionsfromfossilfuelcombustionfromemissionsofCO2frombiomasscombustion.Methaneandnitrousoxideemissionsfromcombustionprocesses,bothfossilfuelandbiomass,areestimatedusingfuel-basedemissionfactorsandactivitydata.Methodsarepresentedforestimatingthefossil-CO2,methane,andnitrousoxideemissionsfromkraftmilllimekilnsandcalciners.GreenhousegasemissionsfromlandfillsandwastewatertreatmentplantsareestimatedusingmethodsderivedfromthosesuggestedbyIPCC,asareemissionsfromvehiclesandotherfossilfuel-firedequipment.Inallcases,however,companiesmayusesite-specificinformationwhereityieldsmoreaccurateestimatesofGHGemissionsthanthetoolsoutlinedinthisreport.Usingthesetools,indirectemissionsrelatedtoimportsofelectricityorsteamareincludedintheinventoryresultsbutaretrackedseparatelyfromdirectemissions.Emissionsattributabletoexportsofelectricityorsteam,whichareasubsetofdirectemissions,areexplicitlydelineatedinordertodemonstratethatatsomefacilitiesaportionofthedirectemissionsareassociatedwithenergystreamsthatareexportedtootherendusers.EmissionsfromVersion1.1July8,2005combinedheatandpower(CHP)plantsareallocatedusingtheWRI/WBCSD“efficiencymethod.”Thecalculationtoolsallowcompaniestodevelopcorporateinventoriesthatincludealldirectemissionsourcesfromwithintheorganizationalboundaries–e.g.,company-ownedtruckfleets–aswellasindirectemissionsourcesoutsidetheorganizationalboundaries–e.g.,emissionsfromelectricity,heat,andsteampurchasedandconsumed–andon-sitepulpandpapermakingoperationsoutsidetheorganizationalboundaries.Itisunderstood,however,thatcompanieswillincludeindirectemissionsourcesthatarebestsuitedtotheobjectivesoftheinventory.Formostmills,theGHGprofilewillbedominatedbystationaryfossilfuelcombustionemissionsandemissionsattributabletopurchasesofpowerandsteam,emissionsthatarediscussedinSections8and12.ForinventorieswhichconsiderCO2emissionsonly(i.e.,CH4andN2Oemissionsarenotincludedintheemissionsinventory),itmaybeappropriatetoestimateemissionsbasedsolelyonfacility-levelfuelconsumptionactivitydataandCO2emissionfactors.Incertainsituations,CH4andN2Oemissionsmaybeestimatedadequatelyusingfacility-levelactivitydataaswell.Toaidininterpretingtheresultsoftheinventory,thesetoolsrecommendthattheresultsincludeadescriptionoftheoperationalboundariesoftheinventoryandalistofemissionfactorsusedtoestimateemissions.Theformatsuggestedforpresentingtheresultsoftheinventoryallowsacompanytoreportdirectemissions(thosefromsourcesownedorcontrolledbythecompany)separatelyfromindirectemissions(thosethatareaconsequenceoftheactivitiesofthecompany,butoccurfromsourcesownedorcontrolledbyanothercompany).Thecompanyisfreetoselectamethodfordeterminingtheownershipofemissions,butthemethodshouldbeexplainedintheinventoryresults.TheuserisdirectedtotheWRI/WBCSDGHGProtocolforguidanceonhowtodetermineownershipofemissionsfrompartly-ownedorpartly-controlledsources.AnExcel®workbookisavailabletoassistinperformingthecalculationsdescribedinthisreport.Version1.1July8,2005CONTENTS1.0INTRODUCTION............................................................................................................12.0FORESTPRODUCTSINDUSTRYGREENHOUSEGASEMISSIONSINPERSPECTIVE.................................................................................................................23.0RELATIONSHIPOFTHESECALCULATIONTOOLSTOOTHERGREENHOUSEGASPROTOCOLS...............................................................................24.0OVERVIEWOFTHECALCULATIONTOOLS...........................................................44.1StepsInvolvedinApplyingtheCalculationTools..................................................44.2DataQuality.............................................................................................................64.3Units.........................................................................................................................75.0DETERMININGTHEORGANIZATIONALBOUNDARIESOFTHEINVENTORY...................................................................................................................96.0IDENTIFYINGPULPANDPAPEROPERATIONSTOBEINCLUDEDWITHINTHEINVENTORY.........................................................................................107.0MATERIALITYANDINSIGNIFICANTEMISSIONS...............................................118.0GREENHOUSEGASEMISSIONSFROMSTATIONARYFOSSILFUELCOMBUSTION..............................................................................................................148.1CarbonDioxide......................................................................................................148.2MethaneandNitrousOxide...................................................................................169.0EMISSIONSFROMKRAFTMILLLIMEKILNSANDCALCINERS......................2210.0CARBONDIOXIDEEMISSIONSFROMMAKE-UPCHEMICALS........................2510.1EmissionsfromMake-upCarbonatesUsedinthePulpMill................................2510.2EmissionsfromLimestoneorDolomiteUsedinFlueGasDesulfurization(FGD)Systems.......................................................................................................2611.0EMISSIONSFROMSTATIONARYCOMBUSTIONOFBIOMASSFUELS...........2711.1ReleasesofBiomass-DerivedCarbonDioxidefromBurningBiomassFuels......2711.2MethaneandNitrousOxideEmissionsfromBurningBiomassFuels..................28Version1.1July8,200512.0EMISSIONSATTRIBUTABLETOIMPORTSANDEXPORTSOFELECTRICITYANDSTEAM.......................................................................................3012.1EmissionFactorsforPurchasedPowerandSteam................................................3112.2ElectricityImports.................................................................................................3112.3ElectricityExports.................................................................................................3212.4SteamImports........................................................................................................3312.5SteamandHotWaterExports................................................................................3312.6AllocatingEmissionsfromCombinedHeatandPower(CHP)Systems..............3313.0GREENHOUSEGASEMISSIONSFROMVEHICLESANDMISCELLANEOUSFOSSILFUEL-FIREDEQUIPMENT.........................................3713.1GreenhouseGasEmissionsfromOn-RoadVehicles............................................3713.2GreenhouseGasEmissionsfromOff-RoadVehiclesandEquipment..................3714.0GREENHOUSEGASEMISSIONSFROMWASTEINLANDFILLS........................3914.1UsingDatafromLandfillGasCollectionSystems................................................4014.2EstimatingMethaneEmissionsatLandfillswithoutGasCollectionData............4115.0GREENHOUSEGASEMISSIONSFROMANAEROBICTREATMENTOFWASTEWATERORSLUDGE.....................................................................................4515.1AnaerobicTreatmentOperationswhereOff-GasesareCaptured.........................4515.2AnaerobicTreatmentOperationswhereOff-GasesareReleasedtotheAtmosphere............................................................................................................4516.0PRESENTINGTHERESULTSOFTHEINVENTORY..............................................46REFERENCES........................................................................................................................57Version1.1July8,2005ANNEXESAGREENHOUSEGASEMISSIONSFROMKRAFTMILLLIMEKILNSANDCALCINERS.................................................................................................................A1BALLOCATINGGREENHOUSEGASEMISSIONSFROMCOMBINEDHEATANDPOWER(CHP)SYSTEMS:RECOMMENDEDGUIDANCEANDREVIEWOFMETHODS..............................................................................................B1CGREENHOUSEGASESFROMVEHICULARTRAFFICANDMACHINERY:OVERVIEWOFMETHODSINEXISTINGPROTOCOLS.......................................C1DGREENHOUSEGASESFROMWASTEMANAGEMENTATPULPANDPAPERMILLS:RECOMMENDEDAPPROACHANDREVIEWOFEXISTINGMETHODS.................................................................................................D1ECARBONDIOXIDEFROMBIOMASSCOMBUSTION...........................................E1FTABLESOFGREENHOUSEGASEMISSIONFACTORS.......................................F1GSUMMARYOFSIGNIFICANTREVISIONSTOVERSION1.0..............................G1HREFERENCESFORANNEXESATHROUGHG......................................................H1Version1.1July8,2005TABLESTable1.EmissionFactorRangesUsefulinIdentifyingSignificantandInsignificantSourcesofGHGs...................................................................................................13Table2.IPCCDefaultCO2EmissionFactorsforFossilFuels...........................................15Table3.RecommendedCorrectionFactorsforUnoxidizedCarbonfromVariousGuidanceDocuments.............................................................................................15Table4.IPCCTier1CH4andN2OEmissionFactorsforStationaryCombustion.............18Table5.IPCCTier2UncontrolledCH4andN2OEmissionFactorsforIndustrialBoilers....................................................................................................................18Table6.EmissionFactorsforKraftMillLimeKilnsandCalciners...................................24Table7.EmissionsfromCalciumCarbonateandSodiumCarbonateMake-upinthePulpMill................................................................................................................25Table8.EmissionFactorsforCH4andN2OfromBiomassCombustion...........................29Table9.EmissionFactorsforNon-RoadMobileSourcesandMachinery.........................38Table10.RecommendedDefaultValuesforkandL0forEstimatingLandfillMethaneEmissions...............................................................................................................42Table11.ExampleofaTabletoReportOperationalBoundariesoftheInventory..............48Table12.ExampleofaTabletoReportGHGInventoryResults–DirectEmissions..........49Table13.ExampleofaTabletoReportGHGInventoryResults–IndirectEmissions.......50Table14.ExampleofaTabletoReportEmissionFactorsUsedtoPreparetheInventory................................................................................................................51Table15.ExampleGHGInventoryResults–OperationalBoundariesoftheInventory.....52Table16.ExampleGHGInventoryResults–DirectEmissions...........................................54Table17.ExampleGHGInventoryResults–IndirectEmissions........................................55Table18.ExampleGHGInventoryResults–EmissionFactorsUsedtoPreparetheInventory................................................................................................................56FIGURESFigure1.SchematicforExampleInventoryResults.............................................................53Version1.11July8,2005CALCULATIONTOOLSFORESTIMATINGGREENHOUSEGASEMISSIONSFROMPULPANDPAPERMILLS–Version1.11.0INTRODUCTIONRespondingtotheneedforimprovedmethodsforestimatinggreenhousegas(GHG)emissionsfrompulpandpapermills,in2001theInternationalCouncilofForestandPaperAssociations(ICFPA)agreedtodevelopinternationaltoolsto:•enableharmonizedcollectionofcredible,transparent,andcomparabledataworldwide•addresstheforestproductsindustry’suniqueattributes•establishaframeworkthatwillassistinimplementingavarietyofprogramsthatmightmakeuseofcarboninventorydataToaccomplishthis,theICFPAClimateChangeWorkingGroupretainedtheresearchinstituteNationalCouncilforAirandStreamImprovement,Inc.(NCASI)toreviewexistingGHGprotocolsandassisttheindustryindevelopingcalculationtoolsforestimatingGHGemissions.Theresultsofthateffortarecontainedinthisreport.Version1.0oftheseCalculationToolswasissuedinDecember2001.AnnexGpresentsanoverviewoftherevisionsmadeinthepreparationofthisversionoftheCalculationTools.Thecalculationtoolsaredescribedinthebodyofthereport.TheAnnexessummarizerelevantfeaturesofthecalculationmethodsusedinanumberofexistingGHGprotocolsandprovideadditionaldetailsonestimationmethods.Thismaterialencompassesonlymanufacturing-relatedemissionsfrompulpandpaperproduction.Issuesrelatedtocarbonsinksorforestsequestrationarenotaddressed.1ThesecalculationtoolswillassistcompaniesinpreparingGHGemissioninventoriesforanumberofpurposes,includinginternalcompanybenchmarking,publicreporting,productprofiles,andcarbontrading.TherulesgoverningthedevelopmentofaGHGinventory,however,canvarysubstantiallyfromoneprogramtoanother,sotheuserofthesetoolsshouldalwaysbefamiliarwiththerequirementsimposedbytheintendeduseoftheinventoryresults.Theseindustry-specifictoolsshouldbeusedinconjunctionwithanacceptedGHGaccountingprotocolsuchasthe“GreenhouseGasProtocol”issuedbytheWorldResourcesInstitute/WorldBusinessCouncilforSustainableDevelopment(WRI/WBCSD),the“ClimateLeadersGreenhouseGasInventoryProtocolCoreModuleGuidance”issuedbytheUnitedStatesEnvironmentalProtectionAgency(USEPA),the“ChallengeRegistryGuidetoEntityandFacility-BasedReporting”issuedbytheVoluntaryChallengeandRegistry(VCR),orotherprotocolsforcorporateGHGinventories.ThoseprotocolsprovidevaluableinformationonissuesrangingfromdefiningtheobjectivesforaGHGinventorytooptions1IPCChasdevelopedmethodsthatcountriesareusingtocharacterizesequestration(IPCC1997a,b,c,2000b,2003),andagreatdealofworkisunderwaytoimprovetheunderstandingofsequestrationanditsmeasurement.SomeofthesestudiesaresummarizedbySkogandNicholson1998;Appsetal.1999;Matthews1996;andBirdsey1996.2Version1.1July8,2005forverifyingtheresults–issuesbeyondthescopeoftheindustry-specificcalculationtoolsinthisreport.Georgia-PacificCorporation’sprotocolisanexampleofhowonecompanydevelopedaprotocolspecifictotheforestproductsindustry(GP2002).2.0FORESTPRODUCTSINDUSTRYGREENHOUSEGASEMISSIONSINPERSPECTIVETheforestproductsindustryhasanimportantandcomplexroleintheglobalcarboncycle.Forestssupplytheindustry’sprimaryrawmaterial.Thesustainablemanagementoftheseforestssequestersmassiveamountsofcarbonandprovidesneededproductsthatcontributetosignificantcarbonpoolsduringtheiruseandafterbeingdiscarded.Inaddition,forestsprovidemultipleenvironmental,societal,andeconomicbenefits.Effortstoexpandtheamountofforestedlandareincreasingcarbonstorageinmostofthedevelopedworldandnewplantationsarebeingestablishedinmanyareasofthedevelopingworld.Researchisongoingtoidentifyforestmanagementpracticescapableofoptimizingcarbonstorageinexistingforestswhilemaintainingorenhancingforestproductivityandprotectingtheenvironment.Carbonisalsostoredwhenforestsaremanagedtoproduceneededproductsbecausemanyoftheseproductsstorecarbonforextendedperiodsoftimeastheyareusedandafterdisposal.Recyclingisanimportantpartofthecarboncyclebecauseitcanhelpextendthetimeduringwhichcarbonisstoredinproducts.Ithasbeenestimatedthattheamountofcarbonstoredinforestproductsisincreasingby139millionmetrictonsofcarbonperyearonaglobalbasis(Winjum,Brown,andSchlamadinger1998).Theforestproductsindustryreliesheavilyonbiomassfuelsthatdisplacefossilfuels,theprimarycontributortorisingatmosphericlevelsofcarbondioxide.Inanumberofcountries,morethanhalftheindustry’senergyrequirementsaremetusingbiomassfuels.Forestproductsthatcannotbeeconomicallyrecycledprovideonesourceofbiomassfuels.Thepulpandpaperindustryisoneofthegloballeadersintheuseofcombinedheatandpower(CHP)systems,alsocalledcogenerationsystems.CHPsystemsproduceelectricalpowerandthermalenergyfromthesamefuel,yieldingtwiceasmuchormoreusableenergyfromthefuelasnormalmethodsforgeneratingpowerandsteam.ThisreducesGHGemissionsbyreducingthedemandforfossilfuels.ThepulpandpaperindustriesinsomecountriesderivemorethanhalftheirenergyfromCHPsystems.Theindustry’sinteractionswiththeglobalcarboncycleareextensiveandcomplex.Itisimportant,therefore,thattheindustry’sGHGemissionsnotbeviewedinisolation.Itisonlywithinthecontextoftheoverallforestproductscarboncyclethatthesignificanceoftheindustry’semissionscanbeproperlyevaluated.3.0RELATIONSHIPOFTHESECALCULATIONTOOLSTOOTHERGREENHOUSEGASPROTOCOLSTherearemanyprotocolsforestimatingandreportingGHGemissions.MostoftheexistingprotocolsarebasedonacommonsetofgeneralprincipleswithdifferencesprimarilyVersion1.13July8,2005attributabletothedifferingpurposesoftheprotocols(e.g.,nationalinventories,corporateinventories,etc.).ThegeneralprinciplesforGHGinventorydevelopmentareimportantandshouldbeaddressedinpreparinganyinventoryofGHGemissions.Thisreport,however,devotesrelativelylittleattentiontosuchissuesbecausetheprinciplesaregenericandinformationisavailableinavarietyofotherplaces.Someespeciallyhelpfulsourcesofgeneralinformationoninventorypreparationare:•theIntergovernmentalPanelonClimateChange(IPCC)(IPCC1997a,b,c,2000a)•theWorldResourcesInstitute/WorldBusinessCouncilforSustainableDevelopment(WRI/WBCSD)(WRI2001,2004a)•thePEWCenteronGlobalClimateChange(Loreti,Wescott,andIsenberg2000;Loreti,Foster,andObbagy2001)•theUnitedStatesEnvironmentalProtectionAgency(USEPA2003)•Canada’sClimateChangeVoluntaryChallengeandRegistry(VCR2004)TheWRI/WBCSDandPEWCenterdocumentsareespeciallyrelevantforcompaniesusingthesecalculationtoolsbecausetheyfocusoncompany-levelreporting.Instructionsonhowtoobtainthesedocumentsareincludedintheliteraturecitations.TheWRI/WBCSDandPEWCenterdocumentsprovidehelpfulinformationonthesegeneric,butimportant,issues:•GHGaccountingandreportingprinciples(e.g.,relevance,completeness,consistency,transparency,accuracy)•definingcorporateobjectivesforinventories(e.g.,publicreporting,voluntaryinitiatives,carbontrading)•establishingorganizationalandoperationalboundaries•establishinghistoricalreferencedataandtrackingemissionsovertime•managinginventoryquality•verificationThepulpandpaperindustrycalculationtoolsinthisreportareintendedtoassistcompaniesindevelopingdatathatcanbeusedtofulfilltherequirementsofanumberofprotocols,includingtheWRI/WBCSDGHGProtocol.GiventhewidespreadacceptanceoftheWRI/WBCSDGHGProtocol,itisimportanttonotethatthereisoneareawherethesecalculationtoolsmayyieldinformationthatisnotcompletelysufficientforreportingundertheWRI/WBCSDGHGProtocol.Specifically,theGHGProtocolsuggeststhatcompaniesreportemissionsofhydrofluorocarbons(HFCs)fromairconditioningandrefrigeration,butHFCemissionsarenotaddressedinthesepulpandpapermillcalculationtools.WRI/WBCSDhasacalculationtoolforestimatingHFCandPFCemissions(ToolforCalculatingHFCandPFCEmissionsfromtheManufacturing,Installation,OperationandDisposalofRefrigerationandAir-conditioningEquipment,Version1.0),availablefordownloadfromtheGHGProtocolwebsite(www.ghgprotocol.org).TheIPCChasalsoissuedguidancethatcompanieswantingtoestimatetheseemissionsmightfindhelpful(IPCC1997c,Section2.17.4.2).4Version1.1July8,2005ThereareotherdifferencesbetweentheWRI/WBCSDGHGProtocolandthecalculationtoolspresentedhere,butthedifferencesresultinthesetoolsprovidingadditionalinformationnotrequiredbytheGHGProtocolorprovidingitinaslightlydifferentformat.PerhapstheonlysignificantvariancefromIPCC’srecommendedapproachesisintheareaoflandfillemissions.IPCC’sapproachreliesongenericestimationmethods,whilethesetoolssuggestthatsite-specificlandfillgascollectiondatacanoftenbeusedasthebasisfortheestimateswherethesedataareavailable.4.0OVERVIEWOFTHECALCULATIONTOOLS4.1StepsInvolvedinApplyingtheCalculationToolsIngeneralterms,thecalculationtoolsinvolvetheuserperformingthefollowingsteps,mostofwhicharedescribedindetailinlatersectionsofthisreport.4.1.1DeterminingtheObjectivesoftheInventoryMostprotocolsfordevelopingcorporateGHGinventories,includingtheWRI/WBCSDGHGProtocol,canhelpcompaniesunderstandthevarietyofusesforGHGinventoryresults(WRI2001,2004a).Thewaytheinventoryisdesignedandconductedwilldependlargelyontheintendedusesoftheresults.BeforeundertakingaGHGinventory,therefore,companiesshouldassurethemselvesthatthemethodsusedtodeveloptheinventorymeettherequirementsimposedbyitsobjectives.4.1.2IdentifyingBoundaryConditionsTherearetwotypesofboundariesthatmustbeconsideredinaGHGinventory–operationalboundariesandorganizationalboundaries.Theorganizationalboundariesreflecttheownershiporcontrolofthecompany’soperationsandlegalstructure.TheGHGProtocol(WRI2004a)providesextensiveguidanceregardingdeterminationoforganizationalboundaries.Itdescribestheprocessofsettingorganizationalboundariesas“select[ing]anapproachforconsolidatingGHGemissionsandthenconsistentlyapply[ing]theselectedapproachtodefinethosebusinessesandoperationsthatconstitutethecompanyforthepurposeofaccountingandreportingGHGemissions.”TheGHGProtocolrecommendsthateitheroftwoapproachesbeusedtoconsolidateGHGemissionsinsettingorganizationalboundaries:theequityshareandthecontrolapproaches.Anextensivediscussionofdeterminingorganizationalboundaries,includingexamples,isprovidedintheGHGProtocol(WRI2004a).Theoperationalboundariesdefinetheemissionsourcesthatneedtobeincludedinordertosatisfytheobjectivesoftheinventory,categorizetheminto“direct”and“indirect”emissions,anddeterminethescopeofaccountingandreportingforindirectemissions.Directandindirectemissionsaredefinedasfollows(WRI2001,2004a):•Directemissionsare“emissionsfromsourcesthatareownedorcontrolledbythe[reporting]company.”•Indirectemissionsare“emissionsthatareaconsequenceoftheactivitiesofthe[reporting]companybutoccuratsourcesownedorcontrolledbyanothercompany.”Version1.15July8,2005Ofcourse,thereisanalmostendlesschainofupstreamanddownstream“consequences”that,atleasttheoretically,canbeconnectedtoacompany’sactivities.GHGprotocols,however,usuallyrequireonlyalimitedsetofindirectemissions–thoseassociatedwithelectricalpower,steam,andheatconsumedbythecompanybutproducedbyanotherentity–andthesearetheindirectemissionsaddressedinthesecalculationtools.Thetoolshavebeendevelopedtoaddress:•directemissionsfromon-siteoperations(e.g.,company-ownedpowerboilers)•directemissionsfromoff-siteoperations(e.g.,company-ownedharvestingequipment)•theportionofdirectemissionsattributabletoexportedpowerorsteam•indirectemissionsrelatedtoimportsofpowerorsteam(includingthosefromoutsourcedpowerislands)•indirectemissionsfromon-siteoperationsnotinvolvingpowerandsteamtransfers(e.g.,outsourcedbuton-sitewastewatertreatmentoperations)CompaniespreparingreportsmeetingtherequirementsoftheGHGProtocolneedtoincludealldirectemissionsaswellasthoseindirectemissionsattributabletoimportedelectricity,steam,andheatedorcooledwater(WRI2004a).Emissionsfromoperationsthatarenotpartofthenormalpulpandpapermakingprocessarenotincludedwithinthescopeofthesetools,althoughcompaniesmaysometimesneedtoincludethemtosatisfytheobjectivesoftheinventory(e.g.,iftheyarewithintheorganizationalboundariesofthecompany).4.1.3EstimatingEmissionsThenextstepisestimatingtheGHGemissions.Thecalculationtoolsinthisreportaddress:•CO2emissionsfromstationaryfossilfuelcombustion•CH4andN2Oemissionsfromfossilfuel-firedunits,recoveryfurnaces,biomass-firedboilers,andlimekilns•CO2emissionsfrommake-upCaCO3orNa2CO3usedinthepulpmill•CO2,CH4,andN2Oemissionsfromtransportationandmobilesources•CH4emissionsattributabletomillwastesinlandfillsandanaerobicwastetreatmentoperations•emissionsfrommobilesources(e.g.,company-ownedharvestingequipmentandcompany-ownedtruckfleets)•fossilfuel-derivedCO2exportedtosatelliteprecipitatedcalciumcarbonate(PCC)plants•importsofCO2(e.g.,forpHneutralization)•GHGemissionsassociatedwithpowerandsteamthatisimportedandconsumed•GHGemissionsattributabletopowerandsteamexportsThesetoolsforestimatingGHGemissionsfrompulpandpapermillsallowcompaniestoestimateCO2releasesderivedfrombiomass,butthiscarbonisnotincludedinGHGemissiontotals(i.e.,itistrackedseparately).Biomasscarbonisconsidered“carbonneutral”becausethecarboninbiomassoriginatesintheatmosphere.Theburningofbiomassrecyclescarbontotheatmosphere,unliketheburningoffossilfuels,whichaddsnewcarbon6Version1.1July8,2005totheatmosphere.TheGHGProtocolfollowsareportingconventionthatisconsistentwiththatusedinnationalinventories,whereinCO2emissionsfromthecombustionofbiomassareincludedforinformationalpurposesbutarenotincludedinnationalemissiontotals.Methodsforestimatingreleasesofbiomass-derivedCO2arecontainedinAnnexE.Althoughnotaddressedinthesecalculationtools,fuelgassystempipingmayhavemethaneequipmentleaks(e.g.,pipingassociatedwithanaturalgasboiler).Whereuserswishtoaddresssuchfugitiveemissions,whichwouldprobablybesmallinrelationtotheGHGemissionscategorieslistedabove,moreinformationcanbeobtainedintheUSEPApublicationProtocolforEquipmentLeakEmissionEstimates(USEPA1995).4.1.4PresentingResultsThecalculationtoolsemphasizethedisaggregatedandtransparentpresentationofresults.InSection16ofthisreportanexampleformatforreportinginventoryresultsprovidesthecompanyanopportunitytoconveytransparentanddisaggregatedinformation(however,thecompanymaychoosetoreportusingadifferentformat).AnnexEprovidesanexampleformatforreportingadditionalinformationonemissionsofbiomass-derivedCO2.4.2DataQualityThecalculationtoolsdescribedinthisreportcanbeusedtodevelopestimatesforanumberofpurposes.Toalargeextent,thepurposeoftheinventorywilldictatethequalityofthedatathatareneededandtheapproachusedtodeveloptheinventory.Indevelopingcorporatebenchmarkingdata,forinstance,itmightbeacceptabletouseagenericemissionfactorforcoalburning,butacarbontradingprogrammightrequirethatemissionestimatesbebasedonthecarboncontentofthespecificcoalbeingburned.Thedataqualityrequirementsimposedbytheintendeduseoftheinventoryshouldbedefinedbeforethecompanybeginstheinventory.Formostpurposes,itisacceptableforcompaniestoestimateGHGemissionsusingemissionfactorsandcorresponding“activitydata”(e.g.,amountoffuelconsumed).Formostmills,thelargestsourcesofGHGemissionsarefossilfuel-firedstationarycombustionunits.Fortunately,inmostcasestheseemissionscanbeaccuratelyestimatedbecausefacilitiesusuallyhaveexcellentrecordsofthetypesandamountsoffossilfuelbeingconsumed,andCO2emissionsfromthesesourcesaredirectlyrelatedtofuelcarboncontentasreflectedinwidelyacceptedemissionfactors.Formostothersources,however,thequalityofGHGemissionestimatesismuchlower,sometimesbecauseofinadequateactivitydata,butmoreoftenduetoemissionfactorsthatarebasedonveryfewdata.BecauseoftheimportanceofemissionfactorstotheresultsofaGHGinventory,thesecalculationtoolsincludeatable(Table14)thatcompaniesareencouragedtousetoshowtheemissionfactorsusedtodeveloptheinventory.Itcanbeexpectedthatmanymoreemissionmeasurementswillbemadeincomingyearsandimprovedemissionfactorswillbedevelopedreflectingthesenewdata.UsersofemissionsinventorydataneedtounderstandthisprocessandtheresultingimpactitwillhaveonGHGinventoryresults.Onecanbecertainthatthequalityoftheestimateswillimproveovertime,Version1.17July8,2005butitisimpossibletoforecastwhethertheestimateswillbeadjustedupwardordownwardintheprocess.ThechangesareexpectedtoberelativelyunimportanttotheGHGprofileofmostmills,however,becausethelargestsourcesofGHGsfrommostpulpandpapermills,stationaryfossilfuelcombustionunits,arewellunderstood.4.3UnitsDifferentcountriesusedifferentunitsofmeasure(e.g.,shorttonsversusmetrictonnes,USgallonsversusUKgallons).Thiscancreateconsiderableconfusionwhenemissionfactorsandestimationtechniquesareappliedinternationally.TheSI(metric)systemisusedthroughoutthisreport.Annexescontainemissionfactorsandotherparametersintheunitspreferredbytheauthorityorcountryresponsiblefortheinformation.Someoftheimportantissuesrelatedtounitsofmeasurementarehighlightedhere.4.3.1UnitsofMeasureforGreenhouseGasesGreenhousegasesareoftencomparedonthebasisoftheirestimatedpotentialtocauseglobalwarming.FactorscalledGlobalWarmingPotentials(GWPs)havebeendeveloped,andcanbeusedtoconvertaquantityofnon-CO2greenhousegasintoanamountofCO2withanequivalentwarmingpotential.Althoughthederivationofthesefactorsinvolvesalargenumberofassumptions,GWPsarealmostuniversallyusedtocompareonegreenhousegastoanother.TheGWPforCH4is21so,fromthestandpointofpotentialglobalwarming,everygramofCH4isequivalentto21gramsofCO2.TheGWPforN2Ois310.2Thederivationofthesefactorsisexplainedelsewhere(IPCC1996).WhenanemissionestimateisthesumofseveralGHGsexpressedastheequivalentamountofCO2,theestimateissaidtobeinCO2-equivalents,sometimesabbreviatedasCO2e,CO2eq,orCO2-equiv.ToconvertCO2,CH4,andN2OemissionsintoCO2-equivalents,multiplyCH4emissionsby21andN2Oemissionsby310,thenaddbothtothecorrespondingCO2emissions.CO2-equivalentsarealsosometimesreportedastheweightofthecarbonintheCO2-equivalents,usuallyreportedinmetrictonnesofcarbonequivalents(MTCEs).MTCEsarecalculatedbymultiplyingtheweight(intonnes,equalto1000kg)ofCO2-equivalentsby12/44,theweightfractionofcarbonincarbondioxide.Forpurposesoftransparencyandtoavoidconfusion,inthesecalculationtoolsgreenhousegasquantitiesareusuallyreportedintermsofthemassoftheindividualGHG,ratherthanCO2-equivalentsorMTCEs.Insomecases,however,companiesmayfindthatitisappropriatetouseemissionfactorsthatarebasedonthecombinedemissionsofseveralGHGsexpressedintermsofCO2-equivalentsorMTCEs.Thisisacceptableprovideditismadeclearintheresults.2RecentresearchsummarizedinIPCC2001suggeststhattheGWPforCH4shouldbehigher(23)andthatforN2Oshouldbelower(296)thanthevaluespreviouslyrecommendedbyIPCC(1996).However,therevisedGWPshavenotbeenwidelyadoptedatthistime.Therefore,thisreportusestheGWPvaluesrecommendedbyIPCC(1996)(21forCH4and310forN2O).8Version1.1July8,20054.3.2HeatContentofFuels–GCVvs.NCVSomecountriesmeasurefuelaccordingtoitsgrosscalorificvalue(GCV)orhigherheatingvalue(HHV),whileothercountriesusenetcalorificvalue(NCV)orlowerheatingvalue(LHV).ThedistinctionbetweenGCVandNCVarisesfromthedifferentphysicalstates(liquidorgaseous)watermaybeinfollowingcombustion.TheGCVincludesthelatentenergyofcondensationofwaterfollowingcombustion.TheNCViscomputedforproductwaterinthegaseousstate(i.e.,notcondensed).ThelatentenergyofvaporizationofwaterisdeductedfromtheGCV.Whenamoistfueliscombusted,twosourcesofproductwaterexist–themoisturepresentinthefuelandthewaterformedfromthehydrogeninthefuelduringcombustion.TheNCVofafuelatanymoisturecontentcanbedeterminedas(KitanaandHall1989,p.883):)]9()[1(HMGCVMNCVdrysolidswet+−−=λ(Eq.1)where:NCV=netcalorificvalueatanymoisturecontentGCVsolids=grosscalorificvalueofdryfuel(zeromoisturecontent)λ=latentheatofvaporizationofwater(2.31MJ/kgat25°C)Mwet=moisturecontentoffuelonawetbasis(expressedasafraction)Mdry=moisturecontentoffuelonadrybasis(expressedasafraction)H=massfractionofhydrogenindryfuel(expressedasafraction)IftheNCVistobeexpressedintermsofdryfuel(e.g.,correspondingtothedrysolidsinthefuel)itcanbedeterminedfromtheGCVofthedryfuel(GCVsolids):HGCVNCVsolidssolidsλ9−=(Eq.2)where:NCVsolids=netcalorificvalueofdryfuel(zeromoisturecontent)AcommonlyacceptedapproximationisthatNCVis95%ofGCVforcoalandoiland90%ofGCVfornaturalgas(IPCC1997c).IPCCdoesnotprovidearelationshipbetweenNCVandGCVforbiomassfuels,presumablybecausethemoisturecontentofbiomassfuelscanvaryextensively.However,inmostinstancestheforestproductsindustrycharacterizestheenergycontentofbiomassfuels(e.g.,spentpulpingliquors,hoggedfuels,etc.)intermsoftheenergyinthedrysolidsofthebiomass.Therefore,Equation2canbeusedtodeveloparelationshipbetweenNCGandGCVforbiomassfuelsonadrybasis.Ahydrogencontentvaluerepresentativeofmanywoodspeciesisapproximately6%(basedondrywood,expressedasthefraction0.06)(Browning1975,TableVI,p.74).AtypicalNCVsolidsvalueforwoodis20MJ/kg(IPCC1997c).Therefore:(0.06)water)MJ/kg31.2(9drywoodMJ/kg20××−==solidssolidsGCVNCV∴drywoodMJ/kg25.21(0.06)water)MJ/kg31.2(9drywoodMJ/kg20=××+=solidsGCV(Eq.3)Version1.19July8,2005AnapproximaterelationshipbetweenNCVsolidsandGCVsolidscanbedevelopedusingthisresult:95.094.025.2120≅==∴solidssolidsGCVNCV(Eq.4)Itisimportanttorealizethattherelationaboveisonlyvalidwhentheenergycontent(intermsofbothGCVandNCV)areexpressedintermsofthedryfuel(i.e.,energyexpressedintermsofbiomasssolids,suchas20GJNCVpertonnedrywood).Inthisreport,NCV(LHV)isused.Insomecases,theemissionfactorshavebeenconvertedfromGCV(HHV)unitsaslistedinthesourcesforthefactors,usingtheapproximationsdescribedabove.IntheAnnexes,energy-relatedparametersareexpressedintheunitsusedbytheauthoritiesorcountriesthatdevelopedtheinformation.Exceptwherenoted,theAnnexesuseNCV(LHV).5.0DETERMININGTHEORGANIZATIONALBOUNDARIESOFTHEINVENTORYOrganizationalboundariesdefinethecompanyforthepurposeofaccountingforGHGemissions.Therearealargenumberofpossibleownershiparrangements,makingitdifficulttoprovidespecificinstructionsonhowtoderiveorganizationalboundaries.PerhapsthemostthoroughdiscussionofmethodsfordeterminingorganizationalboundariesiscontainedintheWRI/WBCSDGHGProtocol(WRI2004a).Companieswhoseorganizationalboundariesincludepartially-ownedorpartially-controlledsourceswillwanttoobtainthatdocument.TheapproachoutlinedintheGHGProtocolissummarizedherein.WheretheallocationofGHGsisspecifiedcontractually,thatallocationistobeused.OtherwisetheWRI/WBCSDGHGProtocolsuggeststhatallocationbedoneinoneoftwoways:accordingtocontroloraccordingtoequityshare.Ofcourse,ifthereportingcompanyownsalloftheoperationsconsideredintheinventorytheorganizationalboundarieswillbethesamewhendeterminedbyeitherapproach.TheGHGProtocolalsooutlinesdifferentselectioncriteriathatwillfacilitatethechoiceofapproach,includingtheconsistencywithfinancialaccounting(WRI2004a).Aftertheorganizationalboundariesofthecompanyhavebeendetermined,operationalboundariesthencategorizedirectandindirectemissions,usingtheapproachchosenunderorganizationalboundaries(eitherownershiporcontrol).Thesituationisusuallystraightforwardfortheconsumptionofpurchasedelectricityorsteam,becausetheemissionsareusuallyfromsourcesoutsidethecompany’sownershipandcontrolandare,therefore,indirect.Companiesusingthesecalculationtoolsmayencountersituationswheretheinventoryincludesemissionsourcesfromwhichonlyaportionoftheemissionswillbereported(or“consolidated”)asdirectemissionsatthecorporatelevel,astheyarefromoperationsorcompaniesjointlyownedorcontrolled.Inothercases(e.g.,outsourcedoperationsthatare10Version1.1July8,2005notownedorcontrolled)emissionsmightbereportedfullyasindirect.Someexamplesinclude:•combinedheatandpoweroperationswherethemillisapartialownerofthegeneratingfacilities•powerislandsthatareowned,atleastinpart,byothercorporateentities•wastewatertreatmentorlandfilloperationsownedoroperatedbythirdparties•millswheremultiplepartiesshareownershipofthefacility6.0IDENTIFYINGPULPANDPAPEROPERATIONSTOBEINCLUDEDWITHINTHEINVENTORYAtableisincludedinthisreport(Table11)whichcanbeusedtodocumenttheoperationsincludedintheinventory.Companiesmayuseotherformatstosummarizethisinformation,butadescriptionoftheinventoryboundariesandtheoperationsincludedintheinventorycanbeveryhelpfulininterpretingtheresultsandisrecommended.Considerationsinvolvedinsettingorganizationalboundariesandinassigningownershipandcontrolofemissions(i.e.,settingorganizationalboundaries)areaddressedinmanyprotocols,includingtheWRI/WBCSDGHGProtocol(WRI2004a).Examplesofpulpandpapermilloperationswiththepotentialtoemitgreenhousegasesinclude:•powerboilers,gasturbines,andothercombustiondevicesproducingsteamand/orpowerforthemill•recoveryfurnacesandotherdevicesburningspentpulpingliquors•incinerators•limekilnsandcalciners•gas-orotherfossilfuel-fireddryers(e.g.,infrareddryers)•anaerobicwastewatertreatmentorsludgedigestionoperations(usuallyincludedintheboundariesoftheinventoryonlyifon-siteorownedbythecompany)•landfillsusedtodisposeofmillwastes(usuallyincludedintheboundariesoftheinventoryonlyifon-siteorownedbythecompany)•on-sitevehiclesandmachinery•harvestingequipmentusedtosupplythemill(usuallyincludedintheboundariesoftheinventoryonlyifownedbythecompany)•trucksusedtotransportrawmaterials,products,orwastesforthemill(usuallyincludedintheboundariesoftheinventoryonlyifownedbythecompany)Examplesofpulpandpapermilloperationsthatmaybeassociatedwiththeindirectemissionofgreenhousegasesbecausetheysometimesconsumepurchasedpowerorsteaminclude:•preparingvirginfiber(debarking,chipping,andotherwoodyardoperations,usuallyincludedonlyifownedbythecompany)•preparingrecoveredfiber,includingdeinking•mechanicalpulping•chemicalpulping•semi-chemicalpulpingVersion1.111July8,2005•otherchemicalpulpingprocesses•chemicalrecoveryoperations•pulpscreening,thickening,andwashing•virginfiberbleachingandrecoveredfiberbleachingandbrightening•on-siteproductionofchlorinedioxideandotherbleachingchemicals•paperandpaperboardproduction,includingstockcleaningandrefining•coating,includingextrusioncoating•trimming,rollwrapping,sheetcutting,etc.•normalofficeandbuildingoperationsformillemployees•equipmentforincomingprocesswatertreatmentandwastetreatment•non-fossilfuel-firedemissioncontroldevices(e.g.,ESPs,biofilters)Thereareseveraltypesofancillaryoperationsthatmaybeassociatedwithmillfacilitiesbutinsomecasesarenotwithintheorganizationalandoperationalboundariesoftheinventory.Thedecisiononwhetherornottoincludeemissionsfromthesesourceswilldependontheboundariesoftheinventory.Examplesoftheseancillaryoperationsinclude:•chemicalplantslocatedatthemillsite•merchantpowerplantslocatedadjacenttothemillwhoseprimarybusinessissellingelectricity•convertingoperationsthatarenotconductedon-siteatmostmills7.0MATERIALITYANDINSIGNIFICANTEMISSIONSGreenhousegasprotocolsgenerallyallowcompaniestoignoreemissionsthataresosmallthattheydonotsignificantlyimpacttheestimationofoverallemissions.Thisconceptof“materiality”isdrawnfromfinancialreporting,whereamaterialdifferenceissometimestakentobeadiscrepancyofmorethan5%betweenreportedandauditedvalues(thoughthisisnotanabsolutestandard)(Loreti,Foster,andObbagy2001).Thereisnogenerallyacceptedstandard,however,formaterialityinGHGinventories(Loreti,Foster,andObbagy2001).TheGHGProtocolprovidesthegeneralguidancethat“informationisconsideredtobematerialif,byitsinclusionorexclusion,itcanbeseentoinfluenceanydecisionsoractionstakenbyusersofit”(WRI2004a).TheGHGProtocolcontinuesthisdiscussion,“whiletheconceptofmaterialityinvolvesavaluejudgment,thepointatwhichadiscrepancybecomesmaterial(materialitythreshold)isusuallypre-defined.Asaruleofthumb,anerrorisconsideredtobemateriallymisleadingifitsvalueexceeds5%ofthetotalinventoryforthepartoftheorganizationbeingverified.”However,“amaterialitythresholdisnotthesameasdeminimisemissions,orapermissiblequantityofemissionsthatacompanycanleaveoutofitsinventory.”Italsoobservesthat“inordertoutilizeamaterialityspecification,theemissionsfromaparticularsourceoractivitywouldhavetobequantifiedtoensuretheywereunderthethreshold.However,onceemissionsarequantified,mostofthebenefitofhavingathresholdislost”(WRI2004a).ThesetoolscontainnospecificrecommendationsonhowtodeterminewhetheremissionsaresosmallthattheycanbeomittedwithoutcausingamaterialdiscrepancyinaGHGinventory,butthetoolsdocontainemissionfactorsandexamplecalculationsthatmayaidcompaniesindecidingwhichemissionsarematerialforthepurposeofreportingandwhicharenot.The12Version1.1July8,2005decisiononwhether,orhow,theestimatesshouldbereportedmaybelefttothecompanyormaydependonwhoitisreportingto.Thatdecisionmaydepend,inpart,onacompany’sassessmentofthequalityofthedatausedtodeveloptheestimateandtheintendeduseoftheinventoryresults.Intheresultsoftheinventory,however,companiesshouldjustifyanyexclusionsofemissionsbasedonmaterialityconsiderations.Furthermore,itisimportanttorecognizethatifseveralminoremissionsourcesareomittedfromtheinventory,eachofwhichwasdeterminedtobeimmaterial,thecummulativeeffectmayaffecttheinventorybyover5%andthusbeamaterialomission.Table1hasbeendevelopedfromrepresentativeemissionfactorsdiscussedinthisreportanditsannexes.Theinformationmayassistcompaniesindeterminingwhichsourcesmustbeincludedintheinventoryandwhicharesosmallthattheycanbeignored.SubsequentsectionsofthisreportprovideemissionfactorsfromtheIPCCandotherreferences.ThefactorsinTable1clearlyillustratetheimportanceofCO2emissionsfromfossilfuelcombustion.Inmostcases,CH4andN2Ocontributerelativelysmallquantitiestoamill’sGHGemissions,evenonaCO2-equivalentsbasis.Inaddition,sourcesotherthanfossilfuelcombustionwillbecomparativelysmall.Othersectionsofthisreportcontainexamplecalculationsthatmaybehelpfulinidentifyinginsignificantsources.Theultimatedecisiononwhichemissionstoinclude,however,mustbemadebythecompanyormaybespecifiedintheGHGreportingprogramguidance.Table1doesnotincludeCO2frombiomasscombustionbecauseundertheGHGProtocolthisCO2isnotincludedinGHGtotalsbutisreportedseparately,asinnationalGHGinventories.Intheresultsoftheinventory,companiesshouldidentifythosesituationswhereemissionshavebeenestimatedtobetoosmalltomateriallyimpactinventoryresults.Theexamplereportingformatpresentedinthisreportallowsthesesituationstobeidentifiedbyreportingthesereleasesas“non-material”or“NM”intheresults.Companiesshouldalsoindicateintheresultsthecriteriausedtodecidewhetheremissionsarenon-material.Afootnotecanbeadded,forinstance,indicatingthattheemissionsarenon-materialbecausetheyrepresentlessthanacertainpercentofthemill’sorcompany’sdirectemissions.Table1.EmissionFactorRangesUsefulinIdentifyingSignificantandInsignificantSourcesofGHGsUnitsFossil-CO2CH4(CO2-equiv.)N2O(CO2-equiv.)TablesinReportContainingDefaultValuesNaturalgasusedinboilerskgCO2-equiv./TJ56,100–57,00013–35731–6202,4,5ResidualoilusedinboilerskgCO2-equiv./TJ76,200–78,00013–6393–15502,4,5CoalusedinboilerskgCO2-equiv./TJ92,900–126,00015–294155–29,800Θ2,4,5BarkandwoodwastefuelkgCO2-equiv./TJ0<21–860<310–80608BlackliquorkgCO2-equiv./TJ042–63015508LimekilnskgCO2-equiv./TJdependsonfuel21–570ψ2,6LimecalcinerskgCO2-equiv./TJdependsonfuel21–571550λ2,6Pulpmillmake-upCaCO3kgCO2/tCaCO3440007Pulpmillmake-upNa2CO3kgCO2/tNa2CO3415007DieselfuelusedinvehicleskgCO2-equiv./TJ74,000–75,30082–231620–97702,9Gasolineinnon-roadmobilesourcesandmachinery–4-strokeengineskgCO2-equiv./TJ69,300–75,30084–30,90093–25802,9Gasolineinnon-roadmobilesourcesandmachinery–2-strokeengineskgCO2-equiv./TJ69,300–75,3009,860–162,000124–8612,9AnaerobicwastewatertreatmentkgCO2-equiv./kgCODtreated05.25η0Eqs.6,7MillsolidwastelandfillskgCO2-equiv./drytonsolidwaste03,500∞0Eqs.1,3,5;Table10CO2-equivalentsarecalculatedfromIPCCGlobalWarmingPotentials(CH4=21,N2O=310).ΘReportedN2Oemissionfactorsgreaterthan1500kgCO2-equiv../TJaregenerallylimitedtofluidizedbedboilers.ψIPCCinformationsuggestsN2Oisnotlikelytobeformedinlimekilnsinsignificantamounts.λAmountsofN2O,ifany,formedincalcinersarenotknown,sothelargestfactorforfuelsnormallyusedinkilnsisshownhere.ηAssumesnocaptureofgasfromthetreatmentplant.∞Assumesthat50%oflandfilledwasteisdegradableorganiccarbon,50%ofthedegradableorganiccarbondegradestogas,50%ofthecarboninthegasiscontainedinmethane,noneofthemethaneisoxidizedinthelandfillcoverorcaptured,andallisreleasedinthesameyearthatthewasteislandfilled.Thismethodisusedhereonlytogenerateanemissionfactorforconsideringwhethertoincludethissourceintheinventory.Morerefinedmethods,whichwillnormallyyieldlowerestimatesofemissions,areexplainedinthecalculationtools.14Version1.1July8,20058.0GREENHOUSEGASEMISSIONSFROMSTATIONARYFOSSILFUELCOMBUSTION8.1CarbonDioxideCarbondioxideemissionsfromstationaryfossilfuelcombustionrepresentthemajorityofGHGemissionsformostpulpandpapermills.EmissionsofCO2areestimatedfromthecarboncontentof,oremissionfactorsfor,allfossilfuelsbeingburned.Insomecases,acorrection(i.e.,areduction)ismadeforunoxidizedcarbon.Companiescanusedatafromoneofthesesources,withthepreferredsourceslistedfirst:•dataonthespecificfuelsbeingusedatthemill•themostappropriatedatarecommendedbynationalauthorities•themostappropriatedataavailablefromothersources,suchastheIPCCItisprudenttorecognizethattheintendedpurposeoftheemissionsinventorymayinfluencetherequiredlevelofresolutionoftheemissionestimates,andthustherequiredspecificityoftheemissionfactorsused(i.e.,aninventorydevelopedforinternalcompanyusemaynotrequirethesameaccuracyandresolutionasaninventorydevelopedforparticipationinanemissionstradingprogram).Wherepossibleandappropriate,itispreferabletoobtainemissionfactorsforfuelscombustedatthefacility,whichareoftenavailablefromthefuelvendor.Thismaybeparticularlyimportantforcoal,asthecarboncontentandheatingvaluesfordifferinggradesofcoalcanvarywidely.Emissionfactorsfornaturalgasmayalsovary,dependingupon,amongotherfactors,whetherornotnon-methanehydrocarbonshavebeenstrippedfromtherawgas.CO2emissionfactorsandinformationonfossilfuelcarboncontentandunoxidizedcarbonareavailablefrommostnationalauthoritiesandavarietyofexistingprotocols.TheIPCCgeneric(Tier1)emissionfactorsareshowninTable2.TocorrectCO2emissionestimatesforunoxidizedcarbon,IPCCrecommendsdefaultcorrectionfactorsof0.98forcoal,0.99foroilandoilproducts,0.995forgas,and0.99forpeat(non-householdusecombustion)(IPCC1997c).TheIPCCemissionfactorsinTable2arepresentedasuncorrectedandascorrectedforunoxidizedcarbonbasedontheserecommendations.IPCCpointsout,however,thatinthecaseofcoal,unoxidizedcarboncanbemuchhigherthanthedefaultvaluesandcitesanAustralianstudyofcoal-firedboilerswhereinunoxidizedcarbonrangedfrom1to12%ofthecarbonfedtotheboiler.Unfortunately,thereisnotaconsensusamongdifferentGHGaccountingandreportingprotocolswithrespecttothemostappropriatecorrectionfactorsforunoxidizedcarbon,asillustratedbytheinformationinTable3.Unlessstatedotherwise,thefactorsandexamplecalculationspresentedinthesetoolsincorporatecorrectionsforunoxidizedcarbonbasedonIPCCrecommendations.Version1.115July8,2005Table2.IPCCDefaultCO2EmissionFactorsforFossilFuels(afterIPCC1997b)FossilFuelUncorrectedEmissionFactorkgCO2/TJCorrectedEmissionFactorkgCO2/TJCrudeoil73,30072,600Gasoline69,30068,600Kerosene71,90071,200Dieseloil74,10073,400Residualfueloil77,40076,600LPG63,10062,500Petroleumcoke100,80099,800Anthracitecoal98,30096,300Bituminouscoal94,60092,700Sub-bituminouscoal96,10094,200Lignite101,20099,200Peat106,000104,900Naturalgas56,10055,900Thesefactorsassumenounoxidizedcarbon.Toaccountforunoxidizedcarbon,IPCCsuggestsmultiplyingbythesedefaultfactors:coal=0.98,oil=0.99,andgas=0.995.Table3.RecommendedCorrectionFactorsforUnoxidizedCarbonfromVariousGuidanceDocumentsSourceCoalOilNaturalGasIPCC(1997c)98%99%99.5%EnvironmentCanada(2004)99%99%99.5%EPAClimateLeaders(USEPA2003)99%99%99.5%DOE1605b(USDOE1994)99%99%99%EPAAP-42(USEPA1996,1998a,b,c)99%99%99.9%TheemissionfactorspresentedinVCR(2004)donotspecifycorrectionfactorsforunoxidizedcarbon,howeverallemissionfactorspresentedinVCR(2004)aredrawnfromEnvironmentCanada2004Inmanycases,totalCO2emissionsfromallsourcesburningasinglefossilfuelatamanufacturingfacilitycanbeestimatedwithoutestimatingtheemissionsfromeachcombustionunitseparately.Forinstance,ifamillisburningnaturalgasinseveralboilersandinfrareddryers,theCO2emissionsfromnaturalgasburningcanbeestimatedfromthetotalgasused.Infact,somemillsmaylackthefuelmeteringdevicesthatwouldberequiredtoestimateemissionsfromeachcombustionunitseparately.Ifamillexportsfossilfuel-derivedCO2,forinstancetoanadjacentprecipitatedcalciumcarbonate(PCC)plant,theseexportsshouldnotbeincludedintheemissionsestimatesbecausethisCO2isnotemittedbythemill.Aseparatelineisincludedintheexampleresultstable(Table13)toreportexportsoffossilfuel-derivedCO2.NCASIhasaccesstodatawhichindicatethatthecombustionefficienciesofsomenaturalgas-firedcombustiondevices(e.g.,sometypesofgas-fireddryers)andemissioncontrol16Version1.1July8,2005devicessuchasRegenerativeCatalyticOxidizers(RCOs)andRegenerativeThermalOxidizers(RTOs)cansometimesberelativelylowcomparedtopowerboilers,allowingaportionofthefueltoexitthecombustiondeviceasmethane.Thisconditionmayexistincombustiondevicesthatoperatewithlowburnertemperatures(theautoignitiontemperatureofnaturalgasisapproximately1000°F,andcombustiontemperaturesofapproximately1475°Farerequiredtoachieve99%combustionefficiency(Lewandowski2000)),insituationswheretheburnerisoperatedatheatinputratesbeloworatthelowendofitsdesignoperatingrange,orindeviceswherethenaturalgasburnersaredamagedorpoorlymaintained.DataprovidedtoNCASIindicatethatunburnedmethaneenteringanRCOeitherfromtheprocessorfromanaturalgasburnerwithintheRCOwillpassthroughuncombustedbecausethecatalystdoesnotoxidizemethaneatthenormaloperatingtemperatureofanRCO.NaturalgasinemissionsfromtheprocessaretypicallyoxidizedinanRTO,whereoperatingtemperaturesareabovetheautoignitiontemperaturesofmethane.However,naturalgas-firedRTOsoperatedinfuelmode(wherenaturalgasisinjectedintotheinletoftheRTOalongwiththeprocessgasesbeingcontrolled)mayemithigherlevelsofuncombustedmethanethanthoseoperatedinburnermode(wherenaturalgasiscombustedintheburner(s)oftheRTO).ThiseffectcanbemorepronouncedinRTOsthatoperatewithoutapurgecycle.ThedatacurrentlyavailabletoNCASIindicatethattheamountsofunburnedmethanearehighlyvariable.Undermostcircumstances,companieswillestimateCO2emissionsbyusingfuelconsumption(activity)dataincombinationwiththemostappropriateemissionfactor.Ifacompanyhasreliableinformationonmethaneemissionsfromnaturalgas-firedcombustiondevices(e.g.,emissiontestingresults)itmayusethisinformationtoadjusttheemissionfactor-derivedestimatesofCO2emissionstoaccountfortheunburnedfuel.AnexampleofthistypeofcalculationcanbefoundinthereportCalculationtoolsforestimatinggreenhousegasemissionsfromwoodproductsmanufacturingfacilities(NCASI2004).Municipalsolidwaste(MSW)ormaterialsderivedfromMSWaresometimesusedasfuel.MSWcontainsacombinationoffossilcarbon(primarilyinplastics)andbiomasscarbon(primarilyinpaperandfoodwaste).IPCCrecommendsthatthecompositionoftheMSW(i.e.,itsfossilcarboncontent)beusedtoestimateemissionsoffossil-CO2.Wherenootherdataareavailable,IPCCrecommendsassumingthat16%ofthewetweightofMSWisfossilcarbonand5%ofthefossilcarbonisunburned(IPCC2000a).Thesecombinedassumptionsyieldafossil-CO2emissionfactorof557kgCO2/wettonneMSWburned.8.2MethaneandNitrousOxideMethaneandnitrousoxideemissionsfromfossilfuelcombustionareusuallyverysmallcomparedtoCO2emissions.Indeed,someinventoryprotocolsdonotaddressCH4andN2Ofromfossilfuelcombustion.BecausesomeinventoriesincludeCH4andN2O,however,theyareaddressedinthesecalculationtools.CompanieswilloftenbeabletousethedatainTable1todemonstratethatemissionsofCH4andN2OfromfossilfuelcombustionareinsignificantcomparedtoCO2emissions.Inothercases,asingleemissionfactormightbeavailablethatincludesfossil-CO2,CH4,andN2OVersion1.117July8,2005emissionsexpressedasCO2-equivalents.Inthiscase,thecompanymaynotneedtoreportthethreegasesseparately.EstimatingCH4andN2Oemissionswillusuallyinvolveselectingtheemissionfactorsbestsuitedtothefuelsbeingburnedandthetypeofcombustionunit.Fornormalfossilfuel-firedcombustiondevicessuchasboilers,recommendedemissionfactorsfollowthisorderofpreference:•dataonthespecificfuelsandcombustiondevicesbeingusedatthemill•themostappropriatedatarecommendedbynationalauthorities•themostappropriatedataavailablefromothersourcesItisprudenttorecognizethattheintendedpurposeoftheemissionsinventorymayinfluencetherequiredlevelofresolutionoftheemissionestimates,andthustherequiredspecificityoftheemissionfactorsused(i.e.,aninventorydevelopedforinternalcompanyusemaynotrequirethesameaccuracyandresolutionasaninventorydevelopedforparticipationinanemissionstradingprogram).AnumberofexistingprotocolsandmostnationalauthoritiespublishfactorsforestimatingemissionsofCH4andN2Ofromfossilfuel-firedboilersandothercombustiondevices.IPCCprovidesTier1andTier2emissionfactorsformethaneandnitrousoxide.TheTier1methodforestimatingemissionsisdescribedbyIPCCasoneinwhichemissionsfromallsourcesofcombustion(ofaparticularfuel)areestimatedonthebasisofthe(total)quantitiesoffuelconsumedandaverageemissionfactors(IPCC1997b,c).IPCCdescribestheTier2methodasoneinwhichemissionestimatesarebasedondetailedfuelandtechnologyinformation.Inotherwords,aTier1analysiscouldbeperformedbasedonfacility-levelfuelconsumptiondata,whereasaTier2analysiswouldrequiresourcebysourcefuelconsumptiondataandassociatedsource-specificemissionfactors.AsanexampleofaTier1approach,amillburningnaturalgasinoneboiler,onedryer,andoneRTOestimatesemissionsbysummingthetotalnaturalgasusedinthesethreedevicesandmultiplyingthisquantitybyanemissionfactorfornaturalgas.AnexampleofaTier2approachforthesamefacilitywouldbetoestimateemissionsfromtheboilerbymultiplyingtheboilerfuelconsumptionbyanemissionfactordevelopedspecificallyforthattypeofboiler,estimateemissionsfromthedryerusingthedryerfuelconsumptiondataandanemissionfactordevelopedforthattypeofdryer,andsoon.TheTier2methodismoredetailedthantheTier1method,andifsource-specificfuelconsumptiondataandemissionfactorsareavailabletheTier2methodmayreturnmoreaccurateresultsthantheTier1method.IPCC’sTier1emissionfactorsformethaneandnitrousoxidearepresentedinTable4.IPCC’sTier2emissionfactors,showninTable5formanyofthefossilfuelsandcombustiondevicesofinteresttotheforestproductsindustry,areusuallypreferredbecausetheyaremorespecifictofueltypeandcombustiondevice.18Version1.1July8,2005Table4.IPCCTier1CH4andN2OEmissionFactorsforStationaryCombustion(fromIPCC1997c)CH4EmissionFactorskg/TJN2OEmissionFactorskg/TJCoal101.4Naturalgas50.1Oil20.6Wood/woodresiduals304Table5.IPCCTier2UncontrolledCH4andN2OEmissionFactorsforIndustrialBoilers(IPCC1997c)FuelTechnologyConfigurationkgCH4/TJkgN2O/TJBituminouscoalOverfeedstokerboilers1.01.6Sub-bituminouscoalOverfeedstokerboilers1.01.6BituminouscoalUnderfeedstokerboilers141.6Sub-bituminouscoalUnderfeedstokerboilers141.6BituminouscoalPulverizedDrybottom,wallfired0.71.6BituminouscoalPulverizedDrybottom,tang.fired0.70.5BituminouscoalPulverizedWetbottom0.91.6BituminouscoalSpreaderstoker1.01.6BituminouscoalFluidizedbedCirculatingorbubbling1.096Sub-bituminouscoalFluidizedbedCirculatingorbubbling1.096Anthracite101.4Residualoil3.00.3Distillateoil0.20.4NaturalgasBoilers1.40.1NaturalgasTurbines0.60.1NaturalgasInt.comb.engine2-cycleleanburn170.1NaturalgasInt.comb.engine4-cycleleanburn130.1NaturalgasInt.comb.engine4-cyclerichburn2.90.1TheseareIPCCTier1genericemissionfactorsforcoalandnaturalgas.Tier2emissionfactorsarenotavailable.BoththeTier1andtheTier2emissionfactorsformethaneandnitrousoxidearebasedonuncontrolledemissions.Thisisunimportantformethanebecausemostemissioncontroldeviceshavelittleimpactonmethaneemissions(IPCC1997c)(exceptionsmayincludethermaloxidizerssuchasRTOs,whichundersomeoperatingconfigurationscanoxidizemethane).Nitrousoxideemissionscanbeimpactedbycontroldevices,butthedataareverylimited(IPCC1997c).WhereN2Oemissionsareimportanttoinventoryresults,companiesVersion1.119July8,2005maywanttodevelopemissionsdata.Inmostcases,however,thedifferencebetweencontrolledanduncontrolledemissionsisexpectedtohavelittleeffectontotalGHGemissions.Therefore,companieswillprobablywanttousetheTier1orTier2emissionfactorsshowninTables4and5unlessotherfactorsthataremoresuitedtoindividualmillcircumstancesareavailable.Methaneandnitrousoxideemissionfactorsforstationaryinternalcombustionengines(e.g.,thoseusedtodriveemergencygeneratorsorturbines)firedwithdieselorgasolinecanbeapproximatedbythefactorsfornon-roadmobilesourcesshowninTable9.Fossilfuelscanbeusedinanumberofdifferentcombustionunitscommonintheforestproductsindustry.SomespecificrecommendationsforestimatingCH4andN2Oemissionsfromcertaintypesofunitsfoundexclusivelyorprimarilyintheforestproductsindustryareshownbelow.Recoveryfurnaces–Inmostcases,onlysmallamountsoffossilfuelareburnedinrecoveryfurnaces.TheCO2releasesfromthefossilfuelcanbeestimatedusingthemethodsdescribedinSection8.1.Wherelargeamountsoffossilfuelsarebeingburned(i.e.,theyrepresentamajorsourceoffuelonanongoingbasis),bestprofessionaljudgmentwillberequiredtoselectthemostappropriateemissionfactorsforCH4andN2O.Inthevastmajorityofcases,however,thesmallamountsoffossilfuelusedintherecoveryfurnacecanbeincludedinthefiringrateusedtoestimateCH4andN2Ofromliquorburning.TheCH4andN2OemissionsfactorsforrecoveryfurnacesareincludedintheSection11.2.Combinationfuel-firedboilersburningbiomassandfossilfuels–Methaneandnitrousoxidereleasesfromboilersaresensitivetocombustionconditions,especiallycombustiontemperature.Inmostcases,thecombustionconditionsincombinationfuelboilersaremorelikethoseinbiomass-firedboilersthaninfossilfuel-firedboilers.Therefore,unlessdataareavailablefromsite-specifictestingonsimilarboilersburningacomparablemixoffuels,itisrecommendedthattheCH4andN2Oemissionsfromcombinationfuel-firedboilersbeestimatedfromthetotalheatinputtotheboilerandCH4andN2Oemissionfactorsforbiomass.TheseemissionfactorsaresummarizedinSection11.2.Insomecases,afacilitymayoperateacombinationfuelboilerwherefossilfuelcomprisesamajorportionofthetotalfueltotheboiler.AlthoughestimatingCH4andN2Oemissionsusingtheapproachoutlinedinthepreviousparagraphisappropriateinthesecases,itisalsovalidtoestimatetheseemissionsbasedonconsumptionratesofeachfossilfuelmultipliedbythefuels’emissionfactors,plustheconsumptionrateofbiomassfuelmultipliedbythebiomassfuels’emissionfactors.Kraftmilllimekilnsandcalciners–Theemissionsfromlimekilnsandcalcinersareuniqueenoughtowarrantseparatediscussion(presentedinSection9andAnnexA).Gas-firedinfrareddryers,incinerators,andothermiscellaneouspulpandpapersources–CO2releasesfromthefossilfuelusedintheseunitscanbeestimatedusingthemethodsdescribedinSection8.1.Lackingsite-specificinformation,companieswilleitherhavetoassumethatthemethaneandnitrousoxideemissionsfromthesesourcesarenegligible20Version1.1July8,2005(basedontheamountsoffuelburned)orusetheTier1emissionfactorsorthosedevelopedforsimilarfuelsburnedinotheroperations.ThedatainTable1suggestthatitshouldberelativelysimpleformanycompaniestodocumentthatthesesourcesofCH4andN2Oaresosmallthattheycanbeignoredintheinventory.ThefossilCO2fromthesesourcescanbeestimateddirectlyfromthecarboncontentofthefuelorCO2emissionfactors,usingthesamemethodsasforotherstationarycombustionunits.8.2.1SummaryofGuidanceforEstimatingMethaneandNitrousOxideEmissionsBasedontheinformationinSection8.2,thefollowinggeneralguidanceisprovidedforestimatingmethaneandnitrousoxideemissions.•Ifthefacilityhasaccesstofacility-levelfuelconsumptiondataonly,thisactivitydatacanbeusedinconjunctionwithTier1emissionfactorstoestimateemissions.•Ifthefacilityhasaccesstocombustiondevice-specificfuelconsumptiondata,thisactivitydatacanbeusedwiththeappropriateTier2(source-specific)emissionfactorswhereavailable,andwithTier1emissionfactorsforcombustiondevicesforwhichnoTier2factorsareavailable(e.g.,gas-fireddryers,RTOs)toestimateemissions.•Ifthefacilityhasaccesstomethaneemissionsdatafromsourcetestingofdevicessuchasnaturalgas-fireddryersandRTOs/RCOs,thisinformationcanbeusedtoadjusttheemissionestimatesderivedfromemissionfactorsandfuelconsumption(activity)data.ExampleCalculation:CO2,CH4,andN2Oemissionsfromnaturalgasuseatasmallmill.Amillusesnaturalgasinasmallboilerandinseveralinfrareddryers.Themill’srecordsindicatethatoverayear’stime,itused17millionstandardcubicmetersofnaturalgas.Themilldecidestoestimatetheemissionsfromoverallnaturalgasconsumptioninsteadofattemptingtoseparateboileremissionsfromtheinfrareddryeremissions.Themilldoesnotknowthecarboncontentofitsgassupply,buttheIPCCemissionfactoris55.9metrictonsCO2/TJ(aftercorrectingfor0.5%unoxidizedcarbon).ThemillusestheCH4andN2OemissionfactorsfromTable4(5kgCH4/TJand0.1kgN2O/TJ).Themillestimatestheheatingvalueofthenaturalgastobe52TJ/kilotonandthedensitytobe0.673kg/standardcubicmeter.Theannualemissionsareestimatedasfollows.CO2emissions:•(17x106m3gas/y)x(0.673kg/m3)=11.4x106kggas/y=11.4ktonnegas/y•(11.4ktonnegas/y)x(52TJ/kiloton)=595TJ/y•(595TJ/y)x(55.9tCO2/TJ)=33,300tonneCO2/yCH4emissions•(595TJNCV/y)x(5kgCH4/TJNCV)=2975kgCH4/y=2.975tonneCH4/yUsingtheIPCCGWPof21,thisisequalto62.5tonneCO2-eq./yN2Oemissions•(595TJNCV/y)x(0.1kgN2O/TJNCV)=59.5kgN2O/y=0.06tonneN2O/yUsingtheIPCCGWPof310,thisisequalto18tonneCO2-eq./yTotalGHGemissions=33,300+62.5+18=33,400tonneCO2-equivalents/yVersion1.121July8,2005OnaCO2-equivalentsbasis,CH4andN2Oemissionsareapproximately0.25%ofCO2emissions.Theseemissionswouldbeverysmalleveniftheemissionfactorswereseveraltimeslarger.Becauseofthis,thecompanymightdecideagainstincludingCH4andN2Oestimatesintheresults,andinsteadindicateintheresultsthattheestimatesdemonstratethattheemissionsarenotmaterialtotheresultsoftheinventorybecausetheyarelessthan0.25%ofCO2emissions.ExampleCalculation:CO2,CH4,andN2Oemissionsfromalargedry-bottom,wallfiredboilerburningpulverizedbituminouscoal.Theboilerproduces350,000kgsteamperhour(about770,000pounds/hr).Overayear’stime,themill’srecordsindicatethattheboilerconsumed336,000Mg(370,000shorttons)ofcoalhavingahigherheatingvalue,onaverage,of13,000BtuHHV/lb.Case1:CO2emissionsbasedoncarboncontentoffuelThemillhasinformationonthecarboncontentofthecoalbeingburnedintheboiler(80.1%carbon,byweight).ThemilldecidesthatthedefaultIPCCcorrectionforunburnedcarbonincoal-firedboilers(2%unburnedcarbon)isappropriate.ThemilldecidestousetheTier2IPCCemissionfactorsforCH4andN2OfromTable5.TheIPCCTier2emissionfactorsfordrybottom,wallfiredboilersburningpulverizedbituminouscoalare0.7kgCH4/TJNCVand1.6kgN2O/TJNCV.ThemillappliestheusualassumptionthattheNCV(orLHV)forcoalis5%lowerthantheGCV(orHHV).TheannualemissionsofCO2,CH4,andN2Oareestimatedasfollows.CO2emissions:•(336,000Mg/ycoal)x(0.801Mgcarbon/Mgcoal)x(0.98Mgcarbonburned)x(44MgCO2/12Mgcarbon)=967,000MgCO2/yror967x103tCO2/yrCH4emissions:•370,000shorttonscoal/y=740x106pounds/y•(740x106pounds/y)x(13,000BtuHHV/pound)=9.62x1012BtuHHV/y•forcoal,LHVis0.95timesHHV(seeSection4.4.2)•(9.62x1012BtuHHV/y)x(0.95tocorrecttoLHV)=9.14x1012BtuLHV/y•(9.14x1012BtuLHV/y)x(1055J/Btu)=9.64x1015JNCV/y=9.64x103TJNCV/y•CH4emissions=(9.64x103TJNCV/y)x(0.7kgCH4/TJNCV)=6.75x103kgCH4/yor6.75tCH4/yUsingtheIPCCGWPof21forCH4,thisequatesto142tCO2-eq./yN2Oemissions:•N2Oemissions=(9.64x103TJNCV/y)x(1.6kgN2O/TJNCV)=15.4tN2O/yrUsingtheIPCCGWPof310forN2O,isto4780tCO2-eq./yTotalGHGemissions=967,000+142+4,780=972,000tCO2-equivalents/y22Version1.1July8,2005ComparedtoitsCO2emissions,emissionsofCH4andN2Ofromthisboilerareverysmall.CO2emissions=967,000tCO2/yCH4emissions=142tCO2-eq./yor0.015%ofCO2emissionsN2Oemissions=4,780tCO2-eq./yorabout0.5%ofCO2emissionsExampleCalculation:CO2,CH4,andN2Oemissionsfromalargedry-bottom,wallfiredboilerburningpulverizedbituminouscoal.Theboilerproduces350,000kgsteamperhour(about770,000pounds/hr).Overayear’stime,themill’srecordsindicatethattheboilerconsumed336,000Mg(370,000shorttons)ofcoalhavingahigherheatingvalue,onaverage,of13,000BtuHHV/lb.Case2:CO2emissionsbasedonemissionfactorsInthiscasethemilldoesnothaveinformationonthecarboncontentofthecoalbeingburnedintheboiler.TheIPCCdefaultTier1emissionfactorforCO2is94.6tCO2/TJNCV.ThemilldecidesthatthedefaultIPCCcorrectionforunburnedcarbonincoal-firedboilers(2%unburnedcarbon)isappropriate.CO2emissions:•370,000shorttonscoal/y=740x106pounds/y•(740x106pounds/y)x(13,000BtuHHV/pound)=9.62x1012BtuHHV/y•forcoal,LHVis0.95timesHHV(seeSection4.4.2)•(9.62x1012BtuHHV/y)x(0.95tocorrecttoLHV)=9.14x1012BtuLHV/y•(9.14x1012BtuLHV/y)x(1055J/Btu)=9.64x1015JNCV/y=9.64x103TJNCV/y•uncorrectedCO2emissions=(9.64x103TJNCV/y)x(94.6tCO2/TJNCV)=912x103tCO2/y•CO2emissionscorrectedfor2%unburnedcarbon=894x103tCO2/yMethaneandnitrousoxideemissionsarecalculatedasinCase1.CO2emissions=894,000tCO2/yCH4emissions=142tCO2-eq./yor0.016%ofCO2emissionsN2Oemissions=4,780tCO2-eq./yorabout0.5%ofCO2emissionsAsinthepreviousexample,thiscomparisonsuggeststhatitmayberelativelysimpleformanymillstodocumentthatemissionsofCH4andN2Ofromfossilfuel-firedboilersarenotmaterialtotheresultsoftheirinventory.9.0EMISSIONSFROMKRAFTMILLLIMEKILNSANDCALCINERSFossil-CO2emissionsfromkraftmilllimekilnsandcalcinersareestimatedusingthesameapproachasusedforotherstationaryfossilfuelcombustiondevices–bydetermininghowmuchfossilfuelisusedinthekilnandestimatingemissionsfrominformationonthefuelcarboncontentoremissionfactors.TheseCO2emissionsarereportedtogetherwithotherfossilfuel-relatedCO2emissions.Version1.123July8,2005AlthoughCO2isalsoliberatedfromtheCaCO3burnedinthekilnorcalciner,thecarbonreleasedfromCaCO3isbiomasscarbonthatoriginatesinwoodandshouldnotbeincludedinGHGemissionstotals.CompanieswantingtoprepareinventoryreportsthatareconsistentwiththerequirementsoftheWRI/WBCSDGHGProtocolshouldreportthesebiomass-relatedemissions,butkeepthemseparatefromdirectemissionsfromfossilfuelcombustion.AnnexEprovidesanexampleformatthatcanbeusedforreportingthisadditionalinformation.Themovementofcarboninkraftpulpmillsandthereasonsfordifferentiatingbiomass-fromfossil-CO2emissionsfromlimekilnsareexploredindetailinAnnexAtothisreportandinapaperbyMinerandUpton(2002).ThereareveryfewdataonCH4andN2Oemissionsfromkraftmilllimekilnsandcalciners.Thisreviewuncovereddatafromonlythreelimekilnssampledintheearly1980s(NCASI1981).Thesedatasuggestanemissionfactorof2.7kgCH4/TJ.Forcommerciallimekilns,IPCCsuggestsemissionfactorsof1.0and1.1kgCH4/TJforoil-firedandgas-firedlimekilns,respectively.TheIPCCfactorsareforcommerciallimekilns,however,andmaynotbeappropriateforkraftmilllimekilns.Table1illustratesthatforfossilfuel-firedkilnsorcalciners,CH4emissionswillbeverysmallcomparedtotheCO2fromfossilfuel.NodatawerefoundforN2Ofromlimekilnsorcalciners,butthetemperaturesinrotarylimekilnsappeartobetoohightoallowsignificantgenerationofN2O(seeAnnexAformoreinformation).Itisreasonable,therefore,toassumethatN2Oemissionsfromrotarylimekilnsarenegligible.ThetemperaturesincalcinersappeartobemoreamenabletoN2Ogeneration(seeAnnexA).GiventherangeofN2Oemissionfactorsforoilandgas,however,itseemslikelythatN2Oemissionswillbesmallrelativetofossil-CO2emissionsfromfossilfuel-firedcalciners.TheemissionfactorssuggestedforkraftmilllimekilnsandcalcinersaresummarizedinTable6.Atanumberofmillsaroundtheworld,stackgasfromlimekilnsorcalcinersispipedtoadjacentprecipitatedcalciumcarbonate(PCC)plantsforuseasarawmaterial(PCCissometimesusedasaninorganicfillerorcoatingmaterialinpaperandpaperboardproducts).AseparatelineisincludedintheexampleinventoryresulttablestoshowtheamountsoffossilfuelCO2beingexportedtoPCCplants.Theseexportsoffossilfuel-derivedCO2shouldnotbeincludedintheestimatesofGHGemissionsbecausetheyarenotemittedbythemill.Ifthemillalsowantstoshowtheamountsofbiomass-derivedCO2thatareexportedwithlimekilnstackgas,itcanincludethisasadditionalinformation(seeAnnexE).AmillmaysometimesexportCO2tothePCCplantwhenthePCCplantisnotoperating.ThesecalculationtoolsdonotrequirethattheexportsbecorrectedtoaccountfortheseperiodsbecausethemillnolongerownstheexportedCO2andcannotcontrolwhetherthePCCplantusesit.Presumably,ifthePCCplantweretoconductaninventory,anyunusedfossil-CO2receivedfromthemillwouldbeshownasadirectemissioninitsinventory.ExportsoffossilfuelCO2toPCCplantsareshownintheresultstable(Table13).ThistableisalsousedtoshowanyimportsofCO2tothemill;foruseinneutralization,forinstance.24Version1.1July8,2005Table6.EmissionFactorsforKraftMillLimeKilnsandCalcinersEmissions,kg/TJFuelKraftmilllimekilnsKraftmillcalcinersCO2CH4N2OCO2CH4N2OResidualoil76,6002.7θ0χ76,6002.7θ0.3φDistillateoil73,4002.7θ0χ73,4002.7θ0.4φNaturalgas55,9002.7θ0χ55,9002.7θ0.1φBiogas02.7θ0χ02.7θ0.1δFromTable2,correctedforunburnedcarbonθFromNCASI1981χBasedonIPCCdescriptionoftemperaturesgivingrisetoN2OemissionsφFromTable5δAssumedappropriatetousetheemissionfactorfornaturalgas,asthecompositionandcombustionconditionsforbiogasaremoresimilartonaturalgasthantootherfuelsThesedraftcalculationtoolsdonotaddresstheultimatefateofexportedCO2ortheownershipofanyCO2thatisultimatelyemittedfromthePCCplant,asbothissuesareoutsidetheboundaryofpulpandpaperoperations.NordoesitaddressthequestionofhowmuchofthiscarbonissequesteredasaresultofbeingconvertedtoPCC.Ultimately,however,mostofthecarboninPCCissequesteredinlandfilledpaper,landfilledresidualsfromdeinkingmills,orashfromburningusedpaper.ExampleCalculation:GHGemissionsfromanaturalgas-firedlimekiln.A1000ton/daykraftmillhasasinglegas-firedlimekiln.Themill’srecordsindicatethatitused28.6x106poundsofgaslastyearwithatypicalheatcontentof21,000BtuHHV/lbandadensityof0.77kg/m3.TheIPCCCO2emissionfactorfornaturalgasfromboilerscanbeusedforlimekilnssincetheCO2emissionsareafunctiononlyofgascomposition.TheIPCCCO2emissionfactorfornaturalgasis55.9tCO2/TJ(aftercorrectingfor0.5%unoxidizedcarbon).ForCH4,themilldecidestousetheonlyavailableemissionfactorforkraftmilllimekilns(2.7kgCH4/TJ)andassumesthatN2OemissionsarenegligiblebasedontheIPCCdiscussionoftemperaturesneededtogenerateN2O.Thekiln’sGHGemissionsareestimatedasfollows.CO2emissions:•28.6x106poundsgas/yx21,000BtuHHV/lb=601x109BtuHHV/y•fornaturalgas,LHVis0.9timesHHV(seeSection4.4.2)•601x109BtuHHV/yx0.9(toconverttoLHV)=541x109BtuLHV/y•541x109Btu/yx(1.055x10-6GJ/Btu)=570,000GJ/y=570TJ/y•570TJ/yx55.9tCO2/TJ=31,900tCO2/yVersion1.125July8,2005CH4emissions:•570TJ/yx2.7kgCH4/TJ=1540kgCH4/yrUsingtheIPCCCO2equivalencyfactorof21,thisequals32tCO2-equivalents.ThisisaverysmallnumbercomparedtotheCO2emissions(31,900t).Inaddition,theestimateisbasedonasmallandolddataset.Consequently,intheinventoryresultsthemillmightdecidetoreportthattheCH4emissionsfromthissourcearenon-materialtotheinventory.N2Oemissions:•AsdiscussedaboveandinmoredetailinAnnexA,IPCC’sanalysisofthetemperaturesneededtoformN2OincombustionprocessessuggeststhatitisunlikelythatsignificantamountsofN2Owouldbeformedinlimekilns.Themillwouldprobablydecidetonotethisintheinventoryresults.TotalGHGemissions=31,900+32+0=31,900CO2-equivalents/y10.0CARBONDIOXIDEEMISSIONSFROMMAKE-UPCHEMICALS10.1EmissionsfromMake-upCarbonatesUsedinthePulpMillAlthoughlossesofsodiumandcalciumfromtherecoverysystemareusuallymadeupusingnon-carbonatechemicals,smallamountsofCaCO3andNa2CO3aresometimesused.Thecarboncontainedinthesechemicalsisusuallyoffossilorigin,althoughinsomecases(e.g.,Na2CO3purchasedfromsoda-basedsemi-chemmills)itcanbederivedfrombiomass.Inthesecalculationtools,itisassumedthatthecarboninthesemake-upchemicalsescapesasCO2fromthelimekilnorrecoveryfurnace.TheseemissionsareestimatedbyassumingthatallofthecarboninCaCO3andNa2CO3usedintherecoveryandcausticizingareasisreleasedtotheatmosphere.Theamountsareusuallysmallenoughthatundernormalcircumstancesitisreasonabletouseeithermillpurchasingrecordsorindustrynormstodeveloptheestimates.Ifthecarboninmake-upchemicalsisbiomassinorigin(anuncommonsituation),theCO2releasedfromitisnotconsideredaGHGemission,andinthesecasesthiscarbondoesnotneedtobeincludedinGHGtotals,althoughtheGHGProtocolrequiresthatitbeincludedinthereportasadditionalinformation.SeeAnnexEformoreinformation.Theconversionfactorsforestimatingfossil-CO2releasesfromtheuseofcarbonate-basedmake-upchemicalsinthepulpmillareshowninTable7.Table7.EmissionsfromCalciumCarbonateandSodiumCarbonateMake-upinthePulpMillEmissionsPulpmillmake-upCaCO3440kgCO2/tCaCO3Pulpmillmake-upNa2CO3415kgCO2/tNa2CO3Ifthecarbonateisderivedfrombiomass,GHGemissionsarezeroItisimportanttonotethatcalciummake-upisrequiredbecauseoflossesfromthecausticizingarea,mostofwhichareintheformofcalciumcarbonate.Thislostmaterialis26Version1.1July8,2005usuallylandfilled,therebysequesteringthecarboncontainedinthecalciumcarbonate.Becausethedefaultmethodinthesecalculationtoolsdoesnotconsiderthislossofcarbonfromthesystem,theestimatedCO2emissionsfrommake-upcalciumcarbonatewillbehigherthanactualemissions.Wheretheseemissionsaresignificant,companiesmaywanttoperformthemoredetailedanalysesrequiredtocorrecttheemissionsestimatestoaccountforthecarbonthatleavesthecausticizingareaincalciumcarbonate.ExampleCalculation:KraftmillusingCaCO3formake-upatthelimekiln.A2000tpdkraftmilldeterminedfrommillrecordsthatitusesabout7000t(7700shorttons)CaCO3ayearasmake-upinthecausticizingarea(make-uprateofabout2%forthismill).ThisCaCO3isfromasourcewherecarbonatewouldbeexpectedtobefossil(notbiomass)inorigin.Theemissionsareestimatedasfollows.•(7000tCaCO3/y)x440kgCO2/tCaCO3=3,080,000kgCO2/y=3080tCO2/y10.2EmissionsfromLimestoneorDolomiteUsedinFlueGasDesulfurization(FGD)SystemsLimestone(CaCO3)anddolomite(CaCO3MgCO3)1arebasicrawmaterialsusedbyawidevarietyofindustries,includingasasorbentinfluegasdesulfurization(FGD)systemsandfluidizedbedboilersatelectricutilityandindustrialplants.Forexample,wetlimestone“scrubbers”uselimestoneslurries–mixturesofwaterandveryfinelycrushedlimestone–topreventsulfurdioxidefrompassingthroughsmokestacks.Arapidchemicalreactionbetweensulfurdioxidegasandcrushedlimestonecombinesthegaswithcalciumandoxygen,formingaremovablesolidwaste.DuringthisreactionthelimestoneisheatedandCO2isgeneratedasaby-product.Somecoal-firedboilersatpulpandpapermillsincorporatesuchFGDsystems.Carbondioxideemissionsassociatedwiththeuseoflimestoneasasorbentmaterialcanbecalculatedbymultiplyingthequantityoflimestoneordolomiteconsumedbyitsaveragecarboncontent,approximately12%bymassforlimestoneand13%fordolomite(basedonstoichiometry).Thisapproachassumesthatallcarboninthemineralisoxidizedandreleasedandthatimpuritiesconstituteaminorfractionofthematerial.ConvertingthesepercentagestoamassratioofCO2tolimestoneusingamolecularweightratioproducesemissionfactorsof0.440tonneCO2/tonnelimestoneconsumedand0.447tonneCO2/tonnedolomiteconsumed.Thequantityoflimestoneconsumedcanbeestimatedbasedonpurchaserecordsormetereddata(e.g.,scales).Thelimestoneusedforindustrialpurposesisoftenacombinationofpurelimestone,dolomite,andminorimpurities(e.g.,magnesia,silica,andsulfur).UncertaintiesinestimatesofCO2emissionsfromlimestoneusedassorbentsaredue,inpart,tovariationsinthechemicalcompositionoflimestone.1Limestoneanddolomitearecollectivelyreferredtoaslimestonebytheindustry,andintermediatevarietiesareseldomdistinguished.Version1.127July8,200511.0EMISSIONSFROMSTATIONARYCOMBUSTIONOFBIOMASSFUELS11.1ReleasesofBiomass-DerivedCarbonDioxidefromBurningBiomassFuelsManypulpandpapermillsgeneratemorethanhalftheirenergyneedsfrombiomassfuelsrecoveredfromtheindustry’swasteandprocessstreams.TheCO2generatedwhenbiomassfuelsareburnedisnotincludedinGHGemissiontotals.TheGHGProtocol,however,requiresthatbiomass-derivedCO2bereportedasadditionalinformation.ThisistheapproachgenerallyprescribedfornationalinventoriesbytheUnitedNationsFrameworkConventiononClimateChange.Therefore,inkeepingwithwell-establishedpractices,theGHGinventoryresultsgeneratedusingthesecalculationtoolsdonotincludeCO2emissionsfrombiomassburning,butmethodsareprovidedforestimatingbiomass-derivedCO2sothatitcanbereportedwhereneeded(seeAnnexE).Anyincreasesordecreasesintheamountofcarbonsequesteredbytheforestsareaccountedforinthecomprehensiveforestaccountingsystem.ThisistheapproachgenerallyprescribedfornationalinventoriesbytheUnitedNationsFrameworkConventiononClimateChange.Mostinternationalprotocols,includingthatoftheIPCC,haveadoptedtheconventionsetoutbytheUnitedNations.TheIPCChasstatedthatemissionsfrombiomassdonotaddtoatmosphericconcentrationsofcarbondioxide(IPCC1997a,c).Therefore,inkeepingwithwell-establishedpractices,thegreenhousegasinventoryresultsgeneratedusingthesecalculationtoolsdonotincludeCO2emissionsfrombiomassburning.TheWRI/WBCSDGHGProtocolandsomenationalreportingschemes,however,requirethattheseemissionsbeestimatedandreported,butkeptseparatefromdirectGHGemissions.Thesecalculationtoolsprovideavenueforthis,withbiomasscombustionCO2emissionsreportedseparately.AnnexEcontainsinformationthatwillassistcompaniesthatwanttocomplywiththeserequirements.IPCCprovidesalistofbiomassfuels(IPCC1997a,c):•woodandwoodresiduals(althoughbiogasfromwoodresidualsandotherbiomassisnotspecificallylistedbyIPCC,itclearlyfallswithinthegeneraldefinitionofbiomass)•charcoal•dung•agriculturalresiduesandwastes•municipalandindustrialwastes,wheretheorganicmaterialisbiologicalinorigin(thiswouldincludewastewatertreatmentsludgesfrompulpandpapermills)•bagasse•bio-alcohol•blackliquor•landfillgas•sludgegasCO2emissionsfrompeatburningareusuallyconsideredtobeGHGsandareincludedintheemissionsfromfossilfuelburning(Table2).28Version1.1July8,2005Non-condensablegases(NCGs)consistofreducedsulfurcompoundsandotherorganiccompoundsthatareformedduringthekraftpulpingprocess.Thesegasesareoftencollectedandburnedinboilers,limekilns,orincineratorsasapollutionabatementprocedure.BecausethecarboninNCGsoriginatedinwood,theCO2generatedduringcombustionofNCGsisofbiomassoriginandis,therefore,notincludedinatabulationofdirectGHGemissions.ThequantitiesofNCGscombustedatkraftmillsareverylowrelativetoquantitiesofspentpulpingliquorsandotherwoodresidualsfuels.TherearenodataonmethaneornitrousoxidegenerationfromcombustionofNCGs.11.2MethaneandNitrousOxideEmissionsfromBurningBiomassFuelsAlthoughCO2frombiomassburningisalmostuniversallyexcludedfromGHGinventories,CH4andN2OfrombiomassburningaresometimesincludedbecausethesegasesdonotparticipateintheatmosphericCO2sequestration-recyclingprocessexplainedinSection11.1.Therefore,calculationtoolsareprovidedtoassistinestimatingtheseemissions.Ifacompanyhasreliablesite-specificdataallowingittoestimateCH4andN2Oemissionsfrombiomasscombustion,itshouldusethosedata.Otherwise,itwillbenecessarytousethemostappropriateemissionfactorsavailable.Unfortunately,therearefewdataonCH4andN2Oemissionsfrombiomasscombustion.IPCC’sRevised1996InventoryGuidelinesusedemissionfactorsdevelopedbyEPA.Thisisalsotrueforanumberofcountries.EPAhassincerevisedthesefactors.EventheupdatedEPAfactors,however,arebasedonveryfewdata.Table8providesasummaryoftheavailableinformationonmethaneandnitrousoxideemissionsfrombiomassboilers.TheIPCCTier1emissionfactorsforcombustionof“wood,woodresiduals,andotherbiomassandwastes”arealsoshowninTable8.ThemanyindividualcountryfactorsthatarebasedonIPCCorEPAfactorsarenotshown.Thevariabilityinthedatareflectsthemanydifferenttypesandagesofboilerstested,operatingconditions,controlequipment,andfuelcharacteristics.AsdiscussedinSection11.1,therearenodataonmethaneornitrousoxideemissionsfromcombustionofNCGsgeneratedduringthekraftpulpingprocess.WhereanemissionfactorshowninTable8wasdevelopedforcircumstancesthatmatchconditionsatamill,thecompanymaywanttoselectthatemissionfactorforestimatingemissions.Forinstance,companieswithfluidizedbedboilersmaywanttousetheFortumemissionfactorsbecausetheyweredevelopedonfluidizedbedboilerswhiletheotheremissionfactorsweredevelopedonstokerboilersoronboilersofanunspecifieddesign.Inmanycases,however,becauseoftherangesinemissionfactorsandthelimitedabilityatthistimetomatchemissionfactorstoboilerdesigns,operatingconditions,andfuels,itisreasonabletousethemedianemissionfactorsshowninthetabletocharacterizeemissionsfromboilers.ThesemedianemissionfactorsfallwithintherangescitedintheCORINAIRemissionsinventory(rangesalsoshowninthetable)(EEA2004).Forwood-firedcombustionequipmentotherthanboilers,itmaybemostappropriatetousetheIPCCTier1emissionfactorsshowninTable4.Insomecases,afacilitymaychoosetobaseemissionestimatesonfacility-levelfuelconsumptiondatainconjunctionwiththeTier1emissionfactors.Version1.129July8,2005Table8.EmissionFactorsforCH4andN2OfromBiomassCombustionEmissionFactorDescriptionkgCH4/TJkgN2O/TJReferenceWoodwaste-firedboilersWood,woodwaste,andotherbiomassandwastes304Tier1–IPCC1997cUncontrolledemissionsfromwood-firedstokerboilers15-Tier2–IPCC1997cAverageforwoodresiduecombustion9.55.9USEPA2001Averageforcirculatingfluidizedbedboilersburningpeatorbark18.8Fortum2001Averageforbubblingfluidizedbedboilersburningpeatorbark2<2Fortum2001Pre-1980woodresidue-firedstokerboilerssampledaheadofcontroldevices8.2-NCASI1980Pre-1980woodresidue-firedstokerboilerssampledafterwetscrubbers2.7-NCASI1985Woodfiredboiler41λ3.1λJPA2002Woodasfuel24λ3.4λAEATech.2001Woodwaste305SwedishEPA2004Medianemissionfactorsforwoodwaste1241-401.4–75EEA2004RecoveryfurnacesRecoveryfurnace<1<1Fortum2001Recoveryfurnace–blackliquor2.5Ω-JPA2002BlackLiquor305SwedishEPA2004Medianemissionfactorsforblackliquor2.521–17.71–21.4EEA2004ConvertedfromGCVtoNCVassuminga5%differenceExcludesoneveryhighnumberassociatedwithlowoxygen-highcarbonmonoxideconditionsλBasedonheatcontentof20GJ/tdrysolidsΩBasedonliquorheatcontentof13.3GJ/tdrysolids11.2.1CombinationFuel-FiredBoilersBurningBiomassandFossilFuelsAsdiscussedinSection8.2.1,methaneandnitrousoxidereleasesfromboilersaresensitivetocombustionconditions,especiallycombustiontemperature.Inmostcases,thecombustionconditionsincombinationfuelboilersaremorelikethoseinbiomass-firedboilersthanfossilfuel-firedboilers.Methaneandnitrousoxideemissionsareoftenmoredirectlyrelatedtocombustionconditionsthantofueltype.Becauseofthehighmoisturecontentofmostwood-basedfuels,areasonabledefaultistoassumethatthecombustionconditionsincombinationfuel-firedboilersreflecttheimpactofthewoodresidualfuels.Therefore,unlessdataareavailablefromsite-specifictestingonsimilarboilersburningacomparablemixoffuels,orunlessthecombustionconditionsinthecombinationfuel-firedboileraremorelikefossilfuel-firedboilersthanwoodresidualfuelboilers,itisrecommendedthatthe30Version1.1July8,2005emissionsfromcombinationfuel-firedboilersbeestimatedfromthetotalheatinputtotheboilerandCH4andN2Oemissionfactorsforbiomass.Insomecases,afacilitymayoperateacombinationfuelboilerwherefossilfuelcomprisesamajorportionofthetotalfueltotheboiler.AlthoughestimatingCH4andN2Oemissionsusingtheapproachoutlinedinthepreviousparagraphisappropriateinthesecases,itisalsovalidtoestimatetheseemissionsbasedonconsumptionratesofeachfossilfuelmultipliedbythefuel’semissionfactors,plustheconsumptionrateofbiomassfuelmultipliedbythebiomassfuel’semissionfactors.ExampleCalculation:Millwithabarkboiler.Amillhasa250,000kgsteam/hour(550,000pound/hr)circulatingfluidizedbed(CFB)barkboiler.Inayear,theboilerburnsapproximately6.9x106GJofbarkand0.8x106GJofresidualfueloil.Becausetheboilerreceivessupplementalfossilfuel,itisnecessarytoestimatetheCO2fromthefossilfueluseandtheCH4andN2Oemissionsbasedonthetotalfiringrate.ThemilldecidestousetheIPCCemissionfactorforresidualoil(76.6tCO2/TJ,aftercorrectingfor1%unoxidizedcarbon)andtoestimateCH4andN2OemissionsbasedonthetotalfiringrateandtheemissionfactorsdevelopedbyFortumonCFBboilers.TheaverageemissionfactorsfoundbyFortum,showninTable8,are1kgCH4/TJand8.8kgN2O/TJ.CO2emissionsfromfossilfuel:•(0.8x106GJ/y)=(0.8x103TJ/y)•(0.8x103TJ/y)x(76.6tCO2/TJ)=61,300tCO2/yCH4emissions:•totalheatinput=(6.9x106GJ/y)+(0.8x106GJ/y)=7.7x106GJ/y=7.7x103TJ/y7.7x103TJ/yx1kgCH4/TJ=7,700kgCH4/y=7.7tCH4/yUsingtheIPCCwarmingpotentialof21,thisequatesto162tCO2-eq./y.N2Oemissions:•totalheatinput=7.7x103TJ/y•7.7x103TJ/yx8.8kgN2O/TJ=67,800kgN2O/y=67.8tN2O/yUsingtheIPCCwarmingpotentialof310,thisequatesto21,000tCO2-eq./yTotalCO2equivalentsemitted=61,300+162+21,000=82,500tCO2-equivalents/y12.0EMISSIONSATTRIBUTABLETOIMPORTSANDEXPORTSOFELECTRICITYANDSTEAMTheconsumptionofpowerorsteam(orhotwater)purchasedfromanothercompanyusuallyresultsinthegenerationofindirectemissions–i.e.,“emissionsthatareaconsequenceofactivitiesofthereportingcompany,butoccurfromsourcesownedorcontrolledbyanothercompany”(WRI2004a).Ofcourse,virtuallyeveryrawmaterial,energysource,andserviceusedbyacompanyhasanindirectemissionsimpact.ManyGHGaccountingprotocols,Version1.131July8,2005however,selectivelyincludeindirectemissionsrelatedtoelectricalpowerandsteamconsumptionbecausetheyareapplicabletoawiderangeofactivitiesandcanbeasignificantcomponentofacompany’stotalGHGimpact.Thecalculationtoolspresentedinthisreport,therefore,addressindirectemissionsfromelectricityandsteam(orhotwater)transfers.Likemostexistingprotocols,thesetoolsrecommendthatindirectemissionsbereportedseparatelyfromdirectemissions.12.1EmissionFactorsforPurchasedPowerandSteamElectricalpowercompaniesandnationalauthoritiespublishinformationontheemissionsgeneratedinproducingelectricalpoweronanationalorregionalbasis,soitisrelativelyeasytoestimatetheindirectemissionsassociatedwithpurchasedpower.Itisoftendifficult,however,todeterminewhetherpublishedemissionfactorsforelectricalpowerincludeallGHGsoronlyCO2emissions.ThedifferenceisusuallyunimportantbecauseCO2representsthegreatmajorityoftheemissionsinmostsituations.Forpurposesofthesecalculationtools,therefore,itisassumedthatpurchasedpoweremissionfactorsaddressallGHGsandarereportedinCO2-equivalents.Whereemissionfactorsareavailableforindividualgasesassociatedwithelectricalpower,theindividualgasescanbereportedseparatelyandthencombinedintocarbondioxideequivalents,ortheindividualemissionfactorscanbecombinedintoasingleCO2-equivalentsemissionfactor.Electricalpowertransmissionlossesvaryfromlocationtolocation.Insomecases,theyaresosignificantthattheyprovideanimportantrationalefordistributedpowergeneration.However,publishedGHGemissionfactorsforpurchasedpowerseldomincorporatetheeffectsoftransmissionlosses.TheGHGProtocol,forexample,statesthat“endconsumersof…purchasedelectricitydonotreportindirectemissionsassociatedwith[transmissionanddistribution]losses…becausetheydonotownthe[transmissionanddistribution]operationwheretheelectricityisconsumed([transmissionanddistributionloss])”(WRI2004a).Furthermore,acceptedGHGprotocolsseldomaskusersofelectricalpowertoaccountfortransmissionlosses.Thus,thesetoolsrecommendtheuseofemissionfactorsforpurchasedpowerthatdonotincludetransmissionlosses.Iftransmissionlossesareparticularlyimportant,however,thiscanbenotedintheresultsandtheimpactcanbeestimatedinsupportinginformation.Inaddition,somepublishedemissionfactorsforpurchasedpowerare“fullfuelcycle”emissionfactorsthatincludeupstreamemissionsfromfuelproduction.Becausefullfuelcycleemissionfactorsarenotthenorm,thesecalculationtoolsrecommendthatpurchasedpoweremissionfactorsbebasedonlyontheemissionsfromthepowerproducersandnottheirupstreamemissions.Ifcompaniesmustusefullfuelcycleemissionfactors(e.g.,tosatisfynationalreportingrequirements),thisshouldbenotedintheresults.12.2ElectricityImportsToestimateindirectemissionsassociatedwithimportedpowerthatisconsumed,companiesshouldusethemostappropriatepurchasedpoweremissionfactoravailable;i.e.,onethatreflectstheemissionsgeneratedduringtheproductionofthepowerbeingpurchased.Atmostpulpandpapermills,powerimportsarefrombaseloads.Inmostcases,therefore,the32Version1.1July8,2005baseloadoraverageemissionfactorshouldbeusedratherthanthemarginalorpeakpoweremissionfactor.Wherecompaniescandemonstratethatapeakpoweremissionfactor(orsomeotheremissionfactor)ismoreappropriate,itcanbeused,butthejustificationshouldbenotedintheresults.Insomecases,theemissionfactorforpurchasedpowerwillreflectspecificpurchasingagreementswithapowersupplier(e.g.,for“green”power).IncaseswhereimportedpowerisgeneratedbyanearbyCHPsystem,theemissionsassociatedwiththeimportedpowercanbeestimatedusingthemethoddescribedinSection12.6.Ofcourse,ifamillisusingalloftheheatandpowerfromaCHPsystem,thereisnoneedtoallocatetheemissions.Insuchacase,ifthecompanyownsorcontrolsthesourcealltheemissionswillbereportedasdirectemissions.Ontheotherhand,ifthesourceisownedorcontrolledbyanotherentityalltheemissionswillbereportedasindirectemissions.Examplecalculation:Millpurchasingelectricalpower.AmillinAlberta,Canadapurchases300TJofelectricalpower(83,300MWh)inayear’stime.TheCanadianVCRRegistrationGuideshowsanaverageemissionfactorforpurchasedpowerinAlbertaof0.991kgCO2eq./kWh.Theindirectemissionsassociatedwiththepurchasedpowerareestimatedasfollows.•83,300MWh/y=83.3x106kWh/y•(83.3x106kWh/y)x(0.991kgCO2-eq./kWh)=82.6x106kgCO2-eq./y=82,600tCO2-eq./y12.3ElectricityExportsThesecalculationtoolssuggestaformatforreportingresultswhereinamillreportsalldirectemissionsassociatedwiththegenerationofpowerandsteam,whetherthepowerandsteamisusedinternallyorexported.Incircumstancesinwhichacompanywantstodelineatetheamountofdirectemissionsattributabletoexportedpowerandsteam,theexamplereportingtablesprovideasuggestedformat.Thetablesalsosuggestaformatforcompaniestocomparethecarbonintensityofexportedpower(inkgCO2/MWh)tothecarbonintensityofthepoweronthegridintowhichthepowerisexported.Companiesmayfindthishelpfulforhighlightingthebeneficialenvironmentalattributesofexportsofbiomass-basedpowerandpowerproducedbyCHPsystems.CompanieswantingtoconformtotheWRI/WBCSDGHGProtocolshouldnotnetimportsandexportsortheassociatedemissions.Electricityexportsmaybeincludedintheoptionalinformationcategory,butemissionsfromthecreationoftheelectricitywillstillbeincludedinthedirectemissionscategoryfortheorganization.Estimatingtheemissionsimpactofexportedpowerinvolvesestimatingtheemissionsgeneratedbythemilltoproducetheexportedpower.Becauseexportedelectricityfrommillsisusuallygeneratedincombinedheatandpower(CHP)systems,companieswilloftenneedtousethemethodsforCHPsystems(Section12.6)toestimatetheemissionsattributabletotheexportedpower.Version1.133July8,2005Intheinventoryresults,companiescanshowthecarbonintensityofexportedpowerorsteam(e.g.,inkgCO2/MWhorkgCO2/GJ)comparedtothecarbonintensityofthegridintowhichthepowerorsteamisexported.Toestimatethecarbonintensityofthegrid,themillshouldusethemostappropriategridemissionfactoravailable;i.e.,onethatreflectstheemissionsassumedtobedisplacedbythepowerbeingexported.Becausemillsusuallyexportpowerintobaseloads(i.e.,millsdonotusuallyserveassuppliersofpeakingpower),thebaseloademissionfactorwillbeusedinmostcasesratherthanthemarginalorpeakpoweremissionfactor.Companiesmayusethepeakormarginalemissionfactors,however,iftheyaremoreappropriate.12.4SteamImportsInmanycaseswheresteamisimportedbyamill,itisproducedbyanearbyCHPsystem.Inthesecases,theindirectemissionsreportedbythemillcanbeestimatedusingtheallocationmethoddescribedinSection12.6.Inothercases,thecontractualarrangementbetweenthemillandthesteamproducermaydefinehowtheemissionsfromthepowerplantaretobeallocatedbetweenthepowerandthesteamsoldbythepowerplant.Inthesecases,theallocationshouldbeexplainedintheresults.IftheimportedsteamisnotgeneratedinaCHPsystem,bestprofessionaljudgmentmustbeusedtoestimatetheemissionsreportedbythemill.Inthesecalculations,theheatdeliveredtothemillcanbeadjustedtoreflecttheamountofheatinreturnedcondensates.Themethodusedtoestimatetheindirectemissionsassociatedwithimportedsteamshouldbedescribedintheresultsoftheinventory.12.5SteamandHotWaterExportsAsinthecaseofelectricity,thetotalon-siteemissionsfromcompany-ownedboilersareshownasdirectemissionswhethersteamorhotwaterisexportedornot,buttheemissionsassociatedwithexportedsteamorhotwatercanbeshownseparately;forexample,intheGHGProtocolthisinformationcanbeprovidedintheoptionalinformationsection.Themethodforestimatingtheseemissionsisanalogoustothemethodusedforexportedelectricity.ThemethodusedtodeveloptheestimatewilldependonwhetheraCHPsystemisinvolved.IfsteamfromaboilerisexporteddirectlywithoutfirstbeingusedinaCHPsystem,theemissionsfromtheboilercanusuallybeallocatedindirectproportiontotheamountofsteamexported(asafractionofthetotalamountofsteamgeneratedbytheboiler).If,however,aCHPsystemisinvolved,themethoddescribedinSection12.6shouldbeusedtoallocateemissions.Ineithercase,theheatdeliveredbythemillcanbeadjustedtoreflecttheamountofheatinreturnedcondensates.Avarietyofsituationswillrequiretheuseofbestprofessionaljudgment.Exportsofhotwateraretreatedthesameasexportsofsteam,onanenergycontentbasis(i.e.,1GJofhotwaterenergyisassumedtobeequivalentto1GJofsteamenergy,thermallossesduringgenerationofhotwaterfrommill-generatedsteamareassumedtobenegligible).12.6AllocatingEmissionsfromCombinedHeatandPower(CHP)SystemsWhereelectricityisproducedbycombinedheatandpower(CHP)systems,itmaybenecessarytoallocatetheemissionsfromtheCHPsystemtothevariousoutputenergystreams.Ofcourse,ifthemillownstheCHPsystemandusesallofitsoutput,allocationis34Version1.1July8,2005notnecessarybecausealloftheemissionsaredirectemissionsforthemill.Inmanycases,however,amillmayeitherreceiveCHPenergyfromanoutsideproviderorexportaportionofitsownCHPoutput.Forinstance,ifamillisimportingsteamfromanearbypowerplant,itisnecessarytoestimatetheindirectemissionsassociatedwiththeimportedsteam.Likewise,ifamillisexportingpowerfromaCHPsystembutusingthesteaminternally,onemustestimatehowmuchofthemill’semissionsareattributabletotheexportedelectricity.Exportsofhotwateraretreatedthesameasexportsofsteam.AlthoughthereareseveralmethodsforallocatingemissionsfromCHPsystems,the“efficiency”methodisrecommendedinthesecalculationtools(additionalinformationonanumberofdifferentmethodsispresentedinAnnexB).Thismethodisrecommendedbecauseitattemptstorelateenergyoutputstotheamountsoffuelusedtogeneratethemand,byextension,totheGHGsproducedingeneratingthem.Whereacompanyusesanalternativemethod,themethodshouldbeexplainedintheresults.TheefficiencymethodisoneofthreemethodsrecommendedbyWRI/WBCSD(WRI2004b,c).Therearetwoversionsofthemethod.Thesimplifiedefficiencymethodislesscomplexbutinvolvesseveralassumptionsaboutequipmentefficiencies.Itisexpectedthatthesimplifiedmethodwillbeadequateformanymillsand,therefore,itisincludedinthisreportasadefaultmethod.Thedetailedefficiencymethodismorecomplicatedbutcanusesite-specificdesignandoperatingdatathatcompaniessometimeshaveforCHPsystems.ThedetailedefficiencymethodisdescribedinAnnexB.WhereamillorcompanyhasmorethanoneCHPsystem,itneednotallocatetheemissionsfromallsystemsusingthesameefficienciesforpowerandsteamgenerationifthereisabasisforusingdifferentefficienciesondifferentCHPsystems.12.6.1SimplifiedEfficiencyMethodTheefficiencymethodrequiresuseofassumedefficiencyfactorsfortheproductionofpowerandsteam,oractualefficiencyfactorsforeachsteamorpowergenerationdevicebasedondetailedprocessdesignandoperatinginformation.Itisassumedthattheefficiencyofproducinghotwateristhesameastheefficiencyofproducingsteam.Thesimplestapproachtoapplyingtheefficiencymethodistoassignasingleefficiencyfactortoallpoweroutputandasingleefficiencyfactortoallheat(steamandhotwater)output.Thisinformationisusedtocomputeanefficiencyratioequaltotheheatproductionefficiencydividedbythepowerproductionefficiency.Forexample,iftheCHPsystemproducessteamat80%efficiencyandpowerat40%efficiencytheratiois2.Theefficiencyratioisusedratherthantheindividualefficienciesbecause(a)itistheratiothatcontrolstheallocationofemissionsratherthantheindividualefficiencies,and(b)theindividualefficienciesareconstrainedbytheenergybalancesoitisnotpossibletospecifybothindependently.EmissionsfromtheCHPsystemareallocatedbetweentheheatandpoweroutputs,basedonthisratioofefficiencies,usingEquations5and6.Thisapproachisreferredtointhisreportasthesimplifiedefficiencymethod.Thesimplifiedefficiencymethodisrecommendedformillsthatlack,orchoosenottouse,detaileddesignandoperatingdatafromCHPsystems.Version1.135July8,2005PHeffTeffHeeRRPHHEE=⎪⎭⎪⎬⎫⎪⎩⎪⎨⎧×+×=;(Eq.5)where:EH=emissionsshareattributabletoheatproduction,tGHG/yET=totalemissionsfromtheCHPplant,tGHG/yH=heatoutput,GJ/yP=poweroutput,GJ/yReff=ratioofheatproductionefficiencytopowerproductionefficiencyeH=assumedefficiencyoftypicalheatproduction(default=0.8)eP=assumedefficiencyoftypicalelectricpowerproduction(default=0.35)Theemissionshareattributabletoelectricpowerproductionisassignedfromtherelation:HTPEEE−=(Eq.6)where:EP=emissionsshareattributabletoelectricpowerproductionInthesecalculations,theheatinsteamcanbecorrectedtoreflecttheamountofheatinreturnedcondensates.Inusingthesimplifiedefficiencymethod,efficienciesof0.35forpowergenerationand0.8forsteam(orhotwater)generationarerecommended,correspondingtoaratioofefficiencies(Reff)of2.3.Theexamplecalculationbelowmakesuseoftheserecommendeddefaultefficiencyfactors.ExampleCalculation:AllocatingCHPemissionstothreeoutputstreams–SimplifiedefficiencymethodwithWRI/WBCSDrecommendeddefaultefficiencyfactorsfortheUS.AmillhastheCHPsystemshowninthefollowingfigure,butitislacking(orchoosesnottouse)detailedenergybalanceinformation.Instead,thecompanychoosestousethesimplifiedefficiencymethodandthedefaultefficienciesrecommendedbyWRI/WBCSDfortheUS;0.35forpowergenerationand0.8forsteamgeneration(WRI2004b,c).HRSGFuel2974m3/hrnat.gasStm.TurbineP2=3MWH1=15MW19,500kg/hrsteam170°C,7barSteamHs=19.21MWGas-firedTurbineFuel11538m3/hrnat.gasHeatP1=5MWeffBUsingtheseassumedefficiencies,emissionscanbeallocatedamongthethreeoutputsoftheCHPsystemasfollows(usingabasisofonehourofoperation):36Version1.1July8,2005Totalsystememissions:Fuel1:CO2(1538m3/hr)x(0.039GJ/m3)x(55.9kgCO2/GJ)=3353kgCO2/hrCH4(1538m3/hr)x(0.039GJ/m3)x(0.0006kgCH4/GJ)x(21CO2-eq./CH4)=0.76kgCO2-eq./hrN2O(1538m3/hr)x(0.039GJ/m3)x(0.0001kgN2O/GJ)x(310CO2-eq./N2O)=1.86kgCO2-eq/hrTotalFuel1emissions=3356kgCO2-eq./hrFuel2:CO2(974m3/hr)x(0.039GJ/m3)x(55.9kgCO2/GJ)=2123kgCO2/hrCH4(974m3/hr)x(0.039GJ/m3)x(0.0014kgCH4/GJ)x(21CO2-eq./CH4)=1.12kgCO2-eq./hrN2O(974m3/hr)x(0.039GJ/m3)x(0.0001kgN2O/GJ)x(310CO2-eq./N2O)=1.18kgCO2-eq./hrTotalFuel2emissions=2126kgCO2-eq./hrTotalCHPsystememissions=3356+2126=5482kgCO2-eq./hrTotalsystempoweroutput=P1+P2=8MW3.235.08.0==effR()eqkgCOeqkgCOMW8MW115MWEH22462254823.25=××+=⎭⎬⎫⎩⎨⎧=20,681tCO2eq/yat350d/yoperationeqkgCOeqkgCOeqkgCOEP230202246225482=−==25,368tCO2eq/yrat350d/yoperationUsingthesimplifiedefficiencymethodwithdefaultpowerandsteamefficiencyfactors,therefore,theemissionsfromtheCHPsystemareallocatedtotheoutputstreamsinthefollowingpercentages:•PercentageofCHPemissionstoheatoutput=1002462/5482=44.9%•PercentageofCHPemissionstopoweroutput=1003020/5482=55.1%ThesepercentagescanbeusedtoallocateallGHGemissionsfromtheCHPsystem.Emissionfactorscanbedevelopedfortheenergyoutputs:•EmissionfactorforCHPheatoutput=(2462kgCO2-eq./hr)/15MW=164.1kgCO2-eq./MWh•EmissionfactorforCHPpoweroutput=(3020kgCO2-eq./hr)/8MW=377.5kgCO2-eq./MWhVersion1.137July8,200513.0GREENHOUSEGASEMISSIONSFROMVEHICLESANDMISCELLANEOUSFOSSILFUEL-FIREDEQUIPMENTCompaniesoftenownvehiclestotransportrawmaterials,products,wastes,andemployees.Companiesmayalsoownoff-roadvehiclesandothertypesoffossilfuel-firedequipment.BecausecompaniesmaywanttoincludetheseemissionsincorporateGHGinventories(asrecommendedintheWRI/WBCSDGHGProtocol),theyareaddressedinthesecalculationtools.Companiesshouldindicateintheresultsoftheinventorywhethertheseemissionshavebeenincluded.13.1GreenhouseGasEmissionsfromOn-RoadVehiclesCompanieswantingtoincludetheseemissionscanbasethemoneitherfuelconsumptionstatisticsorinformationondistancestraveled.IfcompaniesusefuelconsumptionstatisticstoestimateCO2emissions,theestimatesarederivedusingthesameapproachandemissionfactorsasusedforstationaryfossilfuelcombustionsources(Section8.1).EmissionfactorsforCH4andN2Oforon-roadsourcescanbefoundinIPCC1997c.AvarietyofparametersaffectCH4andN2Oemissionsfromon-roadvehicles,includingtypeofvehicle,fuelconsumed,operatingcharacteristics,emissioncontrols,maintenanceprocedures,andfleetage.Theimpactsoftheseparametersarereflectedinthetablesofemissionfactorsforon-roadvehiclesincludedinIPCC1997c.Ingeneral,CH4andN2Oemissionfactorsforgasoline-fueledon-roadvehicles,combinedandexpressedintermsofCO2-equivalents,rangefrom1.2to13.5kg/GJwithamedianvalueof4.6kg/GJ.Diesel-fueledsourcesareassociatedwithsomewhatlowerCH4andN2Oemissionfactors,whichrangefrom0.6to4.4kgCO2-equiv/GJ,withamedianvalueof1.0kgCO2-equiv/GJ.Forcontext,CO2emissionfactorsforliquidtransportationfuelsareusuallycloseto70kgCO2/GJ.TheemissionfactorsinIPCC1997cdemonstratethatforsometypesofon-roadtransportationsourcesCH4andN2OemissionsrepresentonlyasmallfractionofoverallGHGemissions,whereastheycanbemoresignificantforothertypesoftransportationsources.TheguidanceprovidedinWRI2004donlyaddressesCO2emissionsfromtransportationsources,presumablyduetothedifficultyinassessingCH4andN2OemissionsandthesmallcontributiontooverallGHGemissionstheyrepresentformanyofthesesources.Itshouldberecognizedthatuseofdistance-basedemissionfactorsmayresultinlessaccurateemissionestimatesthanthosecomputedbasedonactualfuelconsumptiondata.If,however,thecompanyfindsitmoreconvenienttodevelopemissionsestimatesfromstatisticsondistancetraveledtheCO2emissionfactorsinWRI2004d(reproducedinAnnexC)canbeused.TheWRI/WBCSDGHGProtocoldoesnotprovideCH4norN2Oemissionfactorsfortransportationsources.13.2GreenhouseGasEmissionsfromOff-RoadVehiclesandEquipmentCompaniesmayownoff-roadvehiclesandotherfossilfuel-poweredequipmentthattheywanttoincludeintheoperationalboundariesoftheinventory.Thesesourcesmightincludeeverythingfromforkliftstochainsaws.38Version1.1July8,2005FuelconsumptionstatisticscanbeusedtoestimateCO2emissionsfromthesesourcesusingtheemissionfactorsinTable2.CH4andN2OemissionscanbeanotablefractionoftheGHGemissionsfromsomeofthesesources.N2Oemissionsforsomeofthesesourcesarereportedtobenear30g/GJor9kgCO2-equiv./GJ,whichcanamounttomorethan10%oftheCO2emissionsfromsuchsources.Emissionfactorsformobilesourceshavebeenpublishedinanumberofplaces.SomeoftheavailableinformationissummarizedinAnnexC.IPCC’sguidelinescontainseveraldifferentsetsofemissionfactorswithoutrecommendingasingleset(IPCC1997c).Table9isfromoneofthesourcescitedbyIPCC.TheCO2factorsinthetablearefromTable2andareslightlydifferentthanthoseintheoriginaltableinIPCC1997cduetocorrectionforunoxidizedcarbon,usingtheIPCCrecommendations.Table9alsoincludesoverallCO2-equivalentemissionfactorsdevelopedusingtheIPCCglobalwarmingpotentialsforCH4(21)andN2O(310).ThepublishedemissionfactorsforCH4andN2Ofrommobilesourcesvaryfromoneprotocoltoanother.ThedifferencesinN2O,inparticular,canimpacttheCO2-equivalentsbyasmuchas10%.Wherecompaniesneedpreciseestimatesforthesesources,itisrecommendedthatthevarioussourcesdiscussedinAnnexCbeexaminedtodeterminewhichemissionfactorsaremostappropriate.Inmostcases,however,theemissionfactorsinTable9willbeadequate.Table9.EmissionFactorsforNon-RoadMobileSourcesandMachinery(IPCC1997c)(IPCCRevised1996GuidelinestakenfromEMEP/CORINAIR)SourceandEngineTypeCO2kg/TJCH4kg/TJN2Okg/TJCO2-equiv.kg/TJForestry–diesel73,40043082,800Industry–diesel73,40043082,800Railways–diesel73,40043082,800Inlandwaterway–diesel73,40043082,800Marine–diesel73,4007274,200Industry–gasoline4-stroke68,60050270,300Forestry–gasoline2-stroke68,6001700.472,300Industry–gasoline2-stroke68,6001300.471,500Inlandwaterway–gasoline4-stroke68,60040270,100Inlandwaterway–gasoline2-stroke68,6001100.471,000FromTable2,correctedforunburnedcarbonVersion1.139July8,2005Examplecalculation:GHGemissionsfromon-sitevehiclesandequipment.Basedonpurchasingrecords,amillestimatestheamountsoffuelpurchasedoverayeartofuelon-sitevehiclesandequipment.ItappliesthelargestoftheemissionfactorsshowninTable1andestimatesthattheemissionsaremuchlessthan0.5%ofthemill’semissions.Ratherthantryingtodevelopamoreaccurateestimate,themilldecidestoreportintheresultsonlythattheemissionsfromthissourcearenon-materialbecausetheyrepresentlessthan0.5%ofthetotalemissions.Examplecalculation:GHGemissionsfromacompany’sforestryoperationsandwoodtransportfleet.Acompany’sfuelpurchasingrecordsindicatethat,inayear,thefollowingamountsoffuelareconsumedbythecompany’swoodlandsoperationsanditsfleetoftrucksusedtotransportwoodtothemill:•Gasoline=10,000l–Thecompanyestimatesthatapproximately90%ofthisisusedin4-strokeenginesand10%isusedin2-strokeenginesinforestryequipment.•Diesel=200,000lTheheatcontentofthegasolineisestimatedtobe0.034GJ/landtheheatcontentofthedieselfuelis0.038GJ/l.ThecompanydecidestousetheCO2-equivalentemissionfactorsinTable9toestimateemissions.•Gasolineusedin4-strokeengines=10,000l/yx0.9=9,000l/y•9,000l/yx0.034GJ/liter=306GJ/y=0.306TJ/y•0.306TJ/yx70,300kgCO2-equiv./TJ=21,500kgCO2-equiv./y=21.5tCO2-equiv./y•Gasolineusedin2-strokeengines=10,000l/yx0.1=1,000l/y•1,000l/yx0.034GJ/liter=34GJ/y=0.034TJ/y•0.034TJ/yx72,300kgCO2-equiv./TJ=2460kgCO2-equiv/y=2.5tCO2-equiv./y•Dieselused=200,000l/y•200,000l/y0.038GJ/l=7600GJ/y=7.6TJ/y•7.6TJ/yx82,800kgCO2-equiv./TJ=629,000kgCO2-equiv./y=629tCO2-equiv./yTotalGHGemissionsfromcompany-ownedforestryoperationsandwoodtrucks•21.5+2.5+629=653tCO2-equiv./y14.0GREENHOUSEGASEMISSIONSFROMWASTEINLANDFILLSThesecalculationtoolshavebeendevelopedassumingthatmanycompanieswillincludecompany-ownedlandfillswithintheinventoryboundaries.Thesetoolscanalsobeusedincaseswhereamill’sprocesswasteisbeingdisposedinamunicipalsolidwastelandfillandthecompanyisinterestedinestimatingthemill’scontributiontothemunicipallandfillemissions.Somecompaniesmaintainunmanagedpilesofwoodresiduals.Forwoodresidualpilesthatarenotintentionallycompostedorotherwiseaerated,methaneemissionscanbeestimatedusingthemethodsforlandfillsdescribedinSections14.2.1and14.2.2.40Version1.1July8,2005Asisthecasewithmostwidelyacceptedprotocols,onlyCH4emissionsareaddressedinthesetoolsbecauseCO2fromlandfillsiscomposedofbiomasscarbonandN2Oemissionsareassumedtobenegligible.AnemissionfactorforlandfilledwastewaspresentedinTable1.Thisfactorisbasedonanumberofconservativeassumptionsand,inmostcases,isexpectedtoproduceestimatesthatarehigherthantheactualemissionsattributabletolandfilledmillwaste.Theemissionfactorcanbeusefulindecidingwhetherlandfillemissionsarematerialtotheresultsoftheinventory.Themethodsdescribedherein,however,arerecommendedforpreparinganestimatetouseintheinventoryresults.14.1UsingDatafromLandfillGasCollectionSystemsInsomecases,companylandfillsarecappedwithlowpermeabilitycovermaterialandthelandfillgasesarecollected.Inmanyofthesesituations,theamountsofmethanecollectedanddestroyedcanbeestimatedfromsite-specificdata.IPCC’srecommendedapproachusesthisinformationonlyindirectly.IPCCrecommendsthatcompaniesestimatelandfillgasemissionsbyfirstestimatingtotalgasgeneration(usingoneofseveralmathematicalmodelsdiscussedbelow)andthensubtractingtheamountsofmethanecapturedandburned.Thedifferencebetweenthetwoisassumedtobeemitted.Theproblemwiththisapproachisthat,becauseofthelargeuncertaintiesinestimatingmethanegeneration,theamountsburnedcouldeasilybegreaterthantheamountsthecompanyestimatesweregenerated,resultinginanegativerelease.Itisequallypossiblethatthecomparisonofestimatedgenerationratestomeasuredcollectionratescouldsuggestimpossiblylowcollectionefficiencies,duesolelytotheuncertaintiesinestimatingmethanegeneration.Analternativeapproachisavailabletocompaniesthatmeasuretheamountsofmethanecapturedinefficientcollectionsystems:toestimatethecollectionefficiencyofthesystemandthenbackcalculatetheamountsofmethanegenerated.Forinstance,ifamillwithacappedlandfillhasdeterminedthatitscollectionsystemcollects90tonsofmethaneperyearandthemillestimatesthatthecollectionefficiencyis90%,100tonsofmethaneweregenerated.Theproblemwiththisapproachisthattheeffectivenessoflandfillgascollectionsystemsisvariableanduncertain.Reportedcollectionefficienciesrangefrom60to85%(USEPA1998d).ThisvariabilityanduncertaintyhascausedIPCCtotakethepositionthat“theuseofundocumentedestimatesoflandfillgasrecoverypotentialisnotappropriate,assuchestimatestendtooverestimatetheamountofrecovery”(IPCC2000a).Nonetheless,thisapproachisbuiltaroundameasuredvalue–theamountofgascollected.Forthisreason,itisreasonabletoexpectthatinsomecases,ifnotmany,itwillyieldmoreaccurateestimatesthanIPCC’sdefaultmethodology.ThisisespeciallytrueformilllandfillsbecauseofthelimiteddataavailableforderivingtheparametervaluesneededtouseIPCC’smathematicalmodelsforestimatingemissions.Therefore,inthesecalculationtoolsitisrecommendedthatwherecompany-ownedlandfillsarecoveredwithlowpermeabilitycapsandequippedwithlandfillgascollectionsystemsthatareconstructedandoperatedtonormalstandards,themethanegenerationratesshouldbeVersion1.141July8,2005backcalculatedfrom(a)measurementsoftheamountsofmethanecollected;and(b)measuredorassumedcollectionefficiency.Adefaultcollectionefficiencyof75%hasbeenusedbysomeauthoritiesandisrecommendedhereunlesssite-specificcollectionefficiencydataareavailable(USEPA1998d).ThesecalculationtoolsalsoassumethatallofthemethanethatiscapturedandburnedisconvertedtobiomassCO2andthereforeisnotincludedinGHGtotals.Usingthesedefaultvaluesandassumptions,estimatesofmethanereleasescanbedevelopedusingEquation7.CH4(m3/y)releasedtotheatmosphere=[(REC/FRCOLL)(1–FRCOLL)FRMETH(1–OX)]+[RECFRMETH(1–FRBURN)](Eq.7)where:REC=amountoflandfillgascollected,determinedonasite-specificbasis,m3/yFRCOLL=fractionofgeneratedlandfillgasthatiscollected,defaultis0.75FRMETH=fractionofmethaneinlandfillgas,defaultis0.5OX=fractionofmethaneoxidizedinthesurfacelayerofthelandfill,defaultis0.1FRBURN=fractionofcollectedmethanethatisburned,site-specificdetermination14.2EstimatingMethaneEmissionsatLandfillswithoutGasCollectionData14.2.1SimplifiedFirstOrderDecayApproachWheretheapproachdescribedinSection14.1cannotbeused,itisrecommendedthatcompaniesemploythefirstorderdecaymodelapproachforestimatinglandfillgasemissionsusingparametervaluesderivedforpulpandpapermilllandfills.ThisapproachisthedefaultmethodrecommendedbyIPCCandisusedbyanumberofnationalauthorities(IPCC2000a).ItcanbeusedtoestimateCH4emissionsfromactiveandinactivelandfills.Incaseswheretheannualdepositsare(orareassumedtobe)constantIPCC’sdefaultmethodreducestotwoequations.Thissimplifiedapproachshouldbeadequateunlesstheamountsortypesofwastebeinglandfilledhavechangedsignificantlyfromyeartoyear(e.g.,anewdeinkingmillisbuilton-site)orthelandfilldesignoroperationhasbeenchangedinawaythatwouldsignificantlyimpactmethanegenerationorrelease(e.g.,agascollectionsystemisinstalled).Thesimplifiedapproachisasfollows.CH4(m3/y)generatedfromallwasteinthelandfill=RL0(e-kC-e-kT)(Eq.8)where:R=averageamountofwastesenttolandfillperyear,Mg/yL0=ultimatemethanegenerationpotential,m3/Mgwastek=methanegenerationrateconstant,1/yC=timesincelandfillstoppedreceivingwaste,yT=yearssincelandfillopened,y(Note:RandL0canbeinunitsofwetweight,dryweight,degradableorganiccarbon,orotherunitsbuttheunitsforRandL0mustbethesame.)42Version1.1July8,2005Wherecompaniescanseparatethequantitiesofinertwastes(e.g.,boilerash,concrete)itisrecommendedthatthesequantitiesnotbeincludedintheinputparameterR(averageamountofwastesenttothelandfilleachyear).Notallmethanethatisgeneratedissubsequentlyreleasedtotheatmosphere.Toestimateatmosphericreleases,usetheresultfromEquation8inEquation9.Forlandfillswithmoderngascollectionandcombustionsystemsbutnomeasurementsofquantitiesofgascollected,theamountofmethanerecoveredcanbeassumedtobe75%ofthatgenerated(USEPA1998d).CH4(m3/y)released=[(CH4generated–CH4recovered)(1–OX)]+[CH4recovered(1-FRBURN)](Eq.9)where:CH4generated=fromEquation8CH4recovered=amountofmethanecollected,site-specificdeterminationOX=fractionoxidizedinthesurfacelayerofthelandfillbeforeescaping,usuallyassumedtobe0.1FRBURN=fractionofcollectedmethanethatisburned,site-specificdeterminationIftheamountsbeinglandfilledhavechangedsignificantlyorifthelandfilldesignhasbeenalteredsothatsomeoftheparametervalueswouldhavechangedsubstantiallyovertime,amoreinvolvedapproachmaybeneeded.Todealwiththesemorecomplicatedsituations,manyprotocolsrecommendmodelingthegasgeneratedannuallyfromeachyear’sdepositsandsummingtheamountsthatarepredictedtooccurinthecurrentyear.ThismoredetailedanalysisisdescribedinSection14.2.2.AnnexDidentifiesanumberofsourcesfortheparametervaluesL0andkneededinEquation8.Unfortunately,thevaluesvaryconsiderablyfromoneprotocoltothenextandarebasedonveryfewdata.Forsituationswherepulpandpapermillwastewatertreatmentsludgearemajorconstituentsofthewaste,reasonablevaluesfortherateconstant,k,fallintherangeof0.01/yrto0.1/yr,whilethoseforL0fallbetween50and200m3/Mg.ResearchiscurrentlyunderwayintheUSthatshouldhelpnarrowtheseranges.Initialindicationsarethattheamountsofgasgeneratedinforestproductsindustrylandfillsarelessthanwouldbepredictedusingparametervaluesdevelopedformunicipalsolidwaste(NCASI1999).Withthisknowledge,itisrecommendedthatuntilthecurrentresearchiscompleted,andunlesscompanieshavecountry-specificorsite-specificfactorsthataremoreappropriatefortheirwastes,companiesshouldusetheparametervaluesshowninTable10.AnnexDcanbereferredtoforadditionalinformationonthederivationofthedefaultparametersshowninTable10.Table10.RecommendedDefaultValuesforkandL0forEstimatingLandfillMethaneEmissionsParameterDefaultValuek0.03y-1L0100m3/MgdryweightofwasteVersion1.143July8,200514.2.2DetailedFirstOrderDecayApproachToallowyear-to-yearvariationsintheamountsofwastesenttoalandfill,IPCCsuggestsavariationofthisapproach.Startinginyearone,calculatehowmuchmethanewillbegeneratedineachsubsequentyearbywastedepositedinthatyearusingEquations10and11.CH4generatedinagivenyearbywastedepositedinanearlieryear(m3/y)=kRyL0(e-k[T-Y])(Eq.10)wherek=methanegenerationrateconstant,1/yrRY,=theamountofwastesenttolandfillinyearY,Mg/yrL0,=ultimatemethanegenerationpotential,m3/MgwasteT=yearforwhichemissionsarebeingestimated,givenintermsofyearssincethelandfillopenedY=yearafterlandfillopenedthatwastewasdisposedThus(T-Y)isequaltothenumberofyearsthewastehasbeeninplacepriortotheyearforwhichemissionsarebeingestimated.CH4(m3/y)released=[(CH4generated–CH4recovered)(1–OX)]+[CH4recovered(1-FRBURN)](Eq.11)where:CH4generated=fromEquation10CH4recovered=amountofmethanecollected,site-specificdeterminationOX=fractionoxidizedinthesurfacelayerofthelandfillbeforeescaping,usuallyassumedtobe0.1FRBURN=fractionofcollectedmethanethatisburned,site-specificdeterminationWherecompaniescanestimatethequantitiesofinertwastesseparately(e.g.,boilerash,concrete)itisrecommendedthatthesequantitiesnotbeincludedintheinputparameterRY(amountofwastesenttothelandfillinyearY).Thecalculationsareperformedbyestimatinghowmuchwastewasdepositedeveryyearsincethelandfillwasopened.IPCCindicatesthatforveryoldlandfillsitispossibletolimittheretrospectiveperiodtoonestartingatleastthreewastedegradationhalf-livesbeforethecurrentyear.Giventheslowdegradationobservedinmanymillsludges,25yearsisprobablytheminimumthatwouldsatisfythiscriterion.Foreachyear’sdeposit,theamountofmethanereleasedthatyearandeachfollowingyearisestimated.Insubsequentyears,theamountofmethanereleasedisthesumoftheamountsestimatedfromeachprioryear’sdepositsthatwereprojectedtooccurinthatyear.Inyear1,amountAisdepositedanditisestimatedthatinyears1,2,3,…itwillreleaseX1,X2,X3,…tonsofmethane,respectively.Thereportedemissionsforyear1areX1tonsofmethane.Inyear2,amountBisdepositedanditisestimatedthatinyears2,3,4,…itwillreleaseY2,Y3,Y4,…tonsofmethane,respectively.Theemissionsreportedforyear2areX2plusY2tonsmethane.Inyear3,amountCisdepositedanditisestimatedthatinyears3,4,5,…itwillreleaseZ3,Z4,Z5,…tonsofmethane,respectively.Thereportedemissionsforyear3areX3plusY3plusZ3tonsofmethane.Thisprocessrepeatsitselfeveryyear.44Version1.1July8,2005ThevaluesforkandL0arethesameasthoseusedinthesimplifiedfirstorderapproach,aspresentedinTable10.ExampleCalculation:Emissionsfromamilllandfillwithamodernlow-permeabilitycapandgascollectionsystem.Thecollectedgasisburned.Measurementshavebeenmadeonalandfillgascollectionsystem.Thesystemiscollecting820,000standardm3/yandthegasis47%methanebyvolume.Themillhasnosite-specificdataontheefficiencyofthegascollectionsystem,soitusestherecommendeddefaultvalueof75%.Italsousesthedefaultassumptionthat10%oftheuncollectedgasisoxidizedbeforeescapingtotheatmosphere.•methanecollected=820,000m3/yx0.47=385,000m3/y•methanegenerated=(385,000m3/y)/0.75=513,000m3/y•methanereleased=(513,000–385,000)m3/yx(1-0.1)=115,000m3/y=115x106l/y•methanereleased=(115x106l/y)/22.4l/g-mole=5.13x106g-mole/y•methanereleased=(5.13x106g-mole/y)x16g/g-mole=82x106g/y=82tCH4/yUsingtheIPCCGWP(21),thisisequalto1720tCO2-equiv./yExamplecalculation:Emissionsfrom20yearoldlandfillreceivingmillwastewatertreatmentsolidsandash.Thelandfilldoesnothaveagascollectionsystem.Amilllandfills50tonperdayofsolidwastecomposedprimarilyofwastewatertreatmentplantsolids,ash,andothermiscellaneouswastetypicalofakraftmill.Themillgenerateswaste350daysayear.Thelandfillhasbeeninusefor20yearsandisstillactive.Thelandfilldoesnothaveagasrecoverysystem.ThemillusesthedefaultvaluesforkandL0showninTable10(100m3/MgforL0and0.03y-1fork).R=50Mg/dx350d/y=17500Mg/yL0=100m3/Mgk=0.03/yC=0yT=20y•methanegenerated(m3/y)=17,500x100x(e-0.03x0–e-0.03x20)=790,000m3/y•densityofmethane(0oCand1atm.pressure)=0.72kg/m3(fromPerry’sChemicalEngineers’Handbook)•methanegenerated(kg/y)=790,000m3/yx0.72kg/m3=568,000kg/y=568t/y•assume10%oxidationinlandfillcover•methanereleased=568t/yx(1–0.1)=511tCH4/yreleasedUsingtheIPCCGWP(21),thisequals10,700tCO2-equiv./yNotethattheTable1emissionfactorwouldhaveyieldedanestimateof50t/dx350d/yx3,500kg/t=61,250,000kg/y=61,250tCO2-equiv./y,overfivetimestheestimatedevelopedusingthemorerefinedapproach.Version1.145July8,200515.0GREENHOUSEGASEMISSIONSFROMANAEROBICTREATMENTOFWASTEWATERORSLUDGEMostexistingGHGprotocolsaddresswastetreatmentplantemissionsonlyfromanaerobictreatmentanddigestionprocesses.Therefore,thesecalculationtoolshavebeendevelopedassumingthatemissionsfromothertypesofwastewaterandsludgetreatmentprocessesarenegligible.Althoughaerobicandfacultativetreatmentsystemsmayhavezoneswithdepleteddissolvedoxygen,methanegenerationratesinaeratedstabilizationbasins,activatedsludgesystems,andtheirassociatedretentionpondswouldbeexpectedtobemuchlowerthanthoseestimatedforanaerobicsystems.Inanyevent,duetolackofdata,emissionsfromaerobicandfacultativetreatmentoperationsareseldomestimated.IPCC,forinstance,recommendsadefaultassumptionthatamethaneconversionfactorofzerobeusedforaerobicsystems(IPCC1997c).Evenforanaerobicsystems,onlyCH4emissionsneedtobeestimated.TheCH4emissionsfromcompany-ownedanaerobicsystemswillbereportedasdirectemissions.TheCO2emittedfromwastewaterandsludgetreatmentoperationscontainsbiomasscarbonwhichisnotincludedinGHGtotals.WherethisbiomassCO2isnotcombustionrelated(e.g.,itisnotformedfromcombustionofmethane),itisoftenexcludedfrominventoryresultsaltogether.Inaddition,N2Oemissionsfromtreatmentplantshavebeenfoundtobesmall,andprobablyoccuronlyafterthewastewaterisdischarged(IPCC1997c).15.1AnaerobicTreatmentOperationswhereOff-GasesareCapturedInmanycases,anaerobictreatmentsystemsarecoveredandthegasesarecollectedandburned.Oneofthepurposesofthesecollectionsystemsisthepreventionofodors,andtoaccomplishthisobjectivethesystemsmustbehighlyefficient.ForpurposesofaGHGinventoryitisreasonabletoassume,therefore,thatwheremethaneemissionsfromanaerobictreatmentoperationsarecapturedandburned,thecollectionanddestructioniscompleteandnomethaneisemitted.BecausetheCO2producedinburningtheCH4containsbiomasscarbon,itdoesnotneedtobereportedinGHGinventorytotals.Ifcircumstancesatamillsuggestthatnon-trivialamountsofmethaneareescapingcollection,themillmayneedtoundertakeeffortstoaccountforthesereleases,butsuchcircumstancesareexpectedtobeunusualatmillsthatcollectandburnthesegases.Ofcourse,ifthegasesarecollectedbutreleasedtotheatmosphereratherthanbeingburned,theyshouldbeincludedintheinventory.15.2AnaerobicTreatmentOperationswhereOff-GasesareReleasedtotheAtmosphereWhereoff-gasesfromanaerobictreatmentoperationsarenotcollectedandburned,itisnecessarytoestimatethereleasesofmethanetotheatmosphere.Insomecases,forinstancewherethegasesarereleasedthroughaventinacoveredvessel,thereleasescanbemeasureddirectly.Inmostothercases,theymustbeestimated.ThesecalculationtoolssuggesttheuseoftheIPCCdefaultmethodologydescribedintheMay2000GoodPracticesdocumentandshowninEquation12(IPCC2000a).Althoughthe46Version1.1July8,2005IPCCdocumentallowstheequationtobeappliedtosystemsthatarenotcompletelyanaerobic(bymultiplyingtheresultbyanarbitraryadjustmentfactoroflessthanone),therearenodatacurrentlyavailabletosupporttheselectionoftheadjustmentfactor.Itisrecommended,therefore,thatmethaneemissionsbeestimatedonlyfromanaerobictreatmentorsludgedigestionsystemsuntilfactorsforothertypesofsystemsareavailable.AnaerobicTreatmentPlantMethaneEmissions(kg/y)=(OCxEF)–B(Eq.12)where:OC=BODorCODofthefeedtotheanaerobicsystem,kg/yearEF=emissionfactor,defaultvalues=0.25kgCH4/kgCODinthefeedor0.6kgCH4/kgBODinthefeed(oranotherBOD-basedfactordevelopedbymultiplyingtheCOD-basedfactorof0.25kgCH4/kgCODbythesite-specificCOD/BODratio)B=methanecapturedandburned,kgCH4/year,determinedonasite-specificbasisIfthesolidsarehandledseparately,emissionsfromsludgedigestionwouldbecalculatedusingEquation13.Incaseswheresludgeisburned,itisincludedinthecalculationsforGHGemissionsfrombiomassburningdiscussedinSection11.AnaerobicSludgeDigestionPlantMethaneEmissions(kg/y)=(OCsxEFs)-B(Eq.13)where:OCs=organiccontentofthesludgeEFs=emissionfactor,inunitsconsistentwithOCs-IPCC’sdefaultvalueis0.25kgCH4/kgCODinthesludgefeedB=methanecapturedandburned,kgCH4/yr,determinedonasite-specificbasisExamplecalculation:Recycledpaperboardmillwithanaerobictreatmentbutnogasrecovery.Arecycledpaperboardmillusesananaerobictreatmentplanttotreatwastewatercontaining10,000kgCOD/d.Themillgenerateswastewater300daysperyear.TheIPCCdefaultvalueforCH4generationfromanaerobictreatmentsystemsis0.25kgCH4/kgCODinthefeed.TheCH4emissionsarecalculatedasfollows.•OC=10,000kg/dx300d/y=3,000,000kgCOD/y•CH4generated=3,000,000kgCOD/yx0.25kgCH4/kgCOD=750,000kgCH4/y=750tCH4/yUsingtheIPCCGWP(21),thisequals15,750tCO2-equiv./y16.0PRESENTINGTHERESULTSOFTHEINVENTORYThesecalculationtoolsprovideanexampleformatforsummarizinginventoryresults.Companiesmayfindotherformatsmoreconvenientorappropriate,however,andarefreetochoosetheformatbestsuitedtotheirneeds.Itisimportantthattheoutputfromusingthesecalculationtoolsbe(a)disaggregatedtotheextentpossibletoensuretransparency;and(b)accompaniedbykeyinformationneededtointerprettheresults.Version1.147July8,2005Fourtablesthatcompaniesmayusetopresenttheresultsoftheinventoryarepresentedinthefollowingpages.Table11providesaformatfordescribingtheoperationsthathavebeenincludedwithintheoperationalinventoryboundaries.Companiesareencouragedtoincludeanyadditionalinformationthatwillhelpexplaintheboundariesortheresultsoftheinventory.Table12containsanexampleformatthatcanbeusedforrecordingdirectemissions.Theseareemissionswithintheboundariesoftheinventoryfromsourcesownedorcontrolledbythecompany.Thecompanyisfreetoselectamethodtodetermineownershipofemissionsfromsourcesonlypartlyownedorcontrolledbythecompany,butthemethodshouldbedescribedinthepresentationofresults.Alsointhistableisanexampleformatforincludinginformationregardingdirectemissionswhichareassociatedwithelectricityorsteamthatissoldtoanotherentity.Companiesareencouragedtousethisorasimilarformattocharacterizetheimpactofelectricityandsteamexports,whichcanhaveasignificantimpactonafacility’sgreenhousegasprofileTable13isasuggestedformatforrecordingindirectemissions(i.e.,emissionsfromsourceswithintheoperationalboundariesoftheinventorybutownedbyanotherentity),suchasemissionsattributabletoimportsofpowerandsteamandimportsandexportsoffossilfuel-derivedCO2.Companiesareencouragedtousethisorasimilarformattocharacterizetheimpactofoutsourcedoperations(powerislandsinparticular)thathaveasignificantimpactonafacility’sgreenhousegasprofile.Table14providesanexampleofaformatthatcanbeusedforrecordingtheemissionfactorsusedtopreparetheinventory.Companiesareencouragedtoincludethisinformationtomaketheresultsoftheinventorymoretransparent.Tables15through18illustratetheuseofthereportingtablesonanexamplemillinventory.TheschematicpresentedinFigure1illustratesthevarioussourcesandcategoriesofemissionswhichmaybeincludedinanemissionsinventory.CompanieswantingtopreparereportsthatmeettherequirementsoftheWRI/WBCSDGHGProtocolwillalsoneedtoreportreleasesofCO2frombiomasscombustion,separatefromdirectGHGemissions.AnnexEincludestables(TablesE1andE2)thatcanbeusedforthispurpose.AnExcel®workbookthatperformsthecalculationsdescribedinthisreportisavailable.Thecompletedworkbookrepresentsyetanotherwaytoconveytheresultsoftheinventory.48Version1.1July8,2005Table11.ExampleofaTabletoReportOperationalBoundariesoftheInventoryThismatrixmaybeusedtoindicatewhichoperationsareincludedwithintheboundariesoftheinventoryandtheirownership.Provideageneraldescriptionoftheboundaries,anyadditionalinformationneededtoexplainthemandthenputan“X”inappropriateboxes.Usethisspacetoprovideadditionalinformationhelpfultounderstandingtheoperationalboundariesoftheinventory,includingthemethodusedtoallocateemissionsfrompartly-ownedorpartly-controlledsources.Attachadditionalpagesifneeded.MarktoidentifyoperationsincludedintheinventoryHarvestingWood/chip/bark/wastepaper/otherrawmaterialtransportationvehiclesProduct,by-productorwastetransportationvehiclesDebarkingChippingMechanicalpulpingChemicalpulping–kraftChemicalpulping–sulfiteChemicalpulping–otherSemichemicalpulpingRecoveryfurnace–kraftLiquorfurnace–sulfiteLiquorfurnace–semichemLimekilnorcalcinerIncineratorsfornon-condensablegases,etc.WastepaperpulpingandcleaningDeinkingBleachingofchemicalorsemichemicalpulpBrighteningofdeinkedpulpOn-sitepreparationofchemicals(e.g.,ClO2orO3)Paperand/orpaperboardproductionCoating(includingextrusioncoating)Rolltrimming,rollwrapping,sheetcuttingOn-sitepowerandsteamboilersOn-sitecombustionturbinesGas-firedinfrareddryersOtherfossilfuel-fireddryersWastewatertreatmentoperationsSludgeprocessingLandfillreceivingmillwasteAiremissionscontroldevicesOn-roadvehiclesOff-roadvehiclesandmachineryNormaloffices/workspaceformillemployeesOtherOperation–describe:OtherOperation–describe:OtherOperation–describe:Version1.149July8,2005Table12.ExampleofaTabletoReportGHGInventoryResults–DirectEmissionsemissionsfromsourcesthatarewhollyorpartiallyownedorcontrolledbythecompanyTotalDirectEmissionsmetrictonsWhereemissionshavebeendeterminedtobeinsignificantornon-material,write“NM”andexplainthebasisforthedeterminationinafootnote.CO2CH4N2OCO2Equiv1ProcessandEnergy-RelatedEmissions1StationaryFossilFuelCombustion2BiomassCombustionN/A3Make-upChemicals(CaCO3andNa2CO3)Transportationandmachineryemissions4On-roadvehicles5Off-roadvehiclesandmachineryWastemanagementemissions6LandfillemissionsfrommillwastesN/A7AnaerobicwastewatertreatmentsystemsN/A8OtherDirectEmissionsnotincludedabove–Explain:TotalDirectEmissions(Sumoflines1through8)Emissionsassociatedwithexportedelectricityandsteam(asubsetoftotaldirectemissions)9EmissionsrelatedtoelectricityexportsCarbonintensityofelectricityexports(lbCO2/MWh)Carbonintensityofgridreceivingelectricityexports(lbCO2/MWh)MethodusedtoestimateGHGintensityofgrid:10Emissionsrelatedtosteamexports11Totalemissionsattributabletoexports(Sumoflines9and10)Explainthemethodusedtodetermineownership/controlofsourcesnotcompletelyownedbythecompany.AprotocolsuchastheWRI/WBCSDGHGProtocolcanbeusedforguidanceondeterminingownership/control.Includeanyotherinformationthatisneededtounderstandtheinventoryresults:1CO2-equivalentsarecalculatedmultiplyingindividualgasesbyIPCCGWPvalues,CO2=1,CH4=21,N2O=310,andsummingacrossallthreegases.ItisacceptabletouseemissionfactorsforCO2-equivalentsratherthanestimatingthethreegasesindividually.N/A–NotApplicable-carbondioxideemissionsfrombiomassarenotincludedinGHGtotalsbecausethiscarbonisconsideredpartofthenaturalcycle;i.e.,itisrecycledbetweentheatmosphereandplanttissue.50Version1.1July8,2005Table13.ExampleofaTabletoReportGHGInventoryResults–IndirectEmissionsemissionsattributabletopower/steamimports,andimports/exportsoffossil-CO2MetrictonsWhereemissionshavebeendeterminedtobeinsignificantornon-material,write“NM”andexplainthebasisforthedeterminationinafootnote.CO2CH4N2OCO2Equiv1Indirectemissionsrelatedtoelectricityandsteamimports,includingthosefromoutsourcedpowerislands1IndirectEmissionsrelatedtoelectricityimportsthatareconsumed2IndirectEmissionsrelatedtosteamimportsthatareconsumed3Totalindirectemissionsfrompower/steamimports(Sumoflines1through2)OtherIndirectEmissions4Descriptionofotherindirectemissionsincludedininventory:ImportsandExportsoffossilfuel-derivedCO25ImportsofCO2(e.g.,forneutralization)6Exportsoffossilfuel-derivedCO2(e.g.,toPCCPlants)Note1:ThisincludesonlythefractionofCO2exportsthatcanbetracedtofossilfuels.Exportsofbiomass-derivedCO2arereportedinAnnexE–SupportingInformationonBiomass.Note2:ThisexportedCO2shouldnotbereportedasanemissioninTable12.Explainthemethodusedtodetermineownership/controlofsourcesnotcompletelyownedbythecompany.AprotocolsuchastheWRI/WBCSDGHGProtocolcanbeusedforguidanceondeterminingownership/control.Includeanyotherinformationneededtounderstandtheinventoryresults:1CO2-equivalentsarecalculatedmultiplyingindividualgasesbyIPCCGWPvalues,CO2=1,CH4=21,N2O=310,andsummingacrossallthreegases.ItisacceptabletouseemissionfactorsforCO2-equivalentsratherthanestimatingthethreegasesindividuallyVersion1.151July8,2005Table14.ExampleofaTabletoReportEmissionFactors(EF)UsedtoPreparetheInventory(showunits)CO2CH4N2OCO2EquivSourceofEFFossilFuelCombustionFuelCombustionUnitsBiomassCombustionFuelCombustionUnitsN/AN/AN/AN/AN/AN/AN/AWasteManagementLandfill1emissions:%ofGasCollected=“k”=“L0”=Landfill2emissions:%ofGasCollected=“k”=“L0”=Landfill3emissions:%ofGasCollected=“k”=“L0”=AnaerobicTreatmentemissions:“EF”=ElectricalPowerandSteamImportsEmissionsfactorsforimportedelectricityEmissionfactorsforimportedsteamN/A–NotApplicable-carbondioxideemissionsfrombiomassarenotincludedinGHGtotalsbecausethiscarbonisconsideredpartofthenaturalcycle;i.e.,itisrecycledbetweentheatmosphereandplanttissue.52Version1.1July8,2005Table15.ExampleGHGInventoryResults–OperationalBoundariesoftheInventoryThismatrixmaybeusedtoindicatewhichoperationsareincludedwithintheboundariesoftheinventoryandtheirownership.Provideageneraldescriptionoftheboundaries,anyadditionalinformationneededtoexplainthemandthenputan“X”inappropriateboxes.Usethisspacetoprovideadditionalinformationhelpfultounderstandingtheoperationalboundariesoftheinventory,includingthemethodusedtoallocateemissionsfrompartly-ownedorpartly-controlledsources.Attachadditionalpagesifneeded.Smallamountsofpurchasedpowerforathirdpartywastepapersortingoperationareincludedinthemill’sinventoryresults.Also,anon-sitegasturbineCHPsystemownedbyanothercompanysuppliesthemillwithpowerandsteam,butmuchofthepowerfromthesystemissold.Theemissionsareallocatedusingthesimplifiedefficiencymethod.Whenthemillisdown,wesometimescontinuetogeneratebiomasspowerinmill-ownedcondensingturbinesandsellittothegrid.MarktoidentifyoperationsincludedintheinventoryHarvestingXWood/chip/bark/wastepaper/otherrawmaterialtransportationvehiclesXProduct,by-productorwastetransportationvehiclesDebarkingXChippingXMechanicalpulpingChemicalpulping–kraftXChemicalpulping–sulfiteChemicalpulping–otherSemichemicalpulpingRecoveryfurnace–kraftXLiquorfurnace–sulfiteLiquorfurnace–semichemLimekilnorcalcinerIncineratorsfornon-condensablegases,etc.XWastepaperpulpingandcleaningXDeinkingXBleachingofchemicalorsemichemicalpulpXBrighteningofdeinkedpulpXOn-sitepreparationofchemicals(e.g.,ClO2orO3)XPaperand/orpaperboardproductionXCoating(includingextrusioncoating)XRolltrimming,rollwrapping,sheetcuttingXOn-sitepowerandsteamboilersXOn-sitecombustionturbinesGas-firedinfrareddryersXOtherfossilfuel-fireddryersXWastewatertreatmentoperationsXSludgeprocessingXLandfillreceivingmillwasteXAiremissionscontroldevicesXOn-roadvehiclesXOff-roadvehiclesandmachineryXNormaloffices/workspaceformillemployeesXOtherOperation–describe:OnsitecommercialwastepapercollectionandsortingoperationOtherOperation–describe:OtherOperation–describe:Version1.153July8,2005DirectEmissionsEmissionsfromlandfillCH4LimeKilnEmissionsofCO2fromfossilfuel,CH4,andN2OCO2frommake-upcarbonatesusedinthepulpmillCO2Company-ownedon-siteboilers,vehiclesandequipmentthatuseonlyfossilfuelsCO2,CH4,andN2OCompany-ownedoff-sitevehiclesandequipmentthatusefossilfuelsCO2,CH4,andN2OOff-siteproductionofpurchasedpowerfromfossilfuels,On-siteproductionofpowerandsteamingasturbineCHPsystemownedbyanothercompanyCO2fromfossilfuel,CH4,andN2OCO2fromfossilfuel,CH4,andN2OIndirectEmissionsMillSiteSchematicforExampleInventoryResultsBiomassCombustionCO2ClimateNeutralCO2fromBiomassBiomassandcombinationfuel-firedboilersFossilfuel-derivedCO2exportedtoPCCPlantFigure1.SchematicforExampleInventoryResults54Version1.1July8,2005Table16.ExampleGHGInventoryResults–DirectEmissionsemissionsfromsourcesthatarewhollyorpartiallyownedorcontrolledbythecompanyWhereemissionshavebeendeterminedtobeinsignificantornon-material,write“NM”andexplainthebasisforthedeterminationinafootnote.TotalDirectEmissionsmetrictonsCO2CH4N2OCO2Equiv1ProcessandEnergy-RelatedEmissions1StationaryFossilFuelCombustion720000100807469002BiomassCombustionN/A12040149203Make-upChemicals(CaCO3andNa2CO3)5500005500Transportationandmachineryemissions4On-roadvehicles>>>>>>>>>3205Off-roadvehiclesandmachineryNM†NM†NM†NM†Wastemanagementemissions6LandfillemissionsfrommillwastesN/A511107307AnaerobicwastewatertreatmentsystemsN/ANA8OtherDirectEmissionsnotincludedabove–Explain:TotalDirectEmissions(Sumoflines1through8)>>>>>>>>>778370Emissionsassociatedwithexportedelectricityandsteam(asubsetoftotaldirectemissions)9Emissionsrelatedtoelectricityexports062746Carbonintensityofelectricityexports(lbCO2/MWh)<20Carbonintensityofgridreceivingelectricityexports(lbCO2/MWh)1452MethodusedtoestimateGHGintensityofgrid:10Emissionsrelatedtosteamexports000011Totalemissionsattributabletoexports(Sumoflines9and10)062746Explainthemethodusedtodetermineownership/controlofsourcesnotcompletelyownedbythecompany.AprotocolsuchastheWRI/WBCSDGHGProtocolcanbeusedforguidanceondeterminingownership/control.Includeanyotherinformationthatisneededtounderstandtheinventoryresults:†Theseemissionsareuncertainbutwereestimatedusingthehighestfuelconsumptionandemissionfactordataavailableandweredeterminedtobelessthan0.5%ofthemill’semissions.Theyarethereforereportedasnon-material(NM).1CO2-equivalentsarecalculatedmultiplyingindividualgasesbyIPCCGWPvalues,CO2=1,CH4=21,N2O=310,andsummingacrossallthreegases.ItisacceptabletouseemissionfactorsforCO2-equivalentsratherthanestimatingthethreegasesindividually.N/A–NotApplicable-carbondioxideemissionsfrombiomassarenotincludedinGHGtotalsbecausethiscarbonisconsideredpartofthenaturalcycle;i.e.,itisrecycledbetweentheatmosphereandplanttissue.Version1.155July8,2005Table17.ExampleGHGInventoryResults–IndirectEmissionsemissionsattributabletopower/steamimports,andimports/exportsoffossil-CO2MetrictonsWhereemissionshavebeendeterminedtobeinsignificantornon-material,write“NM”andexplainthebasisforthedeterminationinafootnote.CO2CH4N2OCO2Equiv1Indirectemissionsrelatedtoelectricityandsteamimports,includingthosefromoutsourcedpowerislands1IndirectEmissionsrelatedtoelectricityimportsthatareconsumed>>>>>>>>>720002IndirectEmissionsrelatedtosteamimportsthatareconsumed>>>>>>>>>124003Totalindirectemissionsfrompower/steamimports(Sumoflines1through2)84400OtherIndirectEmissions4Descriptionofotherindirectemissionsincludedininventory:0ImportsandExportsoffossilfuel-derivedCO25ImportsofCO2(e.g.,forneutralization)06Exportsoffossilfuel-derivedCO2(e.g.,toPCCPlants)21000Note1:ThisincludesonlythefractionofCO2exportsthatcanbetracedtofossilfuels.Exportsofbiomass-derivedCO2arereportedinAnnexE–SupportingInformationonBiomass.Note2:ThisexportedCO2shouldnotbereportedasanemissioninTable12.Explainthemethodusedtodetermineownership/controlofsourcespartlyownedbythecompany.AprotocolsuchastheWRI/WBCSDGHGProtocolcanbeusedforguidanceondeterminingownership/control.Includeanyotherinformationneededtounderstandtheinventoryresults:1CO2-equivalentsarecalculatedmultiplyingindividualgasesbyIPCCGWPvalues,CO2=1,CH4=21,N2O=310,andsummingacrossallthreegases.ItisacceptabletouseemissionfactorsforCO2-equivalentsratherthanestimatingthethreegasesindividually56Version1.1July8,2005Table18.ExampleGHGInventoryResults–EmissionFactors(EF)UsedtoPreparetheInventoryCO2CH4N2OCO2EquivSourceofEFFossilFuelCombustionFuelCombustionUnitsGasolineforestryequip.66.8tonne/TJHHVTable9Dieselfueltrucksandmachinery78.6tonne/TJHHVTable9Coalboiler88.8tonne/TJHHV0.7kg/TJHHV1.5kg/TJHHVTables2(correctedforunoxidizedC)and5Naturalgasboiler50.2tonne/TJHHV5kg/TJHHV0.1kg/TJHHVTables2(correctedforunoxidizedC)and5BiomassCombustionFuelCombustionUnitsbark&woodresidualfuelsboilerN/A11kg/TJHHV4kg/TJHHVTable8N/AN/AN/AN/AN/AN/AWasteManagementLandfill1emissions:%ofGasCollected=75“k”=0.03“L0”=100m3/Mgdrywt.Landfill2emissions:%ofGasCollected=“k”=“L0”=Landfill3emissions:%ofGasCollected=“k”=“L0”=AnaerobicTreatmentemissions:“EF”=ElectricalPowerandSteamImportsEmissionsfactorsforimportedelectricityPowerpurchasedfromlocalgrid>>>>>>>>>726kgCO2perMWhInformationfrompowersupplierEmissionfactorsforimportedsteamN/A–NotApplicable-carbondioxideemissionsfrombiomassarenotincludedinGHGtotalsbecausethiscarbonisconsideredpartofthenaturalcycle;i.e.,itisrecycledbetweentheatmosphereandplanttissue.Version1.157July8,2005REFERENCESAEATechnology.2001.UKgreenhousegasinventory1990-1999:AnnualreportforsubmissionundertheFrameworkConventiononClimateChange.Oxfordshire,England:NationalEnvironmentalTechnologyCentre.http://www.aeat.co.uk/netcen/airqual/reports/ghg/ghg2.html(29October2004)Apps,M.J.,Kurz,W.A.,Beukema,S.J.,andBhatti,J.S.1999.CarbonbudgetoftheCanadianforestproductsector.25-41inEnvironmentalScienceandPolicyNo.2.ElsevierScienceLtd.Birdsey,R.A.1996.Chapter1–CarbonstorageformajorforesttypesandregionsintheconterminousUnitedStates.Forestsandglobalchange–Vol.2:Forestmanagementopportunitiesformitigatingcarbonemissions.Sampson,N.,andHair,D.(eds.).Washington,DC:AmericanForests.Browning,B.L.(ed.).1975.Thechemistryofwood.NewYork:RobertE.KriegerPublishingCompany.EnvironmentCanada.2004.Canada’sgreenhousegasinventory1990-2002.Ottawa:EnvironmentCanada.http://www.ec.gc.ca/pdb/ghg/inventories_e.cfm(30October2004).EuropeanEnvironmentAgency(EEA).2004.EMEP/CORINAIREmissioninventoryguidebook-Thirdedition,September2004Update.Copenhagen:EuropeanEnvironmentAgency.http://reports.eea.eu.int/EMEPCORINAIR4/en(27October2004).FortumPowerandHeatOy(Fortum).2001.MethaneandnitrousoxideemissionsintheFinnishenergyproduction.Fortum,Finland:FortumPowerandHeatOy,Technology.Georgia-PacificCorporation(GP).2002.ProtocolfortheinventoryofgreenhousegasesinGeorgia-PacificCorporation.Atlanta,GA:Georgia-PacificCorporation.http://www.gp.com/enviro/strategy/protocol.pdf(30October2004).IntergovernmentalPanelonClimateChange(IPCC).1996.Climatechange1995,thescienceofclimatechange.NewYork:CambridgeUniversityPressIntergovernmentalPanelonClimateChange(IPCC).1997a.Revised1996IPCCguidelinesfornationalgreenhousegasinventories:Reportinginstructions(Vol.1).IPCCNationalGreenhouseGasInventoryProgram.http://www.ipcc-nggip.iges.or.jp/public/gl/invs4.htm(30October2004).IntergovernmentalPanelonClimateChange(IPCC).1997b.Revised1996IPCCguidelinesfornationalgreenhousegasinventories:Workbook(Vol.2).IPCCNationalGreenhouseGasInventoryProgram.http://www.ipcc-nggip.iges.or.jp/public/gl/invs5.htm(30October2004).IntergovernmentalPanelonClimateChange(IPCC).1997c.Revised1996IPCCguidelinesfornationalgreenhousegasinventories:Referencemanual(Vol.3).IPCCNational58Version1.1July8,2005GreenhouseGasInventoryProgram.http://www.ipcc-nggip.iges.or.jp/public/gl/invs6.htm(30October2004).IntergovernmentalPanelonClimateChange(IPCC).2000a.Goodpracticeguidanceanduncertaintymanagementinnationalgreenhousegasinventories.IPCCNationalGreenhouseGasInventoryProgram.http://www.ipcc-nggip.iges.or.jp/public/gp/english/(30October2004).IntergovernmentalPanelonClimateChange(IPCC).2000b.IPCCspecialreportonlanduse,land-usechange,andforestry.CambridgeUniversityPress.375pp.http://www.grida.no/climate/ipcc/land_use/(30October2004).IntergovernmentalPanelonClimateChange(IPCC).2001.Thirdassessmentreport(TAR),climatechange2001:Thescientificbasis.WorkingGroup1Report,TechnicalSummary.IPCCNationalGreenhouseGasInventoryProgram.http://www.ipcc.ch/activity/tar.htm(30October2004).IntergovernmentalPanelonClimateChange(IPCC).2003.Goodpracticeguidanceforlanduse,landusechangeandforestry.IPCCNationalGreenhouseGasInventoryProgram.http://www.ipcc-nggip.iges.or.jp/public/gpglulucf/gpglulucf.htm(30October2004).JapanPaperAssociation(JPA).2002.VariouspersonalcommunicationsbetweenJPAandReidMinerofNCASI.Tokyo:JapanPaperAssociation.Kitana,O.,andHall,C.W.(eds.).1989.Biomasshandbook.NewYork:GordonandBreachSciencePublishers.Lewandowski,D.A.2000.Designofthermaloxidationsystemsforvolatileorganiccompounds.p.27.BocaRaton,FL:CRCPress.Loreti,C.P.,F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aterial.Theblackliquor,whichalsocontainsthespentpulpingchemicals,isseparatedfromthewoodfibersbywashing,concentratedbyevaporation,andthensenttoarecoveryfurnacewhereitisburnedundercontrolledconditions.FigureA1.ASimplifiedRepresentationoftheKraftPulpingandChemicalRecoverySystemTherecoveryfurnaceproduceslargeamountsofsteamwhichareusedthroughoutthemill.Inaddition,duetothecontrolledoxygendeficientconditionsinthebottomofthefurnace,amoltensmeltconsistingprimarilyofsodiumcarbonateandsodiumsulfideisproduced.Thesodiumsulfideisformedintherecoveryfurnacebythereductionofavarietyofsulfurcompoundsintheblackliquor.ThesodiumcarbonateisformedbythereactionofsodiumVersion1.1A-3July8,2005compounds(primarilysodiumoxideandsodiumsulfide)withCO2,aproductofcombustionofthewood-derivedmaterialintheblackliquor(i.e.,biomass).Moltensmeltisdischargedfromthebottomoftherecoveryfurnaceanddissolvedinwatertoproducegreenliquor.Subsequently,thesodiumcarbonateinthegreenliquorisconvertedintosodiumhydroxidebyreactingwithcalciumhydroxideincausticizers,producingacalciumcarbonateprecipitate.Whiteliquor,thecombinationofsodiumhydroxideandsodiumsulfideneededforpulping,isproducedbyremovingtheprecipitate.Inthiswaythesodiumloopisclosed.Becausesmallamountsofsodiumarelost,millscommonlymakeupthislossbyaddingsodiumcarbonate,sodiumsulfate,orsodiumhydroxide,dependingonwhetherthemillneedstheadditionalsulfurandthecapacityofvariousprocessesintherecoverysystem.Thecalciumloopintersectsthesodiumloopatthecausticizers.Inthecausticizers,calciumcarbonate(CaCO3)isformedbythereactionofcalciumhydroxidewiththesodiumcarbonateingreenliquor.Thecarboncontainedinthiscalciumcarbonateoriginatedinthewood,wasconvertedtobiomassCO2intherecoveryfurnace,subsequentlyreactedwithsodiumsaltsintherecoveryfurnacetoformsodiumcarbonate,andwasfinallyconvertedtocalciumcarbonateinthecausticizers.Inessence,therefore,thereactionsinthecausticizersaccomplishatransferofbiomasscarbonfromthesodiumlooptothecalciumloop.Thecalciumcarbonateformedinthecausticizersisseparatedfromthewhiteliquor,dewatered(formingamaterialcalledlimemud),andwashedbeforebeingburnedinalimekilnorcalcinertoproducecalciumoxide.TheCO2liberatedintheconversionofcalciumcarbonatetocalciumoxideinthelimekilncontainscarbonwhichoriginatedinwoodandwastransportedtothecalciumloopviathesodiumcarbonateingreenliquor.Therefore,exceptincaseswhereCaCO3isaddedtotherecoverysystemasamake-upchemical,theonlyCO2thatshouldbeincludedinGHGinventoriesisthatamountfromfossilfuelsburnedinthekilnorcalciner.Elsewhereinthisreport,thereisadditionaldiscussionofGHGemissionsthatmaysometimesberelatedtocarbonate-containingmake-upchemicalsusedbysomemills.2.2MethaneSmallamountsofmethanehavebeenfoundinlimekilnemissionsatsomekraftmills.Samplingatthreemillsinthelate1970sfoundthatmethaneconcentrationswereusuallylessthan1ppmbyvolume,althoughvalueshashighas34ppmweremeasured(NCASI1980).Of73measurementsmadeatthethreemills,allbut7werelessthan5ppm.Forthesethreemills,5ppmcorrespondedtoapproximately0.004kgmethanepermetrictonofpulp.Atanassumedlimekilnfuelconsumptionrateof1.5GJ/tonpulp,thisisequalto2.7kgCH4/TJ.IPCCsuggestsemissionfactorsof1.0and1.1kgCH4/TJforoil-firedandgas-firedlimekilns,respectively.(IPCC1997c,Table1-17).Thesefactorswerenotdevelopedforkraftmilllimekilns,however.Althoughthedataarelimitedandold,theNCASIemissionfactorof2.7kgCH4/TJisprobablymoreappropriateforestimatingmethaneemissionsfromkraftmilllimekilnsthanA-4Version1.1July8,2005theIPCCemissionfactorsforcommercialkilns.Theemissionfactorislikelytoberevised,however,asnewdataaregenerated.2.3NitrousOxideBecausenitrousoxideisformedinsomecombustionprocesses,itisappropriatetoexaminethepotentialfornitrousoxideemissionsfromkraftmilllimekilns.Thisgasispotentiallyimportantbecauseitisusuallyassumedtohaveagreenhousegasglobalwarmingpotential310timesgreaterthanCO2.IPCCreviewedtheliteratureandconcludedthatformationofnitrousoxideisunlikelyoutsidearangeofcombustiontemperaturesofapproximately538°Cto927°C(1000oFto1700°F)(IPCC1997c).Thecalcinationoflimecommencesatapproximately816°C(1500oF)and,inalimekiln,normallyinvolvestemperaturesintherangeof980°Cto1200°C(1800oFto2200oF)(Hough1985).Heatingcalciumsolidstothesetemperaturesinalimekilnrequirescombustiontemperaturesabovetherangethoughttobesuitablefornitrousoxideformation.Kraftmilllimekilns,therefore,arenotexpectedtobeasignificantsourceofnitrousoxide.Somemillsusecalcinersinsteadofkilnstoregeneratelime.Becausecalcinersoperateatlowertemperatures(maximumtemperatureofabout870°Cor1600°F)thereappearstobeapotentialforN2Ogeneration,butdataarelacking(Hough1985).Itisreasonable,therefore,toassumethatN2Oemissionsfromlimekilnsaresolowthattheyneednotbereported.Inthecaseofcalciners,however,thisassumptionmaynotbereasonable,buttherearenodatasoitissuggestedthattheN2Oemissionfactorsforcomparable-sizedfossilfuelboilersbeused(seeAnnexA).2.4UseofKraftMillLimeKilnGasestoManufacturePrecipitatedCalciumCarbonateCalciumcarbonatepigmentcanbeusedasacoatingandfillermaterialintheproductionofsomegradesofpaperandpaperboard.Calciumcarbonatepigmentismanufacturedbygrindinglimestoneormarble,orbychemicalprecipitation.Atsomemills,thecorrectcharacterizationoflimekilnemissionsiscomplicatedbythenow-commonpracticeofusingthelimekilnstackgasCO2(orgasfromanotherboiler)tomanufactureprecipitatedcalciumcarbonate(PCC)atsatelliteplants.ThePCCmanufacturingprocessinvolvesthereactionofCO2-richlimekilngaswithpurchasedcalciumoxide(lime)toproducePCC.Althoughothermillstackgasesaresometimesused,thelimekilnstackisfavored,primarilybecauseofitshigherCO2content.WhiletheamountsofCO2usedinPCCmanufacturingatsatelliteplantsappeartobesmallcomparedtotheindustry’soverallemissions,thequantitiescanbesignificantatindividualmillsbecause50%ormoreoftheCO2inthestackgascanbeconsumedinthePCCmanufacturingprocess.Indeed,somekraftmillsusebiomasstosupplyalmostalloftheirenergyneeds,withtheonlysignificantuseoffossilfuelbeingthelimekiln.Atsuchmills,theamountsofCO2capturedinPCCmanufacturecanactuallyexceedtheamountsoffossilCO2emittedbythemill.Version1.1A-5July8,2005BecausetheCO2exportedtoPCCplantsisnotemittedbythemillnorbyanysourceownedbythecompany,thisCO2isreportedasanexportratherthananemission.WhereCO2isexportedfromlimekilns,thegasconsistsofacombinationoffossilfuel-derivedCO2andbiomass-derivedCO2.Inthesuggestedreportingformatforthecalculationtools,thesetwotypesofCO2exportsarereportedseparately.Thedataonexportsoffossilfuel-derivedCO2arereportedwithotherdataonfossilfuel-derivedCO2andtheexportsofbiomass-derivedCO2canbereportedinAnnexE(CO2frombiomasscombustion).WithrespecttoPCCmanufacturedfrommillGHGemissions,itisimportanttonotethatthecalculationtoolsareintendedtohelpcharacterizeafacility’sorcompany’sgreenhousegasemissionsandnotthefateofthoseemissions.NoraretheyintendedtoaddressthelifecycletradeoffsassociatedwithuseofmillemissionsasarawmaterialinPCCmanufacture.Thesearequestionsthatrequireamuchbroaderanalysisthanispossiblewithinthescopeofthisinventoryguidance.Version1.1B-1July8,2005ANNEXBALLOCATINGGREENHOUSEGASEMISSIONSFROMCOMBINEDHEATANDPOWER(CHP)SYSTEMS:RECOMMENDEDGUIDANCEANDREVIEWOFMETHODSThisAnnexcontainsthematerialpresentedontheefficiencymethodinSection12.6ofCalculationToolsforEstimatingGreenhouseGasEmissionsfromPulpandPaperMills,version1.1andadditionalinformationonothermethodsforallocatingCHPemissions.1.0RECOMMENDEDGUIDANCEWhereelectricityisproducedbycombinedheatandpower(CHP)systems,itmaybenecessarytoallocatetheemissionsfromtheCHPsystemtothevariousoutputenergystreams.Ofcourse,ifthemillownstheCHPsystemandusesallofitsoutput,thisisnotnecessarybecausealltheemissionsaredirectemissionsforthemill.Inmanycases,however,amillmayeitherreceiveCHPenergyfromanoutsideproviderorexportaportionofitsownCHPoutput.Forinstance,ifamillisimportingsteamfromanearbypowerplant,itisnecessarytoestimateindirectemissionsassociatedwiththeimportedsteam.Likewise,ifamanufacturerisexportingpowerfromaCHPsystembutusingthesteaminternally,itmaybenecessarytoestimatehowmuchofitsemissionstoattributetotheexportedelectricity.AlthoughthereareseveralmethodsforallocatingemissionsfromCHPsystems,theefficiencymethodisrecommendedinthesecalculationtoolsbecauseitattemptstorelateenergyoutputstotheamountsoffuelusedtogeneratethemand,byextension,totheGHGsproducedingeneratingthem.TheefficiencymethodisoneofthreemethodsrecommendedbyWRI/WBCSD(WRI2004b,c).2.0OVERVIEWOFMETHODSThereareatleastfourmethodsthatcanbeappliedinabroadfashionforallocatingGHGemissionsamongelectricityandsteamorhotwateroutputsfromCHPplants.AllfourmethodspresentedhereininvolveestimatingtotalCHPsystememissionsbasedonfossilfuelcombustionanddistributingthetotalemissionsamongthevariousoutputstreams.Allocationsaremadebasedeitherontheperceivedvalueoftheenergyoutputs,the“usefulenergy”contentofeachenergyoutput,orbyestimatingtheamountoforiginalfuelenergyexpendedincreatingeachenergyoutput.Thefinancialvaluemethodofallocatingemissionsinvolvesassigningamonetaryvaluetoeachenergyoutputstreamandallocatingemissionsaccordingtothevalueoftheenergy.Themethodsfordeterminingthesevaluesaresitespecific,sonoattemptwillbemadetopresentalternativewaystousethisallocationmethod.Therefore,theguidancerecommendsthatcompaniesnotusethefinancialmethodtoallocateemissionsfromCHPsystems.B-2Version1.1July8,2005Theefficiencymethodisbasedonallocatingemissionsaccordingtotheamountoffuelusedtoproduceeachenergyoutput.Themethoduseseitherassumedorestimatedefficienciesforconversionofenergyatvariouspointsintheprocesstobackcalculatetheamountsoffuelassociatedwitheachoutputenergystream.Thismethodcanbeusedinasimplifiedordetailedmanner,andistheapproachrecommendedinthewoodproductsGHGcalculationtools.Theheatcontentandworkpotentialmethodsallocateemissionsbasedontheamountofusefulenergyineachenergyoutput.Bothoftheseallocationmethodsconsidertheenergycontentofelectricalpowertobeof“completeutility,”suchthatalloftheenergyintheelectricityisconsumedinausefulfashionbyaprocess.Theprimarydifferencebetweentheallocationmethodsisinregardtohowtheenergycontentassociatedwithsteamisdetermined.Theheatcontentmethodassumesthattheusefulenergycontentofsteam(orhotwater)isequivalenttotheheatthatcanbeextractedfromit,whereastheworkpotentialmethodassumesthattheusefulenergycontentisequivalenttothemaximumamountofworkthatcanbeextractedfromthesteam.Accordingly,theworkpotentialmethodisnotrecommendedforallocatingemissionsfromCHPsystemswhichincorporateahotwaterenergyoutputstream(workcannotbeextractedfromhotwater).Theefficiency,heatcontent,andworkpotentialmethodswillbedescribedbriefly,followedbyillustrativeexamplesofallocatingGHGemissionsforahypotheticalCHPsystembyeachmethod.2.1EfficiencyMethod–Note:Section2.1.1hereinisidenticaltoSection12.6.1inthereport2.1.1SimplifiedEfficiencyMethodTheefficiencymethodrequiresuseofassumedefficiencyfactorsfortheproductionofpowerandsteam,oractualefficiencyfactorsforeachsteamorpowergenerationdevicebasedondetailedprocessdesignandoperatinginformation.Itisassumedthattheefficiencyofproducinghotwateristhesameastheefficiencyofproducingsteam.Thesimplestapproachtoapplyingtheefficiencymethodistoassignasingleefficiencyfactortoallpoweroutputandasingleefficiencyfactortoallheat(steamandhotwater)output.Thisinformationisusedtocomputeanefficiencyratioequaltotheheatproductionefficiencydividedbythepowerproductionefficiency.Forexample,iftheCHPsystemproducessteamat80%efficiencyandpowerat40%efficiencytheratiois2.Theefficiencyratioisusedratherthantheindividualefficienciesbecause(a)itistheratiothatcontrolstheallocationofemissionsratherthantheindividualefficiencies,and(b)theindividualefficienciesareconstrainedbytheenergybalancesoitisnotpossibletospecifybothindependently.EmissionsfromtheCHPsystemareallocatedbetweentheheatandpoweroutputs,basedonthisratioofefficiencies,usingEquations1and2.Thisapproachisreferredtointhisreportasthesimplifiedefficiencymethod.Thesimplifiedefficiencymethodisrecommendedformillsthatlack,orchoosenottouse,detaileddesignandoperatingdatafromCHPsystems.Version1.1B-3July8,2005PHeffTeffHeeRRPHHEE=⎪⎭⎪⎬⎫⎪⎩⎪⎨⎧×+×=;(Eq.1)where:EH=emissionsshareattributabletoheatproduction,tGHG/yET=totalemissionsfromtheCHPplant,tGHG/yH=heatoutput,GJ/yP=poweroutput,GJ/yReff=ratioofheatproductionefficiencytopowerproductionefficiencyeH=assumedefficiencyoftypicalheatproduction(default=0.8)eP=assumedefficiencyoftypicalelectricpowerproduction(default=0.35)Theemissionshareattributabletoelectricpowerproductionisassignedfromtherelation:HTPEEE−=(Eq.2)where:EP=emissionsshareattributabletoelectricpowerproductionInthesecalculations,theheatinsteamcanbecorrectedtoreflecttheamountofheatinreturnedcondensates.Inusingthesimplifiedefficiencymethod,efficienciesof0.35forpowergenerationand0.8forsteam(orhotwater)generationarerecommended,correspondingtoaratioofefficiencies(Reff)of2.3.Theexamplecalculationbelowmakesuseoftheserecommendeddefaultefficiencyfactors.B-4Version1.1July8,2005ExampleCalculation:AllocatingCHPemissionstothreeoutputstreams–SimplifiedefficiencymethodwithWRI/WBCSDrecommendeddefaultefficiencyfactorsfortheUS.AmillhastheCHPsystemshowninthefollowingfigure,butitislacking(orchoosesnottouse)detailedenergybalanceinformation.Instead,thecompanychoosestousethesimplifiedefficiencymethodandthedefaultefficienciesrecommendedbyWRI/WBCSDfortheUS;0.35forpowergenerationand0.8forsteamgeneration(WRI2004b,c).HRSGFuel2974m3/hrnat.gasStm.TurbineP2=3MWH1=15MW19,500kg/hrsteam170°C,7barSteamHs=19.21MWGas-firedTurbineFuel11538m3/hrnat.gasHeatP1=5MWeffBUsingtheseassumedefficiencies,emissionscanbeallocatedamongthethreeoutputsoftheCHPsystemasfollows(usingabasisofonehourofoperation):Totalsystememissions:Fuel1:CO2(1538m3/hr)x(0.039GJ/m3)x(55.9kgCO2/GJ)=3353kgCO2/hrCH4(1538m3/hr)x(0.039GJ/m3)x(0.0006kgCH4/GJ)x(21CO2-eq./CH4)=0.76kgCO2-eq./hrN2O(1538m3/hr)x(0.039GJ/m3)x(0.0001kgN2O/GJ)x(310CO2-eq./N2O)=1.86kgCO2-eq/hrTotalFuel1emissions=3356kgCO2-eq./hrFuel2:CO2(974m3/hr)x(0.039GJ/m3)x(55.9kgCO2/GJ)=2123kgCO2/hrCH4(974m3/hr)x(0.039GJ/m3)x(0.0014kgCH4/GJ)x(21CO2-eq./CH4)=1.12kgCO2-eq./hrN2O(974m3/hr)x(0.039GJ/m3)x(0.0001kgN2O/GJ)x(310CO2-eq./N2O)=1.18kgCO2-eq./hrTotalFuel2emissions=2126kgCO2-eq./hrTotalCHPsystememissions=3356+2126=5482kgCO2-eq./hrTotalsystempoweroutput=P1+P2=8MW3.235.08.0==effRVersion1.1B-5July8,2005()eqkgCOeqkgCOMW8MW115MWEH22462254823.25=××+=⎭⎬⎫⎩⎨⎧=20,681tCO2eq/yat350d/yoperationeqkgCOeqkgCOeqkgCOEP230202246225482=−==25,368tCO2eq/yrat350d/yoperationUsingthesimplifiedefficiencymethodwithdefaultpowerandsteamefficiencyfactors,therefore,theemissionsfromtheCHPsystemareallocatedtotheoutputstreamsinthefollowingpercentages:•PercentageofCHPemissionstoheatoutput=1002462/5482=44.9%•PercentageofCHPemissionstopoweroutput=1003020/5482=55.1%ThesepercentagescanbeusedtoallocateallGHGemissionsfromtheCHPsystem.Emissionfactorscanbedevelopedfortheenergyoutputs:•EmissionfactorforCHPheatoutput=(2462kgCO2-eq./hr)/15MW=164.1kgCO2-eq./MWh•EmissionfactorforCHPpoweroutput=(3020kgCO2-eq./hr)/8MW=377.5kgCO2-eq./MWh2.1.2DetailedEfficiencyMethodApplicationoftherelationsinEquations1and2toallocateGHGemissionsamongtheenergyoutputsofasimpleCHPsystemwhichincludesonlyasingleheatstream(intheformofsteamorhotwater)andasingleelectricpowerstreammaybefairlystraightforward.However,manyindustrialCHPsystemsincludemultipleheatoutputstreamsandincorporateelectricpowerproductionfrommultiplegeneratorsdrivenbydifferentmotiveforces.TousetheefficiencymethodtoallocateGHGemissionsamongthemultipleenergyoutputsofmorecomplexCHPsystems,Equations1and2canbemodifiedtomoregeneralformssuchas:TE...P2e2PP1e1P...H2e2HH1e1HH1e1HH1E×+++++=⎪⎪⎭⎪⎪⎬⎫⎪⎪⎩⎪⎪⎨⎧⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛(Eq.3)TE...P2e2PP1e1P...H2e2HH1e1HP1e1PP1E×+++++=⎪⎪⎭⎪⎪⎬⎫⎪⎪⎩⎪⎪⎨⎧⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛(Eq.4)Where:EH1=emissionsshareattributabletoheatproductionascontainedinsteamstream1EP1=emissionsshareattributabletoelectricpowerproductionviagenerator1ET=totalemissionsfromtheCHPplantH1=heatoutputcontainedinsteamstream1B-6Version1.1July8,2005H2=heatoutputcontainedinsteamstream2P1=poweroutputfromgenerator1P2=poweroutputfromgenerator2eH1=overallefficiencyofproducingheatcontainedinsteamstream1eH2=overallefficiencyofproducingheatcontainedinsteamstream2eP1=overallefficiencyofproducingelectricpowerviagenerator1eP2=overallefficiencyofproducingelectricpowerviagenerator2Manufacturingfacilitiesmayalreadyhaveenergybalancesthatincorporatethetypeofinformationneededtoperformthedetailedefficiencymethod.Inthesecases,theefficiencymethodisappliedbyusingtheenergybalancestoestimatetheamountoffuelrequiredtoproduceeachCHPoutputstream.ThiscanthenbeconvertedintoGHGallocationsforeachstream.Asinthesimplifiedefficiencymethod,hotwaterstreamsaretreatedinthesamemannerassteamoutputs.Version1.1B-7July8,2005ExampleCalculation:AllocatingemissionsfromacomplexCHPsystem.Figure1depictsahypotheticalCHPsystemthatincludesthreeenergyoutputstreams(onesteamstream,H1,andtwopoweroutputs,P1andP2)andincorporatestwofuelinputs(onetothegas-firedturbineandasecondtotheheatrecoverysteamgenerator(HRSG)).InordertouseEquations3and4toallocateGHGemissionsamongthethreeenergyoutputsofthisCHPsystem,efficiencyfactorsforeachoutputmustbeeitherdevelopedorassumed.HRSGFuel2974m3/hrnat.gas10.55MWStm.TurbineP2=3MWH1=15MW19,500kg/hrsteam170°C,7barSteamHs=19.21MW19,500kg/hrstm540oC,38barGas-firedTurbineFuel11538m3/hrnat.gas16.67MWHeat10.83MWP1=5MWeffBTheCHPsystememissionsarethesameasthosecalculatedinthepreviousexample:TotalFuel1emissions=3356kgCO2-eq./hrTotalFuel2emissions=2126kgCO2-eq./hrTheefficiencyforP1,thepoweroutputfromthegas-firedturbine,hasbeenestimatedat0.3(30%)basedoninformationfromthemanufacturer.Mechanicallossesinthegasturbineareapproximately5%,sothe“efficiency”1ofproducingthe(waste)heatintheturbineexhaustis1-0.05-0.3=0.65,or65%.Theemissionsfromcombustionoffuelinthegas-firedturbinecannowbeallocatedbetweenP1andthewasteheatusingEquations3and4,withonehourofoperationasthebasisforthecalculations:eqkgCOeqkgCO0.6510.83MW0.35MW0.35MWF1EHeateHeatP1e1PP1e1PP1E2167823356=×+=×+=⎪⎪⎭⎪⎪⎬⎫⎪⎪⎩⎪⎪⎨⎧⎟⎠⎞⎜⎝⎛⎟⎠⎞⎜⎝⎛⎟⎠⎞⎜⎝⎛⎪⎪⎭⎪⎪⎬⎫⎪⎪⎩⎪⎪⎨⎧⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛1Theterm“efficiency”isusedheretorepresenttheamountofwasteheatgeneratedinthegasturbinerelativetotheamountoffuelenergyinputtothegasturbine.Althoughwasteheatgenerationratesarenottypicallycharacterizedbyefficiencyfactors,thefactorisrequiredfortheuseoftheefficiencymethodofemissionsallocationinthisexamplebecausethewasteheatfromthegasturbineisanenergyinputtotheHRSG.B-8Version1.1July8,2005eqkgCOeqkgCO0.6510.83MW0.35MW0.6510.83MWF1EHeateHeatP1e1PHeateHeatHeatE2167823356=×+=×+=⎪⎪⎭⎪⎪⎬⎫⎪⎪⎩⎪⎪⎨⎧⎟⎠⎞⎜⎝⎛⎟⎠⎞⎜⎝⎛⎟⎠⎞⎜⎝⎛⎪⎪⎭⎪⎪⎬⎫⎪⎪⎩⎪⎪⎨⎧⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛⎟⎟⎠⎞⎜⎜⎝⎛DevelopmentofefficiencyfactorsforH1andP2iscomplicatedbythefactthattheCHPsystemincorporatestwofuelinputs(F1andF2).SteamenergyproducedintheHRSGisderivedfromacombinationofwasteheatfromthegas-firedturbine(heatthatoriginatedfrompartoftheenergyinfuelstreamF1)andsupplementalfiringofnaturalgas(oftentermedaductburner).InallocatingemissionsassociatedwithoperatingtheHRSG,theexhaustfromthegasturbineistreatedasafuelandtheemissionsallocatedtothisstream(EHeat)areaddedtotheemissionsassociatedwithF2(EF2),andthesetotalemissions(EF2)areallocatedbetweenH1andP2.TherearedifferingefficienciesassociatedwithconvertingeachofthesetwoenergysourcesintosteamintheHRSG.ThemillhasinformationthatindicatesthattheefficiencyoftheHRSGinconvertingtheheatintheturbineexhaustgasintosteamenergyis80%.Theefficiencyassociatedwithcombustionoftheauxiliaryfuelintheductburneris100%(thisistypicallytrueofsupplementallyfiredHRSGs).ThisinformationcanbeusedtodevelopanoverallefficiencyoftheHRSGasfollows:%9083.1055.1083.10%8083.1055.1055.10%100=+×++×=⎟⎠⎞⎜⎝⎛⎟⎠⎞⎜⎝⎛MWMWMWMWMWMWBeffItisassumedthattheefficiencyassociatedwithH1isequivalenttothatofproducingsteamintheHRSG(Hs),90%.Themillhasinformationindicatingthattheefficiencyofthebackpressuresteamturbineinconvertingexpansionintomechanicalwork(isotropicexpansionefficiency)is75%,andthegeneratorwhichconvertsthemechanicalworkintoelectricalpoweris95%efficient.Therefore,theefficiencyofproducingelectricalpoweroutputP2is:(effB)×(effturbine)×(effgenerator)=(0.9)×(0.75)×(0.95)=0.64,or64%.eqkgCOHeatEFEFE23804167821262'2=+=+=eqkgCOeqkgCO0.915MW0.643MW0.643MWP2E283523804=×+=⎪⎪⎭⎪⎪⎬⎫⎪⎪⎩⎪⎪⎨⎧⎟⎠⎞⎜⎝⎛⎟⎠⎞⎜⎝⎛⎟⎠⎞⎜⎝⎛eqkgCOeqkgCO0.915MW0.643MW0.915MWH1E2296923804=×+=⎪⎪⎭⎪⎪⎬⎫⎪⎪⎩⎪⎪⎨⎧⎟⎠⎞⎜⎝⎛⎟⎠⎞⎜⎝⎛⎟⎠⎞⎜⎝⎛Version1.1B-9July8,2005ThefollowingtablepresentsasummaryofemissionsandemissionfactorsforthethreeoutputsinthisCHPexample.TotalEnergyEfficiencySteamTemp.SteamPress.CO2EmissionsCO2EmissionFactor(MW)(°C)(bar)(kgCO2)(kgCO2/MWh)P1(Electricity)50.3N/AN/A1678336P2(Electricity)30.64N/AN/A835278H1(Steam)150.917072969198Total54822.2HeatContentMethodIntheheatcontentmethod,alltheenergyinelectricalpowerisconsidereduseful;however,onlythefractionofthetotalenergyinsteam(orhotwater)thatcanbeusedforprocessheatingisconsidereduseful.Furthermore,itisassumedthatthesteamisusedforindirectheating,withcondensatesreturnedtotheCHPsystem.Alternatively,ifthecondensatesarenotreturnedorifahotwateroutputstreamisconsideredintheallocation,referenceconditionsotherthanthoseshownbelowmaybeused(e.g.,thetemperatureandpressureofboilerfeedwater).Therefore,theusefulenergycontentofsteamcanbecalculatedusingEquation5:)refHi(HiFEnergyUseful−×=(Eq.5)Where:Fi=themassofsteamintonnes(1000kg)Hi=thespecificenthalpyofsteamflowi,inkJ/kgHref=thespecificenthalpyatreferenceconditions(correspondingtoreturnedcondensates,assumeat100°Cand1atmpressure)Ifthequantityofsteam(orhotwater)isgivenintermsoftotalenergy,thecorrespondingmassofsteam(orhotwater)canbecalculatedusingEquation6:iHenergytotaliF=(Eq.6)Asanexample,consideraCHPsystemwhichemitsatotalof174,000tonnesofcarbondioxideperyearwithtotalenergyoutputsasshowninTableB1.Theusefulenergycontentofelectricityisequivalenttothetotalenergy,andforthethreesteamstreamstheusefulenergyiscalculatedfromEquation5.Allocatedcarbondioxideemissionsandanemissionfactor(tonCO2perGJoftotalenergy)foreachenergyoutputarealsoshowninTableB1.B-10Version1.1July8,2005TableB1.AllocationofGHGEmissionsBasedontheHeatContentMethodCombinedHeatandPowersystemtotalCO2emissions=H=174,000tonnesABCDEFTotalEnergySteamTemp.SteamPress.UsefulEnergyCO2EmissionsCO2EmissionFactorEq.1E=H×Di/∑DF=E/A(GJ)(°C)(barg)(GJ)(tonneCO2)(tonneCO2/GJ)Electricity245N/AN/A24514,16757.8Steam1135540040117868,12050.3Steam211003002094754,76249.8Steam37502001063936,95149.3Total34503009174,0002.3WorkPotentialMethodInotherapplications,thesteamgeneratedintheCHPsystemmaybeusedtodrivemechanicalequipment.Inthesecases,theworkpotentialmethodofallocatingemissionsmaybemoreappropriate.TheworkpotentialmethodisnotappropriateforCHPsystemswhichincludeahotwateroutputstream.Asintheheatcontentmethod,theworkpotentialmethodconsidersalltheenergycontainedinelectricalpowertobeusefulandafractionoftheenergyinsteamtobeuseful.However,intheworkpotentialmethodtheusefulenergyfractionofthetotalenergyinsteamcorrespondstothemaximumamountofworkthatcouldbedonebythesteaminanopen(flow),steadystate,thermodynamicallyreversibleprocess.Thethermodynamictermforthisamountofworkisthe“availability”orthe“exergy.”Theexergyofaparticularstream(theusefulenergyparametercorrespondingtotheworkpotentialmethod)relativetoareferencecasecanbecomputedusingEquation7:⎭⎬⎫⎩⎨⎧⎥⎦⎤⎢⎣⎡×+−−⎥⎦⎤⎢⎣⎡×+−×=refS273)ref(TrefHiS273)ref(TiHiFEnergyUseful(Eq.7)where:Fi=themassofsteamintonnes(1000kg)Hi=thespecificenthalpyofsteamflowi,inkJ/kgHref=thespecificenthalpyatreferenceconditions(correspondingtoreturnedcondensates,assumeat100°Cand1atmpressure)Si=thespecificentropyofsteamflowi,inkJ/kg⋅KSref=thespecificentropyatreferenceconditionsTref=thetemperatureatreferenceconditionsTableB2presentstheallocatedcarbondioxideemissionsandemissionfactorsforeachoftheenergyoutputsforthesameexampleCHPsystemcomputedbytheworkpotentialmethod.Version1.1B-11July8,2005TableB2.AllocationofGHGEmissionsBasedontheWorkPotentialMethodCombinedHeatandPowersystemtotalCO2emissions=H=174,000tonnesABCDEFTotalEnergySteamTemp.SteamPress.UsefulEnergyCO2EmissionsCO2EmissionFactorEq.3E=H×Di/∑DF=E/A(GJ)(°C)(barg)(GJ)(tonneCO2)(tonneCO2/GJ)Electricity245N/AN/A24548,200197Steam113554004032063,00046.5Steam211003002021041,20037.5Steam37502001010921,50028.7Total3450884174,000Version1.1C-1July8,2005ANNEXCGREENHOUSEGASESFROMVEHICULARTRAFFICANDMACHINERY:OVERVIEWOFMETHODSINEXISTINGPROTOCOLS1.0OVERVIEWNationalinventoriesofGHGemissionsfrommobilesourcesfocusonhighwaytravelandrail,air,andwatertransport.Highwaytravelisbyfarthemostsignificantcomponentofmobilesourceemissions.Someofthemobileemissionsofinteresttopulpandpapermills,forexampleemissionsfromvehiclesusedatindustrialfacilitiesorinforestryoperations,getlittleornoattention.Someoftheinventorydocumentssuggestemissionfactorsfornon-highwayutilityandconstructionvehiclesthatappeartobeapplicabletosomeofthesesources.TheWRI/WBCSDGHGProtocoldistinguishesbetweendirectandindirectemissionsfrommobilesourcesbasedontheownershiporcontrolofthevehicles.TheWRI/WBCSDProtocolScope1reportingrequirementsincludealldirectemissions,regardlessofwheretheyoccur(WRI2004a).Becausecorporateinventoriesoftenincludebothon-siteandoff-sitevehicularemissions,referencesaregiveninthisannexthatcanbeusedtoestimateemissionsfromavarietyofoff-roadvehiclesandequipmentthataresometimesusedbytheforestproductsindustry.Companiesinterestedinestimatingtheemissionsfromcompany-ownedon-roadvehiclescanuseinformationfromavarietyoforganizations,includingIPCC(1997c)andWRI/WBCSD(WRI2004d).TheWRI/WBCSDcalculationtoolsfortransportationemissionsareavailableontheinternet(WRI2004d)andarebrieflysummarizedhereaswell.TheExcel®workbookthataccompaniesthisreportincorporatessomeofthetransportationcalculationtoolsfromWRI/WBCSD(distance-basedcalculationtoolsfromWRI/WBCSDarenotincludedintheExcelworkbookthataccompaniesthisreport).1.1CarbonDioxideEssentiallyallprotocolssuggestthatCO2emissionsfromtransportationvehiclesandequipmentbecalculatedfromfuelconsumptionandcarboncontentdata.ThisisaffirmedintheRevised1996IPCCGuidelines(IPCC1997c),theMay2000IPCCGoodPracticesdocument(IPCC2000),theEMEP/CORINAIREmissionInventoryGuidebook,thirdedition(EEA2004),andtheWRI/WBCSDGHGProtocolcalculationtools(WRI2004d).Anumberoftheprotocolsalsogivedistance-basedemissionfactors(kgCO2/vehiclekm)asamethodforcrosscheckingtheestimates.Itisreasonabletoexpectthatcompanieswillbeabletoestimatetheconsumptionandcarboncontentoffuelsusedinon-sitevehicles.Lackingsite-specificinformationonthecarboncontentoffuel,companiescanusethevaluespublishedbynationalauthorities.Insomecases,authoritiesissueasingleemissionfactorshowninCO2-equivalentsthatincorporatesemissionsofCH4andN2O.IntheAustralianGreenhouseChallenge(AGO2004),forinstance,theemissionfactorsnotonlyincludeallthreeGHGs,theyalsoincludeC-2Version1.1July8,2005theimpactofupstreamemissionsfromfuelextraction,processing,andtransportation(i.e.,fullfuelcycleemissions).1.2MethaneandNitrousOxide1.2.1IPCC’sRevised1996GuidelinesandMay2000BestPracticesDocumentTheReferenceManualofIPCC’sRevised1996Guidelinescontainsemissionfactorsfor“surfacenon-roadsources.”(IPCC1997c,page1.88)TheRevised1996GuidelinesincludeemissionfactorspublishedbyEMEP/CORINAIREmissionsInventoryHandbook,mostrecentlyupdatedin1996,andbyUSEPA.BothsetsofemissionfactorsareshowninTablesC1andC2.TableC1.FuelConsumption-BasedN2OandCH4EmissionFactorsforNon-RoadMobileSourcesandMachinery(IPCC1997c)(IPCCRevised1996GuidelinestakenfromEMEP/CORINAIR)SourceandEngineTypegN2O/kgfuelgN2O/MJgCH4/kgfuelgCH4/MJForestry–diesel1.30.030.170.004Industry–diesel1.30.030.170.004Railways–diesel1.20.030.180.004Industry–gasoline4stroke0.080.0022.20.05Forestry–gasoline2stroke0.020.00040.047.7Industry–gasoline2stroke0.020.00040.056.0Version1.1C-3July8,2005TableC2.N2OandCH4EmissionFactorsforNon-HighwayVehicles(IPCC1997c)(IPCCRevised1996GuidelinestakenfromUSEPA)SourceandEngineTypegN2O/kgfuelgN2O/MJgCH4/kgfuelgCH4/MJShipsandboatsResidual0.080.0020.230.005Distillate0.080.0020.230.005Gasoline0.080.0020.230.005LocomotivesResidual0.080.0020.250.006Diesel0.080.0020.250.006Coal0.080.0020.250.006FarmequipmentGas/tractor0.080.0020.450.011Othergas0.080.0020.450.011Diesel/tractor0.080.0020.450.011Otherdiesel0.080.0020.450.011ConstructionGasconstruction0.080.0020.180.004Dieselconstruction0.080.0020.180.004Othernon-highwayGassnowmobile0.080.0020.180.004Gassmallutility0.080.0020.180.004Gasheavydutyutility0.080.0020.180.004Dieselheavydutyutility0.080.0020.180.0041.2.2EMEP/CORINAIREmissionInventoryGuidebookTheEMEP/CORINAIREmissionInventoryGuidebookcontainsasecondsetofemissionfactorsthatarebasedonthepoweroutputoftheengine(EEA2004).Theseemissionfactorsarepresentedinawaythatallowsthemtobeadjustedbasedonenginedesignandtheageoftheengine.Theycanbeusedtoestimateemissionsfromallfossilfuelfiredengines.TheemissionfactorsandtheneededadjustmentfactorsareshowninTableC3.C-4Version1.1July8,2005TableC3.CORINAIREngineOutput-BasedN2OandCH4EmissionFactorsforNon-RoadMobileSourcesandMachinery(drawnfromEEA2004)SourceandEngineType/SizeN2O(g/kWh)CH4(g/kWh)BaselinefactorsDieselengines0.350.052-strokegasoline0-2kW0.016.602-strokegasoline2-5kW0.013.552-strokegasoline5-10kW0.012.702-strokegasoline10-18kW0.012.262-strokegasoline18-37kW0.012.012-strokegasoline37-75kW0.011.842-strokegasoline75-130kW0.011.762-strokegasoline130-300kW0.011.694-strokegasoline0-2kW0.035.304-strokegasoline2-5kW0.032.254-strokegasoline5-10kW0.031.404-strokegasoline10-18kW0.030.964-strokegasoline18-37kW0.030.714-strokegasoline37-75kW0.030.544-strokegasoline75-130kW0.030.464-strokegasoline130-300kW0.030.394-strokeLPG0.051.0Pollutantweightingfactorsfordieselengines(multiplybaselinefactorsshownabovebythesevalues)Naturallyaspirateddirectinjection1.00.8Turbo-chargeddirectinjection1.00.8Intercooledturbo-chargeddirectinjection1.00.8Intercooledturbo-chargedprechamberinjection1.00.9Naturallyaspiratedprechamberinjection1.01.0Turbo-chargedprechamberinjection1.00.95Degradationfactors(increaseemissionfactorscalculatedabovebythesevalues)Dieselengines0%peryear1.5%peryear2-strokegasolineengines0%peryear1.4%peryear4-strokegasolineandLPGengines0%peryear1.4%peryear1.2.3AustraliaGreenhouseChallenge–FactorandMethodsWorkbookManufacturersparticipatingintheAustralianGreenhouseChallengeestimateemissionsusingemissionfactorsthatincludeCO2,CH4,andN2O,andalsoaddressfullfuelcycleemissions(i.e.,theyincludeupstreamemissionsfromfuelextraction,processing,andtransport)(AGO2004).Version1.1C-5July8,20051.2.4Finland–GreenhouseGasEmissionsinFinland1990–2002,NationalInventoryReportTheFinnishinventorydocument,GreenhouseGasEmissionsinFinland1990–2002,NationalInventoryReport,containsalistofemissionfactorsfor“smallscalecombustion,”mostofwhicharefromtheCORINAIREmissionInventoryHandbook.SeveralofthefactorsofinteresttotheforestproductsindustryarelistedinTableC4(FinlandMinistryoftheEnvironment2004).TableC4.FinnishEmissionFactorsforOff-roadForestryandIndustrialMachinery(FinlandMinistryoftheEnvironment2004)SourceFuelCH4(mg/MJ)N2O(mg/MJ)Off-roadmachinery/ForestryGasoil(diesel)4.332.5Off-roadmachinery/ForestryGasoline139.00.3Off-roadmachinery/ConstructionGasoil(diesel)4.331.7Off-roadmachinery/ConstructionGasoline133.41.7Off-roadmachinery/OtherGasoil(diesel)4.131.5Off-roadmachinery/OtherGasoline95.01.2Off-roadmachinery/OtherLPG64.63.21.2.5Canada–CanadianGHGChallengeRegistry,GuidetoEntity&Facility-BasedReporting,Canada’sClimateChangeVoluntaryChallengeandRegistry(VCR)–Version3.0,July2004TheVCRguidanceprovidesasetofemissionfactorsforCO2,CH4,andN2Oforuseinestimatingemissionsrelatedtoconsumptionoftransportationfuels(VCR2004).VCRalsoprovidesasetofemissionfactors(intermsofCO2equivalents)whichcanbeusedtoestimateindirectemissionsfortransportation(e.g.,railtransportation,bustravel).VCR-recommendedfactorsarereproducedinTablesC5andC6.C-6Version1.1July8,2005TableC5.CanadianEmissionFactorsforCommonTransportationFuels(reproducedfromTable5ofVCR2004)Vehicle(fuel)CarbonDioxideCO2MethaneCH4NitrousOxideN2OCar(gasoline)2.360kg/l0.00012kg/l0.00026kg/lCar(E10ethanolblendgasoline)2.124kg/l0.00012kg/l0.00026kg/lCar(diesel)2.730kg/l0.00005kg/l0.0002kg/lLighttruck(gasoline)2.360kg/l0.00022kg/l0.00041kg/lLighttruck(E10Ethanolblendgasoline)2.124kg/l0.00022kg/l0.00041kg/lLighttruck(diesel)2.730kg/l0.00007kg/l0.0002kg/lHeavy-dutyvehicle(gasoline)2.360kg/l0.00017kg/l0.001kg/lHeavy-dutyvehicle(E10Ethanolblendgasoline)2.124kg/l0.00017kg/l0.001kg/lHeavy-dutytruck(diesel)2.730kg/l0.00012kg/l0.00008kg/lMotorcycle(gasoline)2.360kg/l0.0014kg/l0.000046kg/lMotorcycle(E10Ethanolblendgasoline)2.124kg/l0.0014kg/l0.000046kg/lPropanevehicles1.500kg/l0.00052kg/l0.000028kg/lNaturalgasvehicles2.758kg/kg0.03210kg/kg0.00009kg/kgOff-roadvehicles(gasoline)2.360kg/l0.0027kg/l0.00005kg/lOff-roadvehicles(E10ethanolblendgasoline)2.124kg/l0.0027kg/l0.00005kg/lOff-roadvehicles(diesel)2.730kg/l0.00014kg/l0.0011kg/lRailroadlocomotives(diesel)2.730kg/l0.00015kg/l0.0011kg/lBoats(gasoline)2.360kg/l0.0013kg/l0.00006kg/lShips(diesel)2.730kg/l0.00015kg/l0.00100kg/lShips(light“distillate”oil)2.830kg/l0.0003kg/l0.00007kg/lShips(heavy“residual”oil)3.090kg/l0.0003kg/l0.00008kg/lConventionalaircraft(aviationgasoline)2.330kg/l0.00219kg/l0.00023kg/lJetaircraft(aviationturbofuel)2.550kg/l0.00008kg/l0.00025kg/lTableC6.CanadianIndirectEmissionFactorsforTransportation(reproducedfromTable6ofVCR2004)Railtransportation(freight)0.0162kgCO2-equiv/tonne-kmRailtransportation(passengers)0.1033kgCO2-equiv/passenger-kmBustravel(urban)0.1460kgCO2-equiv/passenger-kmBustravel(inter-city)0.0565kgCO2-equiv/passenger-kmAirtravel0.1359kgCO2-equiv/passenger-km1.2.6WRI/WBCSDGreenhouseGasProtocolandSupportingDocumentsNotingthatCH4andN2Oemissions“comprisearelativelysmallproportionofoveralltransportationemissions,”theWRI/WBCSDProtocolincludesonlyCO2emissionsfromVersion1.1C-7July8,2005mobilesources.CompaniesaregiventheoptionofestimatingCH4andN2Oemissionsfrommobilesources(WRI2004d).TablesC7andC8containtheWRI/WBCSDGHGProtocoldefaultemissionfactorsaccordingtofueluseanddistancetraveled.TableC7.DefaultEmissionFactorsforDifferentTransportationFuels(WRI2004d)FueltypeBasedonLowerHeatValuekgCO2/GJGasoline/petrol69.25Kerosene71.45Jetfuel70.72(EIA)Aviationgasoline69.11(EIA)Diesel74.01Distillatefueloilno.174.01Distillatefueloilno.274.01Residualfueloilno.474.01Residualfueloilno.577.30Residualfueloilno.677.30LPG63.20Lubricants73.28Anthracite98.30Bituminouscoal94.53Propane62.99(EIA)Sub-bituminouscoal96.00Wood,woodresidualfuels100.44(EIA)Naturalgas56.06C-8Version1.1July8,2005TableC8.DefaultFuelEconomyFactorsforDifferentTypesofMobileSourcesandActivityData(WRI2004d)VehicleTypeLiters/100kmmpggramCO2/kmNewsmallgas/electrichybrid4.256100.1Smallgasauto,hwy7.332175.1Smallgasauto,city9.026215.5Mediumgasauto,hwy7.830186.8Mediumgasauto,city10.722254.7Largegasauto,hwy9.425224.1Largegasauto,city13.118311.3Mediumstationwagon,hwy8.727207.5Mediumstationwagon,city11.820280.1Minivan,hwy9.824233.5Minivan,city13.118311.3Largevan,hwy13.118311.3Largevan,city16.814400.2Midsizepick-uptruck,hwy10.722254.7Pick-uptruck,city13.817329.6Largepick-uptruck,hwy13.118311.3Largepick-uptruck,city15.715373.5LPGauto11.221266Dieselauto9.824233Gasolinelighttruck16.814400Gasolineheavytruck39.26924Diesellighttruck15.715374Dieselheavytruck33.67870Lightmotorcycle3.96093Dieselbus35.16.71035Version1.1D-1July8,2005ANNEXDGREENHOUSEGASESFROMWASTEMANAGEMENTATPULPANDPAPERMILLS:RECOMMENDEDAPPROACHANDREVIEWOFEXISTINGMETHODS1.0RECOMMENDEDAPPROACHFORESTIMATINGCH4EMISSIONSFROMLANDFILLS[Note:MuchofSection1.0isidenticaltoSection14intheCalculationToolsReport]Thesecalculationtoolshavebeendevelopedassumingthatmanycompanieswillincludecompany-ownedlandfillswithininventoryboundaries.Thesetoolscanalsobeusedincaseswhereamanufacturingfacility’sprocesswasteisbeingdisposedinamunicipalsolidwastelandfillandthecompanyisinterestedinestimatingthefacility’scontributiontothemunicipallandfillemissions.Thereportingformat,however,hasbeenpreparedassumingthatonlyemissionsfromcompany-ownedlandfillswillbereported.Asisthecasewithmostwidelyacceptedprotocols,onlyCH4emissionsareaddressedinthesetoolsbecausetheCO2fromlandfillsiscomposedofbiomasscarbon(notcountedasagreenhousegas)andtheN2Oemissionsareassumedtobenegligible.AnemissionfactorforlandfilledwasteispresentedinTable1ofthemainbodyofthisreport.Thisfactorisbasedonanumberofconservativeassumptionsand,inmostcases,isexpectedtobehigherthantheactualemissionsattributabletolandfilledpulpandpapermillwaste.Theemissionfactorcanbeuseful,however,indecidingwhetherlandfillemissionsarematerialtotheresultsoftheinventory.Forpreparinganestimatetouseintheinventoryresults,however,thesecalculationtoolsrecommendthemethodsdescribedherein,allofwhicharecontainedintheExcel®workbookthataccompaniesthisreport.1.1UsingDatafromLandfillGasCollectionSystemsInsomecases,companylandfillsarecappedwithlowpermeabilitycovermaterialandthelandfillgasiscollected.Inmanyofthesesituations,theamountsofmethanecollectedanddestroyedcanbeestimatedfromsite-specificdata.IPCCrecommendsthatthisinformationbeusedbysubtractingtheamountsofmethanedestroyedfromtheamountsofmethanethatthecompanyestimatesaregeneratedbythelandfill.Theproblemwiththisapproachisthat,becauseofthelargeuncertaintiesinestimatingmethanegeneration,theamountsburned(whicharemeasured)couldeasilybegreaterthantheamountsgenerated(whichareestimated),resultinginanegativerelease.Itisequallypossiblethatthecomparisonofestimatedgenerationratestomeasuredcollectionratescouldsuggestimpossiblylowcollectionefficiencies,dueonlytotheuncertaintiesinestimatingmethanegeneration.Analternativeapproachisavailabletocompaniesthatmeasuretheamountsofmethanecapturedinthecollectionsystem.Thealternativeapproachistoestimatethecollectionefficiencyofthecollectionsystemandback-calculatetheamountsofmethanegenerated.Forinstance,ifamanufacturingplantwithacappedlandfillhasdeterminedthatitscollectionD-2Version1.1July8,2005systemcollects90tonsofmethaneperyearandestimatesthatthecollectionefficiencyis90%,itmeansthat100tonsofmethaneweregenerated.Theproblemwiththisapproachisthattheeffectivenessoflandfillgascollectionsystemsisvariableanduncertain.Reportedcollectionefficienciesrangefrom60to85%(USEPA1998d).ThisvariabilityanduncertaintyhascausedIPCCtotakethepositionthat“theuseofundocumentedestimatesoflandfillgasrecoverypotentialisnotappropriate,assuchestimatestendtooverestimatetheamountofrecovery”(IPCC2000).Nonetheless,thisapproachisbuiltaroundameasuredvalue–theamountofgascollected.Thus,itisreasonabletoexpectthatinsomecasesitmayyieldmoreaccurateestimatesthanIPCC’sdefaultmethodology.ThisisespeciallytrueforforestproductsindustrylandfillsbecauseofthelimiteddataforderivingtheparametervaluesneededtouseIPCC’sdefaultmethodologyonforestproductsindustrywastes.Therefore,thesecalculationtoolsrecommendthatwherelandfillsarecoveredwithlowpermeabilitycapsandequippedwithlandfillgascollectionsystemsconstructedandoperatedtonormalstandards,themethanegenerationratesshouldbebackcalculatedfrommeasurementsoftheamountsofmethanecollectedandestimatesofcollectionefficiency.Adefaultcollectionefficiencyof75%hasbeenusedbysomeauthoritiesandisrecommendedhere,unlesssite-specificcollectionefficiencydataareavailable(USEPA1998d).ThesecalculationtoolsalsoassumethatallofthemethanethatiscapturedandburnedisconvertedtobiomassCO2andthereforedoesnothavetobeincludedintheinventory.Usingthesedefaultvaluesandassumptions,estimatesofmethanegenerationcanbedevelopedusingEquation1.CH4(m3/y)releasedtotheatmosphere=[(REC/FRCOLL)(1–FRCOLL)FRMETH(1–OX)]+[RECFRMETH(1–FRBURN)](Eq.1)where:REC=amountoflandfillgascollected,determinedonasite-specificbasis,m3/yFRCOLL=fractionofgeneratedlandfillgasthatiscollected,defaultis0.75FRMETH=fractionofmethaneinlandfillgas,defaultis0.5OX=fractionofmethaneoxidizedinthesurfacelayerofthelandfill,defaultis0.1FRBURN=fractionofcollectedmethanethatisburned,site-specificdetermination1.2EstimatingLandfillMethaneEmissionsatLandfillswithoutGasCollectionData1.2.1TheSimplifiedFirstOrderDecayApproachWheretheapproachdescribedinSection1.1cannotbeused,itisrecommendedthatcompaniesemploythefirstorderdecaymodelapproachforestimatinglandfillgasemissionsusingparametervaluesderivedforpulpandpaperindustrylandfills.ThisapproachisthedefaultmethodrecommendedbyIPCCandisusedbyanumberofnationalauthorities(IPCC2000).ItcanbeusedtoestimateCH4emissionsfromactiveandinactivelandfills.Incaseswheretheannualdepositsare(orareassumedtobe)constantIPCC’sdefaultmethodreducestotwoequations.ThisapproachshouldbeadequateunlesstheamountsortypesofVersion1.1D-3July8,2005wastebeinglandfilledhavechangedsignificantlyfromyeartoyear,orthelandfilldesignoroperationhavebeenchangedinawaythatwouldsignificantlyimpactmethanegenerationorrelease(e.g.,agascollectionsystemisinstalled).CH4(m3/y)generatedfromallwasteinthelandfill=RL0(e-kC-e-kT)(Eq.2)where:R=averageamountofwastesenttolandfillperyear,Mg/yL0=ultimatemethanegenerationpotential,m3/Mgwastek=methanegenerationrateconstant,1/yC=timesincelandfillstoppedreceivingwaste,yT=yearssincelandfillopened,y(Note:RandL0canbeinunitsofwetweight,dryweight,degradableorganiccarbon,orotherunitsbuttheunitsforRandL0mustbethesame.)Notallmethanethatisgeneratedissubsequentlyreleasedtotheatmosphere.Toestimateatmosphericreleases,usetheresultfromEquation2inEquation3.Forlandfillswithmoderngascollectionandcombustionsystemsbutnomeasurementsofquantitiesofgascollected,theamountofmethanerecoveredcanbeassumedtobe75%ofthatgenerated(USEPA1998d).CH4(m3/y)released=[(CH4generated–CH4recovered)(1–OX)]+[CH4recovered(1-FRBURN)](Eq.3)where:CH4generated=fromEquation2CH4recovered=amountofmethanecollected,site-specificdeterminationOX=fractionoxidizedinthesurfacelayerofthelandfillbeforeescaping,usuallyassumedtobe0.1FRBURN=fractionofcollectedmethanethatisburned,site-specificdeterminationIftheamountsbeinglandfilledhavechangedsignificantlyorifthelandfilldesignhasbeenalteredsothatsomeoftheparametervalueswouldhavechangedsubstantially,amoreinvolvedapproachmaybeneeded.Todealwiththesemorecomplicatedsituations,manyprotocolsrecommendmodelingthegasgeneratedannuallyfromeachyear’sdepositsandthemsummingtheamountsthatarepredictedtooccurinthecurrentyear.ThismoredetailedanalysisisdescribedinSection1.2.2.AnumberofsourcesfortheparametervaluesL0andkneededintheseequationsareshown.Unfortunately,thevaluesvaryconsiderablyfromoneprotocoltothenextandthevaluesarebasedonveryfewdata.1.2.2DetailedFirstOrderDecayApproachToallowyear-to-yearvariationsintheamountsofwastesenttolandfill,IPCCsuggestsavariationofthisapproach.Usingthisvariation,startinyear1andcalculatehowmuchmethanewillbegeneratedineachsubsequentyearbywastedepositedinthatyearusingEquations4and5.D-4Version1.1July8,2005CH4generatedinagivenyearbywastedepositedinanearlieryear(m3/y=kRyL0(e-k[T-Y])(Eq.4)where:k=methanegenerationrateconstant,1/yrRY,=theamountofwastesenttolandfillinyearY,Mg/yrL0,=ultimatemethanegenerationpotential,m3/MgwasteT=yearforwhichemissionsarebeingestimatedgivenintermsofyearssincethelandfillopenedY=yearafterlandfillopenedthatwastewasdisposedThus(T-Y)isequaltothenumberofyearsthewastehasbeeninplacepriortotheyearforwhichemissionsarebeingestimated.CH4(m3/y)released=[(CH4generated–CH4recovered)(1–OX)]+[CH4recovered(1-FRBURN)](Eq.5)where:CH4generated=fromEquation4CH4recovered=amountofmethanecollected,site-specificdeterminationOX=fractionoxidizedinthesurfacelayerofthelandfillbeforeescaping,usuallyassumedtobe0.1FRBURN=fractionofcollectedmethanethatisburned,site-specificdeterminationToperformthecalculations,estimatehowmuchwastewasdepositedeveryyearsincethelandfillwasopened.IPCCindicatesthatforveryoldlandfills,itispossibletolimittheretrospectiveperiodtoonestartingatleastthreewastedegradationhalf-livesbeforethecurrentyear.Giventheslowdegradationobservedinmanyforestproductsindustrywastes,25yearsisprobablytheminimumthatwouldsatisfythiscriterion.Foreachyear’sdeposit,estimateforthatyearandeachfollowingyeartheamountofmethanereleased.Insubsequentyears,theamountofmethanereleasedisthesumoftheamountsestimatedfromeachprioryear’sdepositsthatwereprojectedtooccurinthatyear.Thecalculationsworklikethis:inyear1youdepositamountAandestimatethatinyears1,2,3,…itwillreleaseX1,X2,X3,…tonsofmethane,respectively.ThereportedemissionsforyearoneareX1tonsofmethane.Inyear2youdepositamountBandestimatethatinyears2,3,4,…itwillreleaseY2,Y3,Y4,…tonsofmethane,respectively.Theemissionsreportedforyear2areX2plusY2tonsmethane.Inyear3,youdepositamountCandestimatethatinyears3,4,5,…itwillreleaseZ3,Z4,Z5,…tonsofmethane,respectively.Thereportedemissionsforyear3areX3plusY3plusZ3tonsofmethane.Thisprocessrepeatsitselfeveryyear.ThevaluesforkandL0arethesameasthoseusedinthesimplifiedfirstorderapproach.1.2.3FirstOrderMethaneGenerationRateConstant,kEvenformunicipalwastelandfills,thereislargeuncertaintyabouttheproperfirstorderrateconstant.Thecorrectvalueforforestproductsindustrylandfillsisevenmoreuncertain.Theguidanceofferedbythesourcesreviewedinthisstudyissummarizedhere.Version1.1D-5July8,2005•IPCC–kvariesfrom0.005to0.4peryear,withadefaultof0.05/yrforMSW(IPCC1997c)•UK–kvariesfrom0.05/yrforslowlydegradingwasteto0.185/yrforrapidlydegradingwaste(AEATechnology2001)•Sweden–kequals0.09/yrforalllandfills(SwedishEPA2004)•Canada–kforwoodwastelandfillsequals0.01/yr,andvariesbyprovinceforMSWlandfills(EnvironmentCanada2004)•USEPA–kequals0.04/yrforareasreceivingatleast25inches(63.5cm)ofprecipitationand0.02/yrfordrierareas(forMSWlandfills)(USEPA1998d)•Finland–Initsmostrecentnationalinventory,FinlandusedtheTier2methodofIPCC(FinlandMinistryoftheEnvironment2004).Inthe1990–2002inventory,FinlandMinistryoftheEnvironmentprovideskvaluesfordifferentwastes:k1=0.2(foodwasteinMSWandsludges)k2=0.03(woodwasteinMSWandinconstructionanddemolitionwaste,paperwastecontaininglignininMSW)k3=0.05(industrialsolidwasteandotherfractionsofMSWthanabove)1.2.4UltimateMethaneGenerationPotential,L0Again,thereisagreatdealofvariabilityinthevaluesbeingusedforL0.TheparametervaluesshownareforMSWunlessotherwiseindicated.ItisalsoimportanttonotethatL0canbeexpressedaswetweight,dryweight,oranumberofotherways.Anyformisacceptable,buttheunitsofL0andR(theamountofwastedisposed)mustbethesame.Valuesgivenformunicipalsolidwasteareoftenforwetwasteasdisposed.•IPCC–ThesourcescitedbyIPCCindicatethatL0canvaryfromlessthan100toover200m3/Mg.Anequationisprovidedforcalculatingasite-specificL0(IPCC1997c):L0=(DOC,fractiondegradableorganiccarboninwaste)x(DOCf,fractionofDOCthatdegradesintolandfillgas)x(16/12,toconvertcarbontomethane)x(F,fractionCH4ingasfromamanagedlandfill,defaultvalueis0.5)x(MCF,amountofmethaneinlandfillgasrelativetoamanagedlandfill)ForMSWlandfilldefaultvalues,IPCCrecommends(IPCC1997c,2000):DOC–thedefaultvaluesfordifferentcountriesrangefrom0.08to0.21,butsite-specificdeterminationsarerecommendedDOCf–thedefaultrangeiftheDOCincludesligninis0.5to0.6F–defaultis0.5MCF–1.0formodernmanagedlandfills,0.4forshallowunmanagedlandfills(lessthan5mdeep),and0.8fordeeperunmanagedlandfillsD-6Version1.1July8,2005•UK–TheIPCCequationisusedtocalculateL0.TheDOCfordifferenttypesofwasteweredeterminedfromanationalstudy.DOCfwasassumedtobe0.6.Fwasusually0.5,but0.3wasusedforold,shallowsites.MCFwasassumedtobe1.0(AEATechnology2001).•Sweden–SwedenusesanL0of45kgCH4/tonofwastespecificallyforpulpandpapermillsludgelandfills.Thisisequivalentto63m3/Mg(SwedishEPA2004).•Finland–AlthoughFinlanddidnotusethefirstordermodelapproachforlandfillmethaneinearliernationalinventories,theapproachusedstillrequiresestimationofL0.FinlandusedtheIPCCequationforL0andthevaluespresentedhereforthevariablesintheequation(TechnicalResearchCenterofFinland2001):DOC=0.4forpaperandcardboard,wetweightbasis=0.3forwoodandbark,wetweightbasis=0.1fordeinkingwaste,wetwastebasis(definitionisuncertain,asdeinkingsludgeislistedseparately)=0.45forestindustrysludge–unspecified,dryweightbasis(assumed30%solids)=0.3deinkingsludge,dryweightbasis(assumed30%solids)=0.3forestindustryfibersludge,dryweightbasis(assumed30%solids)DOCf=0.5(reflectslowtemperatureandlessthanoptimalconditionsfordecompositioninFinnishlandfills)MCF=0.7(assumeshalfofwastegoestosmalllandfillswithMCF=0.4andtherestgoestolargelandfillswithMCF=1)F=0.5PuttingthesetogetherusingarangeinDOCof0.3to0.45forwoodproductsindustrywastesonadryweightbasisandassuminganMCFof1,thecalculatedrangeforL0is0.1to0.15kgCH4/kgdrywasteor140to210m3/Mg.•Canada–Tocalculatethemethanepotentialforwoodwastelandfills,CanadausesanL0of118kgCH4/tonwoodwaste,whichconvertsto165m3/Mg.ForMSWlandfills,CanadahasusedanL0valueof165kgCH4/tonfortheyears1941throughto1989.Forsubsequentyears,avalueforL0of117kgCH4/tonisrecommendedforMSWlandfills(EnvironmentCanada2004).•UnitedStates–EPA’scompilationofemissionfactors(AP-42)indicatesthatavalueof100m3/MgisrecommendedasthedefaultfactorformostMSWlandfills(USEPA1998d).1.2.5RecommendedDefaultValuesforkandL0Forsituationswherewastewatertreatmentsludgeisamajorconstituentofthewaste,reasonablevaluesfortherateconstant,k,fallintherangeof0.01to0.1/yr,whilethoseforL0fallbetween50and200m3/Mg.NCASIisconductingresearchthatshouldnarrowtheseranges.InitialindicationsarethattheamountsofgasgeneratedinforestproductsindustrylandfillsarelessthanwouldbepredictedusingparametervaluesdevelopedformunicipalVersion1.1D-7July8,2005solidwaste(NCASI1999).Withthisknowledge,itisrecommendedthatuntilthecurrentresearchiscompleted,andunlesscompanieshavecountry-specificorsite-specificfactorsthataremoreappropriatefortheirwastes,companiesusetheparametervaluesshowninTableD1.TableD1.RecommendedDefaultValuesforkandL0forEstimatingWoodProductsIndustryLandfillMethaneEmissionsParameterDefaultValuek0.03y-1L0100m3/Mgdryweightofwaste2.0RECOMMENDEDAPPROACHFORESTIMATINGCH4EMISSIONSFROMTHEANAEROBICTREATMENTOFWASTEWATERORSLUDGE[Note:MostofSection2.0isidenticaltoSection15intheCalculationToolsReport]MostexistingGHGprotocolsaddressGHGemissionsonlyfromanaerobictreatmentanddigestionprocesses.Therefore,thesecalculationtoolshavebeendevelopedassumingthatemissionsfromothertypesofwastewaterandsludgetreatmentprocessesarenegligible.Althoughaerobicandfacultativetreatmentsystemsmayhavezoneswithdepleteddissolvedoxygen,methanegenerationratesinaeratedstabilizationbasins,activatedsludgesystems,andtheirassociatedretentionpondswouldbeexpectedtobemuchlessthaninanaerobicsystems.Inanyevent,duetolackofdata,itisnotpossibletoreasonablyestimateemissionsfromaerobicandfacultativetreatmentoperations.Evenforanaerobicsystems,onlyCH4emissionsneedtobeestimatedbecause(a)theCO2emittedfromwastewaterandsludgetreatmentoperationscontainsbiomasscarbonwhichisnotincludedinmostGHGprotocols;and(b)otherprotocolsassumethatN2Oemissions,ifany,occurafterthewastewaterisdischarged.2.1AnaerobicTreatmentOperationswhereOff-GasesareCapturedInmanycases,anaerobictreatmentsystemsarecoveredandthegasesarecollectedandburned.Oneofthepurposesofthesecollectionsystemsisthepreventionofodors,andtoaccomplishthisobjective,thesystemsmustbehighlyefficient.ForpurposesofaGHGinventoryitisreasonabletoassume,therefore,thatwheremethaneemissionsfromanaerobictreatmentoperationsarecapturedandburned,thecollectionanddestructioniscompleteandnomethaneisemitted.Ifcircumstancesatamillsuggestthatnon-trivialamountsofmethaneareescapingcollection,themillmayneedtoundertakeeffortstoaccountforthesereleases,butsuchcircumstancesareexpectedtobeunusualatmillsthatcollectandburnthesegases.Ofcourse,ifthegasesarecollectedbutreleasedtotheatmosphereratherthanbeingburned,theyshouldbeincludedintheinventory.D-8Version1.1July8,20052.2AnaerobicTreatmentOperationswhereOff-GasesareReleasedtotheAtmosphereWhereoff-gasesfromanaerobictreatmentoperationsarenotcollectedandburned,itisnecessarytoestimatethereleasesofmethanetotheatmosphere.Insomecases,forinstancewherethegasesarereleasedthroughaventinacoveredvessel,thereleasescanbemeasureddirectly.Inmostothercases,theymustbeestimated.ThesecalculationtoolssuggesttheuseoftheIPCCdefaultmethodologyasdescribedintheMay2000GoodPracticesdocumentandshowninEquation6(IPCC2000).AlthoughtheIPCCdocumentallowstheequationtobeappliedtosystemsthatarenotcompletelyanaerobic(bymultiplyingtheresultbyanarbitraryadjustmentfactoroflessthanone),therearenodatacurrentlyavailabletosupporttheselectionoftheadjustmentfactor.Itisrecommended,therefore,thatmethaneemissionsbeestimatedonlyfromanaerobictreatmentorsludgedigestionsystemsuntilsuchtimeasfactorsforothertypesofsystemsareavailable.AnaerobicTreatmentPlantMethaneEmissions(kg/y)=(OCxEF)–B(Eq.6)where:OC=BODorCODofthefeedtotheanaerobicsystem,kg/yearEF=emissionfactor,defaultvalues=0.25kgCH4/kgCODinthefeedor0.6kgCH4/kgBODinthefeed(oranotherBOD-basedfactordevelopedbymultiplyingtheCOD-basedfactorof0.25kgCH4/kgCODbythesite-specificCOD/BODratio)B=methanecapturedandburned,kgCH4/year,determinedonasite-specificbasisIfthesolidsarehandledseparately,emissionsfromsludgedigestionwouldbecalculatedusingEquation7.Incaseswheresludgeisburned,itisincludedinthecalculationsforGHGemissionsfrombiomassburning,discussedelsewhere.AnaerobicSludgeDigestionPlantMethaneEmissions(kg/y)=(OCsxEFs)-B(Eq.7)where:OCs=organiccontentofthesludgeEFs=emissionfactor,inunitsconsistentwithOCs;IPCC’sdefaultvalueis0.25kgCH4/kgCODinthesludgefeedB=methanecapturedandburned,kgCH4/yr,determinedonasite-specificbasisUndermostprotocols,emissionsofN2Ofromwastewaterareassumedtotakeplaceafterwastewaterisdischargedintoreceivingwaters.Theseemissions,therefore,arenotaddressedinthesetools.3.0OVERVIEWOFEXISTINGAPPROACHES3.1IPCC–Revised1996IPCCGuidelinesforNationalGreenhouseGasInventoriesandGoodPracticeGuidanceandUncertaintyManagementinNationalGreenhouseGasInventoriesNote:Inthefollowingdiscussion,someofthesymbolsusedaredifferentthanthoseusedintheIPCCdocuments.ThishasbeendoneinanattempttoeliminatepotentialconfusionamongvariableshavingsimilarsymbolsintheIPCCdocuments.Version1.1D-9July8,20053.1.1Landfills–TheAll-in-One-YearApproachTheIPCCdefaultmethodologyforestimatingmethaneemissionsfromlandfillsislimitedtomunicipalsolidwastelandfills.Chapter6ofthe1996IPCCGuidelinesReferenceManual(IPCC1997c)andChapter5oftheMay2000GoodPracticesdocument(IPCC2000)outlinetwogeneralapproachesforestimatinglandfillemissions.Thefirstassumesthatallorganicmatterdegradesintheyearitisplacedinthelandfill,whilethesecondusesafirstordermodeltoestimatetheamountsreleasedovertime.TheGoodPracticesdocumentindicatesthatthefirstorderdecayapproachshouldbeusedwherepossible(IPCC2000).Theall-in-one-yearapproachstartswithanestimateofthedegradableorganiccarbon(DOC)contentofthewastegoingtolandfill.IPCCprovidesthedefaultvaluesforcertainlargevolumematerialsshowninTableD2.TableD2.DefaultDOCValuesforMajorWasteStreamsfromIPCC’s1996RevisedMethodology(valuesarefor“wetorfresh”materialsinmunicipalsolidwaste)WasteStreamDegradableOrganicCarbon,%byweightPaperandtextiles40Gardenandparkwastesandothernon-foodorganicputrescibles17Foodwaste15Woodandstrawwaste(excludinglignin)30Oftheamountofcarbonthatisdegradableorganiccarbon,onlyafractionisconvertedintolandfillgas.ThisfractionisgiventhesymbolDOCf.IPCC’s1996Guidancereliesonasimplemodeltogenerateadefaultvalueof0.77forDOCf,butIPCC’sMay2000GoodPracticeGuidanceandUncertaintyManagementdocumentindicatesthatthisappearstobetoohighunlesslignincarbonisexcludedfromtheDOCvalue.TheMay2000documentgoesontosaythata“goodpractice”defaultvalueof0.5to0.6shouldbeusedforDOCfincaseswhereligninisincludedintheDOCunlessbettersite-specificdataareavailable(IPCC2000).IPCCthenappliesamethanecorrectionfactor(MCF),whichisintendedtoaccountforthefactthatlandfilldesignandoperationcaninfluencethetendencyofdegradablecarbontodecomposeintocarbondioxideratherthanmethane.TheMCFissimplyameasureoftherelativemethanegenerationpotentialofunmanagedlandfillscomparedtomanagedlandfills.Alandfillis“managed”ifitinvolvescontrolledplacementofwaste,adegreeofcontroloveraccess,andatleastoneofthefollowing:covermaterial,mechanicalcompacting,orlevelingofwaste.Managedlandfillsareusedasthebaselinecondition,sotheMCFis1.0forsuchlandfills.TheMCFforshallow,unmanagedlandfills(lessthan5mdeep)is0.4,whilethefactorfordeeper,unmanagedlandfillsis0.8.Atamanagedlandfill,thedefaultassumptionisthatmethanecomprises50%ofthelandfillgas.TheMCFsmodifythisassumptionforunmanagedlandfills;i.e.,methanecomprises40%ofthegasfromdeep,unmanagedlandfills(0.8x50%)and20%ofthegasfromshallow,unmanagedlandfills(0.4x50%).D-10Version1.1July8,2005Gasistrappedandburnedatmanylandfills,convertingthecarbontobiomass-CO2.Methanegeneratedwithinalandfillmayalsobeconvertedtobiomass-CO2asitmigratesthroughthesurfaceofthelandfill.BecausetheCO2formedfromlandfillmethaneisbiomasscarbon,itisnotincludedinIPCCemissioninventories.InIPCC’swords,“[d]ecompositionoforganicmaterialderivedfrombiomasssources(e.g.,crops,forests)whichareregrownonanannualbasisistheprimarysourceofCO2releasedfromwaste.Hence,theseCO2emissionsarenottreatedasnetemissionsfromwasteintheIPCCMethodology.Ifbiomassrawmaterialsarenotbeingsustainablyproduced,thenetCO2releaseshouldbecalculatedandreportedundertheAgricultureandLand-UseChangeandForestryChapters”(IPCC1997c).Overall,therefore,theIPCCall-in-one-yearapproachinvolvesthesecalculations:Methanegenerated=(amountofwastesenttolandfill)xDOCxDOCfx16/12x0.5xMCF(Eq.8)where:DOC=fractiondegradableorganiccarboninwaste(basedonthesameunitsasusedtomeasuretheamountofwastesenttolandfill)DOCf=fractionofDOCthatdegradesintolandfillgas16/12=conversionfactorfromcarbontomethane0.5=fractionmethaneingasfromamanagedlandfill,defaultvalueMCF=amountofmethaneinlandfillgasrelativetoamanagedlandfill(managedlandfillMCF=1)Methanereleased=(Methanegenerated–REC)x(1–OX)(Eq.9)where:REC=amountofmethaneconvertedtoCO2byburningOX=fractionofmethaneconvertedtoCO2byoxidationinthelandfillcover(defaultvalueiszerobutIPCC’sMay2000GoodPracticesdocumentindicatesthatavalueof0.1canbeusedforwellmanagedlandfillsinindustrializedcountries)3.1.2Landfills–TheFirstOrderDecayApproachIPCCsuggeststwoapproachesformodelingmethanereleasesfromlandfillsovertime.Thefirstusestheaveragewasteacceptancerateoverthelifeofthelandfill(seeSection1.2.1ofthisannexforadescription),whilethesecondconsiderseachyear’swasteseparately(seeSection1.2.2ofthisannexforadescription)(IPCC1997c).3.1.3WastewaterTreatmentandAnaerobicSludgeDigestionInaerobictreatmentplants,mostoftheorganicmatterinwastewatersisconvertedtoeitherbiologicalsludgeorcarbondioxide.Becausethecarbonoriginatedinbiomass,theCO2emittedfromwastewatertreatmentisnotincludedinGHGinventories.Methaneandnitrousoxide,however,canalsobereleasedduringwastewatertreatment.Methane,inparticular,isanimportantemissionfromanaerobicwastewatertreatmentandsludgedigestionprocesses.MethaneandnitrousoxideareusuallyincludedinGHGinventories.TheWastesectionofthe1996RevisedGuidelinescontainsamethodforestimatingN2Oemissionsfrom“humansewage”(IPCC1997c,page6.28).ThatdiscussiondirectstheVersion1.1D-11July8,2005readertotheAgriculturesectionoftheManualformoreinformation.InthatsectionIPCCindicatesthatthreestudieshaveexaminednitrousoxideemissionsfromoperatingwastewatertreatmentfacilities(IPCC1997c,page4.110).AllthestudiesreportedlowN2Oemissions.Thus,inIPCC’smethodology“N2Oassociatedwithsewagetreatmentandlanddisposalisassumedtobenegligible,”anditisfurtherassumedthat“allsewagenitrogenentersriversand/orestuaries”whereaportionofitisconvertedintoN2O(IPCC1997c).Insummary,IPCC’sguidancecontainsmethodsforestimatingN2Oreleasedfromhumansewageonceitisdischarged,butassumesthatN2Oemissionsfromtreatmentplantsarenegligible.ThereisnodiscussionofN2Oemissionsfromwoodproductsorotherindustrialwastewatertreatmentplants.Methanefromwastewatertreatment,however,receivesmuchgreaterattentioninIPCC’sguidancedocuments.AdiagramintheIPCCGoodPracticedocumentshowswhichtypesoftreatmentprocesseshave“thepotentialforCH4emissions”(IPCC2000,page5.17).ThefigureindicatesthatallaerobictreatmentprocessesareoutsideofthescopeofIPCC’sguidelinesduetothelowpotentialformethanegeneration.Theguidelinesfocusonanaerobicwastewatertreatmentandanaerobicsludgedigestion.TheReferenceManualofIPCC’s1996RevisedGuidelinescontainsadiscussionofpulpandpaperindustrywastetreatmentoperations(IPCC1997c,page6.16):AssessmentofCH4productionpotentialfromindustrialwastewaterstreamsisbasedontheconcentrationofdegradableorganicmatterinthewastewater,thevolumeofwastewater,andthepropensityoftheindustrytotreattheirwastewaterinanaerobiclagoons.[emphasisadded]Usingthesecriteria,IPCCcitesworksuggestingthatpaperandpulpmanufacturersareamongthemostlikelytogeneratemethaneinwastewatertreatment(IPCC1997c).Boththepaperandpulpindustryandthemeatandpoultryprocessingindustriesproducelargevolumesofwastewaterthatcontainhighlevelsofdegradableorganics.Additionally,bothindustriesutilizelargefacilitiesthatoftenhavetheirownwastewaterhandlingsystems.Themeatandpoultryprocessingfacilitiescommonlyemployanaerobiclagoonstotreattheirwastewater,whilethepaperandpulpindustryisknowntouselagoons.IPCC’sapproachforestimatingmethanefromwastewatertreatmentorsludgedigestionissimilartotheall-in-one-yearmethodusedforestimatingmethaneemissionsfromlandfills.EmissionsarecalculatedusingEquation10:Methaneemissions=(TOWorTOS)xB0xMCF(Eq.10)where:TOWorTOS=measureoforganiccontentofanaerobicallytreatedwastewaterorsludgeB0=CH4perunitoforganicmatter,inunitsconsistentwithTOWorTOSMCF=fractionofmethanenotrecoveredorflared,variesfrom0to1dependingonthetreatmentunitD-12Version1.1July8,2005First,theamountofdegradablesubstratebeingfedtothetreatmentunitisdetermined.Thetotalorganic(chemicaloxygendemand,COD)inwastewaterisgiventhesymbolTOWwhilethetotalorganicinsludgeisgiventhesymbolTOS.TheIPCCreferencemanualcontainssomelimiteddatathatcanbeusedtoestimatepulpandpapermillwastewaterCOD,buttheyarenotincludedinthisreportbecausedataavailabletoindividualcompaniesareexpectedtobeoffargreaterquality(IPCC1997c).AfterdividingtheuntreatedwastewaterCODintoTOWandTOS,thetwostreamsarekeptseparateinsubsequentcalculations.LandfillcalculationsforsludgeareshowninSection1.2ofthisannex,whileemissionsfromsludgedigestionwouldbecalculatedusingEquation10.Incaseswheresludgeisburned,itisincludedinthecalculationsforGHGemissionsfrombiomassburning,discussedelsewhere.Forindustrialwastewaters,themaximummethaneproducingcapacityisgiventhesymbolB0andisexpressedinkgCH4/kgCOD.IPCC’s1996RevisedGuidelinesgiveadefaultvalueforB0of0.25kgCH4/kgCODforwastewaterandsludge.AfootnoteintheIPCCguidelinesexplainsthatbecausethedegradableorganicmatterinCODisthesamematerialthatismeasuredasdegradableBOD,thefactorB0willbe0.25kgCH4/kgCODorBOD.ThisisapproximatelytrueifthefactorsarebasedonBODorCODremoved,buttheGuidelinesdonotspecifythis,sayingonlythatTOWandTOSarethetotalorganiccontentsinindustrialwastewatersandsludges,respectively(IPCC1997c).TheIPCCGoodPracticedocumentchangesthe1996Guidelineswiththisexplanation(IPCC2000,page5.17):NotethatdegradablecarboninorganicwastecanbemeasureintermsofeitherBODorCOD.Fortypicaldomesticrawsewage,COD(mg/l)is2to2.5timeshigherthanBOD(mg/l).Therefore,itisimportanttouseemissionfactorsthatareconsistentwiththemeasureofdegradablecarbonbeingused.TheIPCCGuidelinesprovideonlyonedefaultvalueofB0thathastobeappliedtobothCODandBOD.ThisisnotconsistentwiththeobserveddifferencesbetweenBODandCODlevelsinrawsewage.GiventhedifferencesintheamountofBODandCODinwastewaterthiscanresultinestimatesofdifferentemissionslevelsfromthesameamountofwastewaterdependingonwhichmeasureisused.Toensurethattheresultingemissionestimatefromagivenamountofwastewateristhesameregardlessofthemeasureoforganiccarbonused,theCOD-basedvalueofB0shouldbeconvertedintoaBOD-basedvalueviaup-scalingwithadefaultfactorof2.5.Thus,itisgoodpracticetouseadefaultvalueof0.25kgCH4/kgCODoradefaultvalueof0.6kgCH4/kgBOD.Theimportantpointisthatthebasisforthefactorsmustmatchthemeasureoforganiccontentofthewaste.Inparticular,oneneedstoknowwhetherthefactorsareforBODorCODandwhethertheyarebasedontheorganiccontentoftheuntreatedwastewaterortheorganiccontentremovedduringtreatment.Amethaneconversionfactor(MCF)isagainusedtorepresentthemethanegenerationpotentialrelativetoareferencesystem.Inthiscase,therearetworeferencesystems.TheMCFforcompletelyaerobicsystemsis0.0,whiletheMCFforcompletelyanaerobicsystemsis1.0.AlthoughtheReferenceManualshowsdefaultMCFsforvariouscountries,IPCCVersion1.1D-13July8,2005suggeststhatexpertsbeconsultedindeterminingappropriatevaluesforMCF(IPCC1997c).Inthisreview,nopublishedvaluesofMCFforaerobicorfacultativetreatmentsystemswerefound.3.2Canada–CanadianGHGChallengeRegistryGuidetoEntity-andFacility-BasedReporting,Canada’sClimateChangeVoluntaryChallengeandRegistryandCanada’sGreenhouseGasInventory1990-2000TheVCR(2004)guidancedoesnotspecificallyincludeemissionsfromwastemanagementactivities.Theseemissionsareincluded,however,inCanada’sGreenhouseGasInventory,1990-2002(EnvironmentCanada2004).CanadadoesnotcountCO2producedbythedecompositionofbiomasscarbon.EstimatesaremadeforCH4andN2Oemissions,however(EnvironmentCanada2004).3.2.1LandfillsBecausethecharacterofCanada’slandfillshasbeenchangingovertime,CanadausestheSchollCanyonmodel(firstorderdecaymodel)forestimatingmethaneemissionsfromlandfills.Thisallowsvaryingamountsofwastetobedepositedeveryyearandalsoallowsthedecayratetovaryaccordingtomanagementpracticesandotherfactors.ThisisoneoftheoptionsdescribedintheIPCC1996RevisedGuidelinesandtheMay2000IPCCGoodPracticesdocument.ThedescriptionhereinhighlightsonlythoseaspectsoftheCanadianapproachthateitherinvolveCanada-specificparametervaluesorrepresentdeparturesfromtheIPCCapproach(EnvironmentCanada2004).BecauseofthelargesizeoftheforestproductsindustryinCanada,thegovernmentdevelopedseparateestimatesofmethaneemissionsfromwoodwastelandfills.AfterevaluatingtherecommendationsdevelopedbyCanadianexpertsforkvaluestomodelmunicipalsolidwaste(MSW)landfills,thegovernmentdecidedtousethelowestkvalueforMSWinthemajorforestindustryprovincestoestimateemissionsfromwoodwastelandfills.Thiskwas0.01/yr.TheCanadiangovernmentconsideredthedegradablecarboncontentofwoodwasteandassumedthatwoodwastelandfillgaswouldconsistof50%methanetocalculateamethanegenerationpotential(L0)forwoodwasteof118kgCH4/tonneofwoodwaste(EnvironmentCanada2004).3.2.2WastewaterTreatmentandSludgeDigestionCanadaestimatedGHGemissionsonlyfrommunicipalwastewatertreatmentduetolackofdataontreatmentofindustrialwastewater(EnvironmentCanada2004).Methaneemissionsfromaerobicsystemswereassumedtobenegligible,anassumptionconsistentwithIPCC’sguidance.EmissionsfromanaerobicsystemswereestimatedusinganapproachdevelopedbyOrtechInternationalforEnvironmentCanadain1994.Usingthisapproach,itwasestimatedthat4.015kgCH4/person/yearcouldpotentiallybeemittedfromwastewatertreatedanaerobically(EnvironmentCanada2004).ThisfactorwasmultipliedbythenumberofpersonsineachprovinceandthefractionofthewastewatertreatedD-14Version1.1July8,2005anaerobicallyineachprovincetoestimatemethaneemissionsfromtheanaerobictreatmentofmunicipalwastewater.CanadausedtheIPCCdefaultmethodologyforestimatingN2Oemissionsfromhumansewage.TheIPCCmethodologyassumesthat(a)negligibleamountsofN2Oarereleasedduringtreatment;and(b)allofthenitrogeninuntreatedhumansewageisdischargedtoriversorestuaries,whereaportionofthenitrogenisconvertedtoN2O(EnvironmentCanada2004).3.3Finland–GreenhouseGasEmissionsandRemovalsinFinland3.3.1LandfillsTheFinnishgovernment’sestimatesarebasedonIPCC’sall-in-one-yeardefaultmethod(IPCC1997c)through2001.TheparametervalueshavebeenselectedtorepresentconditionsinFinland(TechnicalResearchCenterofFinland2001).Theparametervaluesneededtoestimateemissionsfrompulpandpapermilllandfillsareshownbelow.ThedescriptionoftheIPCCall-in-one-yearapproachcontainsmoreinformationonthevariablesandcalculations.Methanereleasedperyear=([wastedisposedperyearxDOCxDOCfxMCFxFx16/12]–R)-(1-OX)(Eq.12)DOC=weightfractiondegradableorganiccarboninwaste(variesbywastetypeasshownbelow;althoughnotspecified,thevaluesforDOCstronglysuggestthatligninisincluded)=0.4forpaperandcardboard,wetweightbasis=0.3forwoodandbark,wetweightbasis=0.1fordeinkingwaste,wetwastebasis(definitionisuncertainbecausedeinkingsludgeislistedseparately)=0.45forestindustrysludge–unspecified,dryweightbasis(assumed30%solids)=0.3deinkingsludge,dryweightbasis(assumed30%solids)=0.3forestindustryfibersludge,dryweightbasis(assumed30%solids)DOCf=0.5(fractionofdegradableorganiccarbondegradedtolandfillgas;IPCC’s1996RevisedGuidelinessuggestadefaultof0.77,buttheMay2000GoodPracticesdocumentrevisedthisdefaultvalueto0.5to0.6forDOCfincaseswheretheligninisincludedintheDOC;Finlanduses0.5toreflectthelowtemperatureandless-than-optimalconditionsfordecompositioninFinnishlandfills)MCF=0.7(essentiallythelandfill’smethanegenerationpotentialrelativetoa“managed”landfill;FinlandassumesthathalfofwastegoestosmalllandfillswithMCF=0.4andtherestgoestolargelandfillswithMCF=1)F=0.5(fractionoflandfillgasthatismethane;IPCCdefaultassumesthatlandfillgasis50%methane)Version1.1D-15July8,200516/12=factortoconvertfromcarbontomethaneR=amountoflandfillmethanerecovered;valuevariesfromyeartoyearOX=0.1(10%ofmethanethatisnotrecoveredisoxidizedtoCO2intheupperlayersofthelandfillcover)Initsmostrecentnationalinventory,FinlandusedtheTier2methodofIPCC(FinlandMinistryoftheEnvironment2004).Inthe1990-2002inventory,FinlandMinistryoftheEnvironmentprovidedkvaluesfordifferentwastes:k1=0.2(foodwasteinMSWandsludges)k2=0.03(woodwasteinMSWandinconstructionanddemolitionwaste,paperwastecontaininglignininMSW)k3=0.05(industrialsolidwasteandotherfractionsofMSWthanabove)3.3.2WastewaterTreatmentandSludgeDigestionFinlandusesIPCC’sdefaultmethodologytoestimatemethaneemissionsfromwastewatertreatment(FinlandMinistryoftheEnvironment2004).EmissionsofCH4=OrganicloadxB0xMCF(Eq.13)where:Organicloadisexpressed(inFinland’scase)asCODinindustrialwastewatersandBODindomesticwastewaters.B0=themaximummethanegenerationpotential–FinlandusesthedefaultvaluegivenintheIPCC1996RevisedGuidelinesof0.25kgCH4/kgCODorBOD.IPCC’sMay2000GoodPracticesdocumentrevisedthedefaultvalueto0.25kgCH4/kgCODand0.6kgCH4/kgBOD.MCF=aweightedaveragevaluereflectingthemethanegenerationpotentialofthetreatmentplantsinFinlandrelativetoananaerobictreatmentplant.FinlandusedanMCFof0.01fordomesticwastewaters,and0.005forindustrialwastewaters.EmissionsofN2OareestimatedaccordingtoIPCC’sRevised1996Guidelines,exceptthatFinlandexpandsthescopetoincludenitrogendischargednotonlyindomesticsewage,butinindustrialwastewatersandfishfarmwastes(FinlandMinistryoftheEnvironment2004).TheIPCCmethodestimatestheN2Oreleasedfromwastewateronceitisdischarged,butassumesthatN2Oemissionsfromthetreatmentplantsarenegligible.3.4Japan–InformationfromtheJapanPaperAssociation3.4.1LandfillsInpreparingnationalinventoriesforgreenhousegases,theMinistryofEnvironmentincludesmethaneandnitrousoxidefromlandfillscontaining“paperwaste,”assumedtobesludgesandotherprocesswastesfrompulpandpapermanufacturing(JPA2001).Theemissionfactorsare:D-16Version1.1July8,2005Methane=151kg/tonpaperwasteNitrousOxide=0.01kg/tonpaperwaste3.5Sweden–Sweden’sNationalInventoryReport20043.5.1LandfillsInSweden’sNationalInventoryReport2004,SwedenusedanapproachverysimilartoIPCC’sfirstorderdecayapproachtoestimatemethaneemissionsfromlandfills.Wastelandfilledin1952andafterisincludedintheanalysis.ThetimefactorintherateequationisadjustedslightlytocorrespondtoanassumptionthatallwasteislandfilledonJuly1ofeachyear.Inaddition,Swedenhasdevelopedcountry-specificvaluesforanumberoftheparametersusedinthemodel(SwedishEPA2004).TheSwedishgovernmenthasexaminedmethanegenerationfrompulpmillsludgelandfills.Itusesavalueof45kgCH4/tonofwastetorepresentthemethanegenerationpotentialforlandfilledpulpmillsludge(SwedishEPA2004).Theothervaluesusedinthefirstordermodelformethaneemissionsfromlandfillsareasfollows(SwedishEPA2004):MCFbefore1980=0.6MCFin1980andafter=1.0F(fractionofmethaneinlandfillgas)=0.5DOCf(fractionofdegradableorganiccarbondegradedtolandfillgas)=0.7OX(fractionofnon-collectedgasoxidizedinsurfacelayersofthelandfill)=0.1t1/2(half-lifeofthemethanogenesis)=7.5yearsk(firstorderrateconstantassumingahalf-lifeof7.5years)=0.092/yr3.5.2WastewaterTreatmentandSludgeDigestionTheSwedishNationalInventoryReportindicatesthat“[n]ationalactivitydataonnitrogenindischargedwastewaterisused,incombinationwithamodelestimatingnitrogeninhumansewagefrompeoplenotconnectedtomunicipalwastewatertreatmentplants”(SwedishEPA2004).Theformulausedtoestimatenitrousoxideemissionsfromnitrogenindischargedwastewaterincludestermsfordataassociatedwithmunicipalwastewatertreatmentplants,industrialtreatmentplants,andsmalltreatmentplantsforwhichdatawerenotavailable(thislasttermincorporatesassumptionsassociatedwiththenumberofpeopleconnectedtosmalltreatmentplantsandnitrogenconsumptionbythesepeople).TheIPCCdefaultfactorforconversionofnitrogentonitrousoxideisused.Sludge-relatedemissionsofmethanefromlandfillswereestimatedasexplainedabove.GHGemissionsfromanaerobicsludgedigestionwerenotdiscussed,althoughthereportnotedthatthelandfillgaspotentialofalreadydigestedsludgewasreducedby50%(SwedishEPA2004).Version1.1D-17July8,20053.6UnitedStates–EPAInventoryofUSGreenhouseGasEmissionsandSinks:1990-2002andAnthropogenicMethaneEmissionsintheUnitedStates:Estimatesfor1990,ReporttoCongress3.6.1LandfillsEPA’sanalysisofGHGemissionsfromlandfillsisfocusedonmethanefrommunicipalsolidwastelandfills,althoughestimatesarealsogivenforindustriallandfillemissionsofmethane.ThisdescriptionofthemethodologyistakenfromEPA’sInventoryofU.S.GreenhouseGasEmissionsandSinks:1990-2002(USEPA2004,p.231):MethaneemissionsfromlandfillswereestimatedtoequaltheCH4producedfrommunicipallandfills,minustheCH4recoveredandcombusted,plustheCH4producedbyindustriallandfills,minustheCH4oxidizedbeforebeingreleasedintotheatmosphere.ThemethodologyforestimatingCH4emissionsfrommunicipallandfillsisbasedonamodelthatupdatesthepopulationofU.S.landfillseachyear.Thismodelisbasedonthepatternofactualwastedisposal,asevidencedinanextensivelandfillsurveybytheEPA’sOfficeofSolidWastein1986.Asecondmodelwasemployedtoestimateemissionsfromthelandfillpopulation.[ThismodelisdescribedinUSEPA1993.]Foreachlandfillinthedataset,theamountofwastein-placecontributingtoCH4generationwasestimatedusingitsyearofopening,itswasteacceptancerate,yearofclosure,anddesigncapacity.Dataonnationalmunicipalwastelandfilledeachyearwasapportionedbylandfill.Emissionsfrommunicipallandfillswerethenestimatedbymultiplyingthequantityofwastecontributingtoemissionsbyemissionfactors…Theestimatedlandfillgasrecoveredperyearwasbasedonupdateddatacollectedfromvendorsofflaringequipmentandadatabaseoflandfillgas-to-energy(LFGTE)projectscompiledbyEPA’sLandfillMethaneOutreachProgram(LMOP)….EmissionsfromindustriallandfillswereassumedtobeequaltosevenpercentofthetotalCH4emissionsfrommunicipallandfills.TheamountofCH4oxidizedbythelandfillcoveratbothmunicipalandindustriallandfillswasassumedtobetenpercentoftheCH4generatedthatisnotrecovered.TocalculatenetCH4emissions,bothCH4recoveredandCH4oxidizedweresubtractedfromCH4generatedatmunicipalandindustriallandfills.ThemodeldescribedinAnthropogenicMethaneEmissionsintheUnitedStates:Estimatesfor1990,ReporttoCongress,isatwoparametermodelforMSWlandfills(USEPA1993).Itisbasedonanempiricalanalysisofgasgenerationdatafrommorethan85USMSWlandfillsandestimatesmethanegenerationbasedonthemassofwasteinplaceandambientrainfall.EPAalsohasamodel,however,thatisequivalenttothefirstorderdecaymodelsuggestedbyIPCC.EPA’sfirstordermodelisdescribedinitscompilationofemissionfactors,AP-42(USEPA1998d).EPAcallsitsmodeltheLandfillAirEmissionsEstimationModel(LAEEM).NCASIhasreviewedEPA’snormalapproachforestimatingmethaneemissionsD-18Version1.1July8,2005fromlandfillsandtheresultsarereportedinNCASITechnicalBulletinNo.790(NCASI1999).Thematerialhereinistakenprimarilyfromthatsource.LAEEMisaPC-basedautomatedestimationtool,operatinginaWindows™environment,forcalculatinguncontrolledairemissionsfrommunicipalsolidwaste(MSW)landfills,availablefromtheEPAOfficeofAirQualityPlanningandStandards.LAEEMincorporatestheSchollCanyonmodel,afirstorder,singlestagemodelidenticaltoIPCC’s.Kineticratecoefficientswereempiricallyadjustedtoreflectchangesinrefusemoisturecontentandotherlandfillconditions.TheSchollCanyonmodelassumesthatthegasproductionrateisatitspeakuponinitialwasteplacementandthatanaerobicconditionsareestablishedimmediately.Gasproductionisthenassumedtodecreaseexponentiallyasafirstorderdecay.Themodelallowsfordivisionofthelandfillintomodules(annualrefuseaccumulations)toaccountfordifferentagesofrefuseaccumulatedovertime.Adefaultfirstorderrateconstantformethanegeneration(k)of0.04/yrisrecommendedforareasreceiving25inchesormoreofrainperyear,whileavalueof0.02/yrisrecommendedfordrierareas.Adefaultvalueformethanegenerationpotential(L0)of100m3methane/Mgwasteisrecommended(USEPA1998d).AnexaminationofthesourceoftheserecommendationsbyNCASIledtotheconclusionthatEPA’sdefaultvalues(derivedfromstudiesofMSWlandfills)areprobablytoohighforwoodproductsindustrylandfills(NCASI1999).3.6.2WastewaterTreatmentandAnaerobicSludgeDigestionInpriorinventories(e.g.,thatdiscussedinUSEPA2001a)EPAindicatedthatitusedtheIPCCmethodologyforestimatingmethaneemissionsfromwastewatertreatment.Thisinvolvedestimatingtheamountofwastewaterorganicmatterproducedandmultiplyingthatamountbyanemissionfactor.InthesepriorinventoriesEPAestimatedmethaneemissionsonlyfromanaerobictreatmentoperations,whichwereassumedtobehandling15%ofthedomesticwastewaterBODgeneratedintheUS(USEPA2001a).InitsmostrecentinventoryEPAestimatedindustrywastewatertreatmentemissionsusingadifferentmethodology.ThefollowingdescriptionofthatmethodologyistakenfromEPA’sInventoryofU.S.GreenhouseGasEmissionsandSinks:1990-2002(USEPA2004,page235),andisstatedbyEPAtobeconsistentwiththemethodologydescribedbyIPCC(2000):Methaneemissions…wereestimatedbymultiplyingtheannualproductoutput(metrictons/year)bytheaverageoutflow(m3/tonofoutput),theorganicsloadingintheoutflow(gramsoforganicCOD/m3),theemissionfactor(gramsCH4/gramsCOD),andthepercentageoforganicCODassumedtodegradeanaerobically.Indevelopingestimatesforthepulpandpapercategory,BODwasusedinsteadofCOD,becausemoreaccurateBODnumberswereavailable.Theemissionfactorusedforpulpandpaperwastewaterwas0.6kgCH4/kgBOD5…(hereEPAcitesIPCC2000).Wastewatertreatmentforthepulpandpaperindustrytypicallyincludesneutralization,screening,sedimentation,andflotation/hydrocycloningtoremovesolids.Themostimportantstepislagooningforstorage,settling,andbiologicalVersion1.1D-19July8,2005treatment(secondarytreatment).Indeterminingthepercentthatdegradedanaerobically,bothprimaryandsecondarytreatmentwereconsidered.Primarytreatmentlagoonsareaeratedtoreduceanaerobicactivity.However,thelagoonsarelargeandzonesofanaerobicactivitymayoccur.Approximately42percentoftheBODpassesontosecondarytreatment,whicharelesslikelytobeaerated(EPA1993).Itwasassumedthat25percentoftheBODinsecondarytreatmentlagoonsdegradesanaerobically,while10percentpassesthroughtobedischargedwiththeeffluent(hereEPAcitesthe1997publicationEPA-600/R-97-091).Overall,thepercentageofwastewaterorganicsthatdegradeanaerobicallywasdeterminedtobe10.3percent…TherearepotentiallysignificantdifferencesbetweentheIPCC(2000)guidancecitedbyEPAandthemethodologydevelopedbyEPAfromthatguidance.TheIPCCguidancerecommendsmultiplyingthequantityoforganicmaterialintheeffluentbythe“maximummethaneproducingcapacity”(0.6lbCH4perlbBOD)andthenbythe“fractionofwastetreatedanaerobically”[emphasisadded],whereastheEPAmethodologyistomultiplythequantityoforganicmaterialbythe“emissionfactor”(0.6lbCH4perlbBOD)andthenbythe“percentageoforganic[BOD]assumedtodegradeanaerobically”[emphasisadded].FromthisassessmentitisclearthatwheretheIPCCrecognizesapotentialformethaneformationfromanaerobicdecompositionoforganicmatter,EPAassignsanemissionfactorthatisequivalenttothismaximumpotential.Furthermore,whereIPCCrecommendsassessingthefractionofwastethatisactuallytreatedanaerobically,EPAassumesanamountoforganicmaterialinthewastestreamthatisdegradedanaerobically,regardlessofthewastetreatmenttechnologyapplied.3.7WRI/WBCSD–TheGreenhouseGasProtocol,October2001TheWRI/WBCSDProtocol(WRI2001,2004a)dividesGHGemissionsfromwastemanagementintothosefromcompany-ownedsources(includedinScope1oftheWRI/WBCSDProtocol)andthosefromsourcesownedbyotherentities(includedinScope3).Version1.1E-1July8,2005ANNEXECARBONDIOXIDEFROMBIOMASSCOMBUSTION1.0ESTIMATESOFCO2EMISSIONSFROMBIOMASSCOMBUSTIONPulpandpapermillsgenerateapproximatelytwothirdsoftheirenergyneedsfrombiomassfuelsrecoveredfromtheindustry’swasteandprocessstreams.Energy-richbiomass–derivedfromwoodchips,bark,sawdust,andpulpingliquorsrecoveredfromtheharvestingandmanufacturingprocesses–isatmosphericcarbondioxidesequesteredbytreesduringgrowthandtransformedintoorganiccarbonsubstances.Whenthesebiomassfuelsareburned,theCO2emittedduringthemanufacturingandcombustionprocessesistheatmosphericcarbondioxidethatwassequesteredduringgrowthofthetree;hence,thereisnonetcontributiontotheatmosphericCO2level.Thiscarboncycleisaclosed-loop.Newtreegrowthkeepsabsorbingatmosphericcarbondioxideandmaintainsthecycle.Anyincreasesordecreasesintheamountofcarbonsequesteredbytheforestsareaccountedforinthecomprehensiveforestaccountingsystem.ThisistheapproachgenerallyprescribedfornationalinventoriesbytheUnitedNationsFrameworkConventiononClimateChange.MostinternationalprotocolsincludingthatoftheIntergovernmentalPanelonClimateChange(IPCC)haveadoptedtheconventionsetoutbytheUnitedNations.TheIPCChasstatedthatemissionsfrombiomassdonotaddtoatmosphericconcentrationsofcarbondioxide(IPCC1997a).1.1EstimatedBiomassEmissionsTheinformationonbiomassemissionsreportedhereinisbeingsupplied:•Toensurethatreadersunderstandtheentity’soverallenergyprofileintermsofbothgreenhousegasemissionsandnon-greenhousegasemissions,and•Toprovideawarenessandunderstandingofhowbiomassfuelsaregeneratedandusedinthemanufactureofpulpandpaper.TablesE1throughE3canbeusedtoestimateemissionsofCO2frombiomasscombustionandTableE4canbeusedtorecordtheresults.NotethatthisinformationisinconformancewiththegeneralgreenhousegasprotocoldesignedbytheWorldResourcesInstituteandtheWorldBusinessCouncilforSustainableDevelopment(WRI2001,2004a).Usersofthesecalculationtoolsmayelecttomodifytheformatandtypeofinformationpresentedbasedonspecificfacilityorcompanyneeds.TableE1.EstimatingEmissionsofBiomass-DerivedCO2fromCombustionofWood,Bark,andotherBiomassFuels(exceptpulpingliquors,whichareaddressedinTableE2)Step1Step2Step3ABCDEFQuantityoffuelburnedUnitusedtomeasurequantityoffueluse[Note:BecarefulnottomixHHVsandLHVs.]CO2emissionfactor:[defaultvalueis:solidbiomass:109kgCO2/GJLHV]UnitofCO2emissionfactorCO2emissionsinkgCO2/yrCO2emissionsinmetrictonsCarbon/yrSourceDescriptionFuelTypeE=ACF=E12/44/1000Example:BarkBoilerBark500,000GJ(LHV)109kgCO2/GJLHV54,500,00014,900BiomassCarbonReleasedasCO2fromCombustionofWood,Bark,orotherbiomass(exceptpulpingliquorswhichareaddressedinTable2below)Amountofbiomass-derivedCO2includedinabovenumberthatisexported(e.g.,toPCCplant)ratherthanbeingemitted-OptionalinformationEmissionfactorforsolidbiomassfromIntergovernmentalPanelonClimateChange(IPCC).1997.Revised1996IPCCGuidelinesforNationalGreenhouseGasInventories:ReferenceManual(Volume3).Table1.1,correctedfor1%unburnedcarbon(USEPA2001b)NOTE:AlllistedemissionfactorsarebasedonLHV,assumedtobe95%ofHHVforbiomassfuelsTableE2.EstimatingEmissionsofBiomass-DerivedCO2fromPulpingLiquorsandKraftMillLimeRecoveryNotethatbecausetheemissionfactorsforspentpulpingliquorsarebasedonthecarboncontentoftheliquors(assumingaone-percentcorrectionforunoxidizedcarbon),theliquoremissionfactorwillincludeanycarbonexitingwithsmeltfromarecoveryfurnace.Therefore,forkraftmills,theliquoremissionfactorsestimatebiomasscarbonemissionsfromboththerecoveryfurnaceandfromthelimekiln.Companieshavetheoptionofestimatingtheamountsofbiomass-derivedCO2thatisexportedratherthanbeingreturnedtotheatmosphere.Iftheexportsarefromalimekilnorcalcinerwherefossilfuelsarebeingused,asageneralapproximationtheexportsofbiomass-derivedCO2willbetwicetheexportsoffossilfuel-derivedCO2(see"CO2ImportsandExports"worksheet).Whereexportsconsistofgasesfromalimekilnorcalcinerthatisburningonlybiomassfuels,alloftheexportsarebiomass-derivedCO2.Step1Step2Step3ABCDEFQuantityoffuelburnedUnitusedtomeasurequantityoffueluse[Note:BecarefulnottomixHHVsandLHVs.]CO2emissionfactors:[defaultvaluesarelistedinTableE3below;kgCO2/GJLHV]UnitofCO2emissionfactorCO2emissionsinkgCO2/yrCO2emissionsinmetrictonsCarbon/yrSourceDescriptionFuelTypeE=ACF=E12/44/1000Example:RecoveryFurnaceKraftPulpingLiquor,NorthAmericanSW100,000GJ(LHV)94.2kgCO2/GJLHV9,420,0002,570BiomasscarboninpulpingliquorsreleasedasCO2fromtherecoveryfurnaceandlimekilnorcalcinerAmountofbiomass-derivedCO2includedinabovenumberthatisexported(e.g.,toPCCplant)ratherthanbeingemitted-optionalinformationNOTE:AlllistedemissionfactorsarebasedonLHV,assumedtobe95%ofHHVforbiomassfuelsTableE3.SuggestedPulpingLiquorDefaultEmissionFactorsforBiomass-DerivedCO2(includesemissionsfromboththerecoveryfurnaceandlimekiln/calciner)TypeofPulpingLiquorWoodFurnishTypicalCarbonContent[percent,drybasis]TypicalEnergyContent–HHV[GJHHV/metrictondrysolids]CalculatedEnergyContent-LHV[GJLHV/metrictondrysolids]Biomass-DerivedCO2EmissionFactor[kgCO2/GJLHV]KraftblackliquorScandinavianSoftwood3514.213.594.2KraftblackliquorScandinavianHardwood32.513.512.892.0KraftblackliquorNorthAmericanSoftwood3514.213.594.2KraftblackliquorNorthAmericanHardwood3413.913.293.5KraftblackliquorTropicalEucalyptus34.8KraftblackliquorTropicalMixedWoods35.214.113.495.4KraftblackliquorBagasse36.914.814.195.3KraftblackliquorBamboo34.514.113.493.5KraftblackliquorStraw36.514.714.094.9Semi-ChemicaltobedeterminedSulfitetobedeterminedKraftblackliquordefaultemissionfactorsarebasedonthecarboncontentoftheliquors(assumingaone-percentcorrectionforunoxidizedcarbon)andincludeanycarbonexitingwithsmeltfromarecoveryfurnace.Therefore,forkraftmills,theliquoremissionfactorsestimatebiomasscarbonemissionsfromboththerecoveryfurnaceandfromthelimekiln.Factorsobtainedfrom:Chapter1-ChemicalRecovery,byEsaVakkilainen.1999.In:PapermakingScienceandTechnology,Book6B:ChemicalPulping.Gullichsen,J.,andPaulapuro,H.(eds.).Helsinki,Finland:FapetOyVersion1.1E-5July8,2005TableE4.EmissionsofBiomass-DerivedCO2Write“NA”toshowanitemisnotapplicable.Whereemissionshavebeendeterminedtobeinsignificantornon-material,write“NM”andexplainthebasisforthedeterminationinafootnote.EmissionsofBiomass-DerivedCO2(metrictones)1Biomass-fueledboilers(fromTableE1inAnnexE)2Pulpingliquor-derivedCO2(fromTableE2inAnnexE)3TotalEmissionsofBiomass-DerivedCO2(Sumofline1and2)Explainthemethodusedtodetermineownershipofemissionsfromsourcesnotcompletelyownedbythecompany.UsetheWRI/WBCSDGHGProtocolforguidanceondeterminingownership.Includeanyotherinformationthatisneededtounderstandtheinventoryresults:Version1.1F-1July8,2005ANNEXFTABLESOFGREENHOUSEGASEMISSIONFACTORSThesetablesarecopiedfromthemainbodyofthisreport.Tablenumbersareconsistentwithnumberinginthemaintext.Table2.IPCCDefaultCO2EmissionFactorsforFossilFuels(afterIPCC1997b)FossilFuelUncorrectedEmissionFactorkgCO2/TJCorrectedEmissionFactorkgCO2/TJCrudeoil73,30072,600Gasoline69,30068,600Kerosene71,90071,200Dieseloil74,10073,400Residualfueloil77,40076,600LPG63,10062,500Petroleumcoke100,80099,800Anthracitecoal98,30096,300Bituminouscoal94,60092,700Sub-bituminouscoal96,10094,200Lignite101,20099,200Peat106,000104,900Naturalgas56,10055,900Thesefactorsassumenounoxidizedcarbon.Toaccountforunoxidizedcarbon,IPCCsuggestsmultiplyingbythesedefaultfactors:coal=0.98,oil=0.99,andgas=0.995.Table3.RecommendedCorrectionFactorsforUnoxidizedCarbonfromVariousGuidanceDocumentsSourceCoalOilNaturalGasIPCC(1997c)98%99%99.5%EnvironmentCanada(2004)99%99%99.5%EPAClimateLeaders(USEPA2003)99%99%99.5%DOE1605b(USDOE1994)99%99%99%EPAAP-42(USEPA1996,1998a,b,c)99%99%99.9%TheemissionfactorspresentedinVCR(2004)donotspecifycorrectionfactorsforunoxidizedcarbon,howeverallemissionfactorspresentedinVCR(2004)aredrawnfromEnvironmentCanada2004F-2Version1.1July8,2005Table4.IPCCTier1CH4andN2OEmissionFactorsforStationaryCombustion(fromIPCC1997c)CH4EmissionFactorskg/TJN2OEmissionFactorskg/TJCoal101.4Naturalgas50.1Oil20.6Wood/woodresiduals304Table5.IPCCTier2UncontrolledCH4andN2OEmissionFactorsforIndustrialBoilers(IPCC1997c)FuelTechnologyConfigurationkgCH4/TJkgN2O/TJBituminouscoalOverfeedstokerboilers1.01.6Sub-bituminouscoalOverfeedstokerboilers1.01.6BituminouscoalUnderfeedstokerboilers141.6Sub-bituminouscoalUnderfeedstokerboilers141.6BituminouscoalPulverizedDrybottom,wallfired0.71.6BituminouscoalPulverizedDrybottom,tang.fired0.70.5BituminouscoalPulverizedWetbottom0.91.6BituminouscoalSpreaderStoker1.01.6BituminouscoalFluidizedbedCirculatingorbubbling1.096Sub-bituminouscoalFluidizedbedCirculatingorbubbling1.096Anthracite101.4Residualoil3.00.3Distillateoil0.20.4NaturalgasBoilers1.40.1NaturalgasTurbines0.60.1NaturalgasInt.comb.engine2-cycleleanburn170.1NaturalgasInt.comb.engine4-cycleleanburn130.1NaturalgasInt.comb.engine4-cyclerichburn2.90.1TheseareIPCCTier1genericemissionfactorsforcoalandnaturalgas.Tier2emissionfactorsarenotavailable.Version1.1F-3July8,2005Table6.EmissionFactorsforKraftMillLimeKilnsandCalcinersEmissions,kg/TJFuelKraftmilllimekilnsKraftmillcalcinersCO2CH4N2OCO2CH4N2OResidualoil76,6002.7θ0χ76,6002.7θ0.3φDistillateoil73,4002.7θ0χ73,4002.7θ0.4φNaturalgas55,9002.7θ0χ55,9002.7θ0.1φBiogas02.7θ0χ02.7θ0.1δfromTable2,correctedforunburnedcarbonθfromNCASI1980χbasedonIPCCdescriptionoftemperaturesgivingrisetoN2OemissionsφfromTable5δassumedappropriatetousetheemissionfactorfornaturalgas,asthecompositionandcombustionconditionsforbiogasaremoresimilartonaturalgasthantootherfuelsTable7.EmissionsfromCalcium-andSodium-CarbonateMake-upinthePulpMillEmissionsPulpmillmake-upCaCO3440kgCO2/tCaCO3Pulpmillmake-upNa2CO3415kgCO2/tNa2CO3ifcarbonateisderivedfrombiomass,GHGemissionsarezeroF-4Version1.1July8,2005Table8.EmissionFactorsforCH4andN2OfromBiomassCombustionEmissionFactorDescriptionkgCH4/TJkgN2O/TJReferenceWoodwaste-firedboilersWood,woodwaste,andotherbiomassandwastes304Tier1–IPCC1997cUncontrolledemissionsfromwood-firedstokerboilers15-Tier2–IPCC1997cAverageforwoodresiduecombustion9.55.9USEPA2001Averageforcirculatingfluidizedbedboilersburningpeatorbark18.8Fortum2001Averageforbubblingfluidizedbedboilersburningpeatorbark2<2Fortum2001Pre-1980woodresidue-firedstokerboilerssampledaheadofcontroldevices8.2-NCASI1980Pre-1980woodresidue-firedstokerboilerssampledafterwetscrubbers2.7-NCASI1985Woodfiredboiler41λ3.1λJPA2002Woodasfuel24λ3.4λAEATech.2001Woodwaste305SwedishEPA2004Medianemissionfactorsforwoodwaste1241–401.4–75EEA2004RecoveryfurnacesRecoveryfurnace<1<1Fortum2001Recoveryfurnace–blackliquor2.5Ω-JPA2002BlackLiquor305SwedishEPA2004Medianemissionfactorsforblackliquor2.521–17.71–21.4EEA2004convertedfromGCVtoNCVassuminga5%differenceexcludesoneveryhighnumberassociatedwithlowoxygen-highcarbonmonoxideconditionsλbasedonheatcontentof20GJ/tdrysolidsΩbasedonliquorheatcontentof13.3GJ/tdrysolidsVersion1.1F-5July8,2005Table9.EmissionFactorsforNon-RoadMobileSourcesandMachinery(IPCC1997c)(IPCCRevised1996GuidelinestakenfromEMEP/CORINAIR)SourceandEngineTypeCO2kg/TJCH4kg/TJN2Okg/TJCO2-equiv.kg/TJForestry–diesel73,40043082,800Industry–diesel73,40043082,800Railways–diesel73,40043082,800Inlandwaterway–diesel73,40043082,800Marine–diesel73,4007274,200Industry–gasoline4-stroke68,60050270,300Forestry–gasoline2-stroke68,6001700.472,300Industry–gasoline2-stroke68,6001300.471,500Inlandwaterway–gasoline4-stroke68,60040270,100Inlandwaterway–gasoline2-stroke68,6001100.471,000fromTable2,correctedforunburnedcarbonVersion1.1G-1July8,2005ANNEXGSUMMARYOFSIGNIFICANTREVISIONSTOVERSION1.0Thisreport,CalculationToolsforEstimatingGreenhouseGasEmissionsfromPulpandPaperMills,Version1.1,isthefirstmajorrevisionoftheoriginalversionofthereportwhichwaspublishedinlate2001.Therevisionwasundertakenforseveralreasons:•Correctminorerrorsintheoriginalversion•ReflectnewguidanceprovidedintheMarch2004RevisedEditionoftheGHGProtocol(WRI2004a)•ReflectnewguidancecontainedinnationalguidancedocumentsThisannexprovidesasummaryofthesignificantchangesmadetothereport.Changesinthewordingandorganizationofthereport,madesolelytoenhanceclarity,willnotbereflectedinthisannex.Onlymaterialchangesareincludedherein.ExecutiveSummaryThewordingwasmodifiedtohelpclarifythedifferencebetweenorganizationalboundariesandoperationalboundaries.Section1TheClimateLeadersGreenhouseGasInventoryProtocolCoreModuleGuidanceissuedbytheUnitedStatesEnvironmentalProtectionAgency(USEPA)andtheCanadianGHGChallengeRegistry,GuidetoEntity&Facility-BasedReportingissuedbytheVoluntaryChallengeandRegistry(VCR)wereaddedasexamplesof“acceptedGHGprotocols”thatthepulpandpapertoolsareintendedtobeusedwith.ThesetwoprotocolswerealsoidentifiedinSection3.TheGHGprotocoldevelopedbyGeorgia-PacificCorporationisreferredtoasanexampleofhowonecompanydevelopedaprotocolspecifictotheforestproductsindustry(GP2002).Section3TheToolforCalculatingHFCandPFCEmissionsfromtheManufacturing,Installation,OperationandDisposalofRefrigerationandAir-conditioningEquipment,Version1.0,currentlybeingdevelopedbyWRI/WBCSD,wasidentifiedasaresourceforcompanieswishingtoestimateemissionsoftheseGHGs.Thewordingwasmodifiedtohelpclarifythedifferencebetweenorganizationalboundariesandoperationalboundaries.Section4ThediscussionondeterminingobjectivesofaGHGinventorywasabbreviated.G-2Version1.1July8,2005ThesectiononidentifyingboundaryconditionsoftheinventorywasrevisedtoreflectchangesintheMarch2004GHGProtocol(WRI2004a).ThereaderisreferredtotheGHGProtocolforadditionalinformationondeterminingorganizationalboundaries.Subsection4.3.2wasexpandedtoprovidemoreinformationonthedifferencesbetweenfuelenergyintermsofGCV(HHV)andNCV(LHV),includinganestimateoftherelationshipbetweenGCVandNCVforbiomassfuels.Theterm“climateneutral”nolongerappearsinthereportbecauseitisinaccurate;i.e.,methaneandnitrousoxideemissionsfrombiomasscombustionmustbeincludedinGHGinventorytotals.Ashortsectiononbiomassfuelswasaddedexplainingwhybiomass-derivedCO2emissionsareoftencalled“carbonneutral.”Throughouttherestofthereport,however,theterms“biomass,”“biomassfuels,”or“biomasscarbon”areusedinsteadof“carbonneutral.”Sections5and6Thesesectionsareinthereverseorderoftheoriginalreportandthediscussionhasbeenmodifiedextensivelytohelpclarifyorganizationalandoperationalboundaryissues.Section7ThediscussionofmaterialityandinsignificantemissionswasrevisedtoreflecttheguidanceintheMarch2004GHGProtocol(WRI2004a).Section8Adiscussionofdifferingpurposesofinventoriesthatcaninfluencetherequiredlevelofresolutionofemissionestimateswasincluded,aswellasdiscussionofsource-specificversusfacility-specificactivitydataindevelopinganinventory.Adiscussionofvariabilityofemissionfactorsforcoalandfordifferinggradesofnaturalgaswasadded.Thediscussiononcorrectionstoemissionfactorstoaccountforunoxidizedcarbonwasexpanded.AtableofIPCCrecommendedcorrections(Table3)wasadded.Adiscussionofmethaneemissionsfromsomenaturalgas-firedcombustiondevicesthatmaybehigherthanthoseindicatedbypublishedemissionfactorswasadded,includinghowsourceemissiontestingresultscanbeusedtoestimateemissionsfromthesesources.AdiscussionoftheappropriateuseofTier1versusTier2emissionfactorsforestimatingmethaneandnitrousoxideemissionswasadded,aswellasatableoftheIPCCTier1emissionfactorsformethaneandnitrousoxide(Table4).Thediscussiononestimatingmethaneandnitrousoxideemissionsfromcombinationfuelfiredboilersburningbiomassandfossilfuelswasrevisedandexpanded.Version1.1G-3July8,2005Asummaryofguidanceforestimatingmethaneandnitrousoxideemissionsfromstationarycombustionsourceswasadded.Theexamplecalculationforestimatingemissionsfromnaturalgasconsumptionwasrevisedtoclearlyindicatethatthecalculationisbasedonfacility-specificactivity(fuelconsumption)datacombinedwithTier1emissionfactorsformethaneandnitrousoxide.Theexamplecalculation“CO2,CH4,andN2Oemissionsfromnaturalgasuseatasmallmill”wasmodifiedbychangingthenaturalgasdensityparameterfrom0.8kg/m3to0.673kg/m3.Anmatherrorwasalsocorrectedinthisexamplecalculation.Section9ThefootnotesforTable6(emissionfactorsforkraftmilllimekilnsandcalciners)wererevised.Section10InformationonCO2emissionsfrommake-upcarbonateconsumptionwasassignedasubsectionnumber(10.1)Anewsubsection(10.2)wasaddedwhichdiscussesCO2emissionsfromlimestoneanddolomiteconsumptioninfluegasdesulfurization(FGD)systems.Slightwordingchangeshavebeenmadeinthissectionandelsewhereinthereporttoclarifythatonlyimportedelectricity,steam,orheated/chilledwaterthatis“consumed”bythecompanymustbeincludedincalculationsofindirectemissions.Iftheimportedenergyismerelytransmittedtoanothercompany,ithasnotbeen“consumed”andisnotassociatedwithindirectemissions.Section11ThediscussiononreportingbiomasscombustionCO2emissionswasrevisedtoreflectthattheMarch2004GHGProtocol(WRI2004a)nolongerreferstothereportingoftheseemissionsas“supportinginformation.”Adiscussiononemissionsfromthecombustionofnon-condensablegases(NCGs)fromthekraftpulpingprocesswasincluded.AdiscussionaboutwhyitmaybemostappropriatetousetheIPCCTier1emissionfactorsforwood-firedcombustionequipmentotherthanboilers,ratherthanthosedevelopedforindustrialboilers,wasadded.Thediscussiononestimatingemissionsfromcombinationfuel-firedboilersburningbiomassandfossilfuelswasrevisedandexpanded.G-4Version1.1July8,2005Section12Thediscussiononaccountingfortransmissionanddistributionlossesassociatedwithimported/purchasedelectricitywasexpandedtoreflectguidanceintheMarch2004GHGProtocol(WRI2004a).Thesubsectionthatdiscussednettingimportsandexportsofelectricity/steamwasdeleted(thestatement“[c]ompanieswantingtoconformtotheWRI/WBCSDGHGProtocolshouldnotnetimportsandexportsorassociatedemissions”isstillincluded).AnerrorintheexamplecalculationforallocatingemissionsfromCHPsystemsusingthesimplifiedefficiencymethodwascorrected(errorwastypographicalinnature).Wordingwasaddedclarifyingthatemissionsassociatedwithexportedpower,steam,orheated/cooledwaterareasubsetofcompanydirectemissionsandmustbeincludedindirectemissionstotals.Section13Thesubsectionprovidingguidanceonestimatingon-roadtransportationemissionsbasedondistancetraveled(ratherthanbasedonfuelconsumption)wasdeleted.Thetableofdistance-basedemissionfactorswasalsodeleted(thisinformationremainsavailableinAnnexC).AdiscussionofthevarietyofparameterswhichcanaffectCH4andN2Oemissionsfromtransportationvehicleswasadded.Adiscussionofthelessaccurateemissionestimatesresultingfromdistance-basedactivitydataasopposedtoestimatesfromfuelconsumption-baseddata(andassociatedemissionfactors)wasadded.Section14Adiscussiononestimatingmethaneemissionsfromunmanagedpilesofwoodresidualswasadded.Guidancethatcompaniesshouldadjusttheamountsofmateriallandfilledtoaccountforinertwastes(e.g.,boilerash,concrete,etc.),iftherequireddataareavailable,whenestimatingmethaneemissionsfromlandfillswasadded.Section15TextwasaddedexplainingthatCO2resultingfrombiomass-derivedmethanecombustionisnotincludedinGHGinventorytotalsbut,undertheGHGProtocol,itmustbeincludedasadditionalinformation.ItisalsonotedthatCO2generatedbyaerobicwastewatertreatmentsystemsisgenerallynotreportedatallbecauseitisnotcombustionrelated.Version1.1G-5July8,2005Section16Theexampletableforreportingdirectemissions(Table12)wasrevisedtoincludeaplacetoreportadditionalinformationassociatedwiththeportionofdirectemissionsthatareattributabletoexportsofenergy(theseareasubsetoftotaldirectemissions,andarenottobesubtractedfromtotaldirectemissionsintheexamplereportingformat).Inaddition,“0.0”wasreplacedby“N/A”inthecellsforreportingCO2emissionsfrombiomasscombustion,landfillemissions,andanaerobicwastewatertreatmentplantemissions.CorrespondingrevisionsweremadetoTable16.Theexampletableforreportingindirectemissions(Table13)wasrevisedtodeletetheoptionofreportingdirectemissionsassociatedwithexportsofenergy.CorrespondingrevisionsweremadetoTable17.Intheexampletableforreportingemissionfactors(Table14),“0.0”wasreplacedby“N/A”inthecellsforreportingCO2emissionfactorsforbiomassfuelcombustion.CorrespondingrevisionsweremadetoTable18.ReferenceSectionThereferencesectionwasupdatedtodeleteliteraturecitationswhichwerenolongercitedinthebodyofthereport.Allinternetaddresseswereupdatedwherenecessary.Newcitationswereaddedwherenecessary.AnnexesAnnexA(GHGemissionsfromstationaryfossilfuelcombustion–overviewofmethodsinexistingprotocols)wasremoved.AnnexC(CH4andN2Oemissionsfrombiomasscombustion–overviewofmethodsinexistingprotocols)wasremoved.AnnexD(GHGemissionsattributabletoimportsandexportsofpowerandsteam–overviewofmethodsinexistingprotocols)wasremoved.AnnexH(AllocatingGHGemissionsfrompartlyownedorpartlycontrolledsources–overviewofmethodsinexistingprotocols)wasremoved.Anewannexcontainingreproductionsofthetablesofemissionfactorscontainedinthebodyofthereportwasadded.Anewannexpresentingasummaryofsignificantrevisionstoversion1.0ofthetoolwasadded.Allremainingannexeswereupdatedtoreflectthecurrentguidancefromvariousnationalandinternationalprotocols.G-6Version1.1July8,2005ThebiomasscombustionCO2emissionfactorsforspentpulpingliquors,presentedinAnnexE(TableE3),werecorrectedtoeliminateanapproximate5%error(errorwasintroducedwhenincorrectlyconvertingmassofcarbontocorrespondingmassofcarbondioxide).ThefootnotetoTableE3wasmodified.ThiscorrectionnecessitatedmodifyingtheexamplecalculationinTableE2.Version1.1H-1July8,2005ANNEXHREFERENCESFORANNEXESATHROUGHGAustralianGreenhouseOffice(AGO).2004.FactorsandMethodsWorkbook,August2004.AustralianGreenhouseOffice,Canberra,Australia.http://www.greenhouse.gov.au/challenge/tools/index.html(27October2004).AEATechnology.2001.UKgreenhousegasinventory1990-1999:AnnualreportforsubmissionundertheFrameworkConventiononClimateChange.Oxfordshire,England:NationalEnvironmentalTechnologyCentre.http://www.aeat.co.uk/netcen/airqual/reports/ghg/ghg2.html(29October2004)EnvironmentCanada.2004.Canada’sgreenhousegasinventory1990-2002.Ottawa:EnvironmentCanada.http://www.ec.gc.ca/pdb/ghg/inventories_e.cfm(28October2004).EuropeanEnvironmentAgency(EEA).2004.EMEP/CORINAIREmissioninventoryguidebook-Thirdedition,September2004Update.Copenhagen:EuropeanEnvironmentAgency.http://reports.eea.eu.int/EMEPCORINAIR4/en(27October2004).FinlandMinistryoftheEnvironment.2004.GreenhousegasemissionsinFinland1990–2002,NationalInventoryReport.Helsinki:FinlandMinistryoftheEnvironment.http://www.ymparisto.fi/download.asp?contentid=11372&lan=en(28October2004).FortumPowerandHeatOy(Fortum).2001.MethaneandnitrousoxideemissionsintheFinnishenergyproduction.Fortum,Finland:FortumPowerandHeatOy.Georgia-PacificCorporation(GP).2002.ProtocolfortheinventoryofgreenhousegasesinGeorgia-PacificCorporation.Atlanta,GA:Georgia-PacificCorporation.http://www.gp.com/enviro/strategy/protocol.pdf(30October2004).Hough,G.1985.Chemicalrecoveryinthealkalinepulpingprocesses.Atlanta,GA:TAPPIPress.IntergovernmentalPanelonClimateChange(IPCC).1997a.Revised1996IPCCguidelinesfornationalgreenhousegasinventories:Reportinginstructions(Vol.1).IPCCNationalGreenhouseGasInventoryProgram.http://www.ipcc-nggip.iges.or.jp/public/gl/invs4.htm(30October2004).IntergovernmentalPanelonClimateChange(IPCC).1997b.Revised1996IPCCguidelinesfornationalgreenhousegasinventories:Workbook(Vol.2).IPCCNationalGreenhouseGasInventoryProgram.http://www.ipcc-nggip.iges.or.jp/public/gl/invs5.htm(30October2004).IntergovernmentalPanelonClimateChange(IPCC).1997c.Revised1996IPCCguidelinesfornationalgreenhousegasinventories:Referencemanual(Vol.3).IPCCNationalH-2Version1.1July8,2005GreenhouseGasInventoryProgram.http://www.ipcc-nggip.iges.or.jp/public/gl/invs6.htm(30October2004).IntergovernmentalPanelonClimateChange(IPCC).2000.Goodpracticeguidanceanduncertaintymanagementinnationalgreenhousegasinventories.IPCCNationalGreenhouseGasInventoryProgram.http://www.ipcc-nggip.iges.or.jp/public/gp/english/(30October2004).JapanPaperAssociation(JPA).2001.VariouspersonalcommunicationsbetweenMasaoTaniguchiofJPAandReidMinerofNCASI.Tokyo:JapanPaperAssociation.JapanPaperAssociation(JPA).2002.VariouspersonalcommunicationsbetweenJPAandReidMinerofNCASI.Tokyo:JapanPaperAssociation.Miner,R.,andUpton,B.2002.Methodsforestimatinggreenhousegasemissionsfromlimekilnsatkraftpulpmills.Energy27(8):729-738.NationalCouncilforAirandStreamImprovement,Inc.(NCASI).1980.Astudyofwood-residuefiredpowerboilertotalgaseousnon-methaneorganicemissionsinthePacificNorthwest.AirQualityTechnicalBulletinNo.109.ResearchTrianglePark,NC:NationalCouncilforAirandStreamImprovement,Inc.NationalCouncilforAirandStreamImprovement,Inc.(NCASI).1985.VolatileorganiccarbonemissionsfromwoodresiduefiredpowerboilersintheSoutheast.TechnicalBulletinNo.455.ResearchTrianglePark,NC:NationalCouncilforAirandStreamImprovement,Inc.NationalCouncilforAirandStreamImprovement,Inc.(NCASI).1999.EvaluationoftheEPA-recommendedapproachtopredictingairemissionsfrompulpandpaperlandfills.TechnicalBulletinNo.790.ResearchTrianglePark,NC:NationalCouncilforAirandStreamImprovement,Inc.SwedishEnvironmentalProtectionAgency(SwedishEPA).2004.Sweden’snationalinventoryreport2004–SubmittedundertheUnitedNationalConventiononClimateChange.Stockholm:SwedishEnvironmentalProtectionAgency.http://www.internat.naturvardsverket.se/documents/pollutants/climate/climate/fcccdata/NIR.pdf(27October2004).TechnicalResearchCenterofFinland.2001.GreenhousegasemissionsandremovalsinFinland.Espoo:TechnicalResearchCenterofFinland.http://www.vtt.fi/inf/pdf/tiedotteet/2001/T2094.pdf(28October2004).UnitedStatesDepartmentofEnergy(USDOE).1994.VoluntaryReportingofGreenhouseGasesProgram–GeneralguidelinesandsupportingdocumentsestablishingtheVoluntaryReportingofGreenhouseGasesProgram,AppendixB,TableB1.Washington,DC:UnitedStatesDepartmentofEnergy.http://www.eia.doe.gov/pub/oiaf/1605/cdrom/pdf/gg-app-tables.pdf(30October2004)Version1.1H-3July8,2005UnitedStatesEnvironmentalProtectionAgency(USEPA).1993.AnthropogenicmethaneemissionsintheUnitedStates:Estimatesfor1990,ReporttoCongress.EPA430-R-93-003.Washington,DC:UnitedStatesEnvironmentalProtectionAgency.UnitedStatesEnvironmentalProtectionAgency(USEPA).1996.AP-42emissionfactorsforanthracitecoalcombustion–SupplementB,October1996.Washington,DC:UnitedStatesEnvironmentalProtectionAgency.http://www.epa.gov/ttn/chief/ap42/ch01/final/c01s02.pdf(30October2004).UnitedStatesEnvironmentalProtectionAgency(USEPA).1998a.AP-42emissionf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