评估中国水泥行业的净零排放路径（英文版）

BuildingTechnologies&UrbanSystemsDivisionEnergyTechnologiesArea

LawrenceBerkeleyNationalLaboratory

EvaluatingNet-ZeroEmissionPathwaysforChina’sCementIndustry

HongyouLu1,NanZhou1,HonLeungCurtisWong1,XianZhang2

1LawrenceBerkeleyNationalLaboratory,2TheAdministrativeCenterforChina’sAgenda21

EnergyTechnologiesAreaJune6,2024

/10.20357/B75W27

ThisworkwassupportedbytheAssistantSecretaryforEnergyEfficiencyandRenewableEnergy,

BuildingTechnologiesOffice,oftheUSDepartmentofEnergy

underContractNo.DE-AC02-05CH11231.

Disclaimer:

ThisdocumentwaspreparedasanaccountofworksponsoredbytheUnitedStatesGovernment.Whilethisdocumentisbelievedtocontaincorrectinformation,neithertheUnitedStatesGovernmentnoranyagencythereof,northeRegentsoftheUniversityofCalifornia,noranyoftheiremployees,makesanywarranty,expressorimplied,orassumesanylegalresponsibilityfortheaccuracy,completeness,orusefulnessofanyinformation,apparatus,product,orprocessdisclosed,orrepresentsthatitsusewouldnotinfringeprivatelyownedrights.Referencehereintoanyspecificcommercialproduct,process,orservicebyitstradename,trademark,manufacturer,orotherwise,doesnotnecessarilyconstituteorimplyitsendorsement,recommendation,orfavoringbytheUnitedStatesGovernmentoranyagencythereof,ortheRegentsoftheUniversityofCalifornia.TheviewsandopinionsofauthorsexpressedhereindonotnecessarilystateorreflectthoseoftheUnitedStatesGovernmentoranyagencythereofortheRegentsoftheUniversityofCalifornia.

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No.9-037-24+HongyouLu

EvaluatingNet-ZeroEmissionPathwaysfor

China’sCementIndustry

HongyouLu

LawrenceBerkeleyNationalLaboratory

1CyclotronRoadMailstop90R2121,Berkeley,CA94720

Email:

hylu@

HonLeungCurtisWong

LawrenceBerkeleyNationalLaboratory

1CyclotronRoadMailstop90R2121,Berkeley,CA94720

Email:

curtis_wong@

NanZhou

LawrenceBerkeleyNationalLaboratory

1CyclotronRoadMailstop90R2121,Berkeley,CA94720

Email:

NZhou@

XianZhang

TheAdministrativeCenterforChina’sAgenda218YuyuantanSouthRoad,HaidianDistrict,Beijing,China

Email:

zhangxian@

Abstract

China’scementindustryemitsover1Gtofcarbondioxide(CO2)annually,or3%ofglobalCO2emissions.

UrgentdecarbonizationeffortsoftheChinesecementindustryareneededtomeetChinaandglobalcommunity’sclimatecommitments.Priorstudiesonthistopicprimarilyreliedonsupply-sidetechnologiesandend-of-pipe

solutions,presentingonesingularpathwaytonetzerowithoutexploringmultipletrajectories.

Thisstudyaddsvaluetotheexistingresearchbyconstructingandevaluatingtwodifferentpathwaystowardnet-zeroemissionsinChina’scementindustry:theEnergyTechnologyPathway(ETP)andtheCircularEconomy

Pathway(CEP).Bothpathwaysaimfornet-zeroemissionsbutdivergeintheirprioritizationandemphasis.TheEnergyTechnologyPathwayfocusedonsupply-sidetechnologiessuchasgreenhydrogenandCCS,whiletheCircularEconomyPathwayfocusedondemand-sidestrategies,centeredonmaterialsandresources.

Thestudyshowedbothpathwayscanachieveacomparablelevelofemissionreduction,reducing94-95%ofCO2emissionsby2060fromthe2020level.Notably,theroleofCCSislimitedintheCEP,contributingonly5%and22%oftotalemissionreductionsby2030and2060,respectively.Themajorityoftheemission

reductionsinCEPareachievedthroughacombinationofmaterial-focusedinnovationsandcirculareconomy

strategies,suchasincreasingtheuseofsupplementalcementitiousmaterials(SCMs),advancingalternative

cements,integratingmaterialefficiencypracticesinproductlifecyclephases,andadoptingalternativefuels(e.g.,industrialwastesandagriculturalbyproducts).Policysupportonmaterialsandthecirculareconomywillbe

critical.Werecommendupdatingcodesandstandardstoallowperformance-basedcementproducts,providingR&Dsupportonalternativecements,developingimplementationguidestodisseminatematerialefficiency

practices,andimprovingmaterial/wastecollection,sorting,andrecyclingsystems.

Introduction

Cementandcementproductsarefoundationalmaterialsforsociety.Theyareusedextensivelyinresidentialandcommercialbuildings,industrialfacilities,highwaysandbridges,andothertransportationsystems,powerplants,andinfrastructuresystemstodistributeelectricity,heat,gas,andwater.Globally,thecementindustryisoneof

themostenergyandcarbon-intensivesectors.Itaccountedfor7%ofglobalcarbondioxide(CO2)emissions(GCCA2021),orabout3.5gigatonnes(Gt)ofCO2emissionsperyear.

Chinahasbeentheworld’slargestcement-producingcountryforatleast20years.In2022alone,itproducedatotalof2.1billiontonnesofcement,accountingfor52%ofglobalproduction(USGS2023).CO2emissions

fromtheChinesecementindustryrepresented13%ofChina’stotalCO2emissionsin2020(XinhuaNet2022).ToachieveChina’sclimategoals,i.e.,carbonpeakingbefore2030andcarbonpeakingbefore2060(or“DualCarbon”goals),itisimperativetosignificantlymitigateChina’scementindustryemissions.

MostofthecurrentresearchondecarbonizingChina’scementindustryfocusedonsupply-sidetechnologiesand/orend-of-pipesolutions,whicharecomplexengineeringsystemsandcapitalintenvise.Priorresearch

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showedthattechnologiessuchasfuelswitchingandcarboncapture,utilization,andstorage(CCUS)willplaysignificantrolesinachievingnear-zeroemissionsinChina(Heetal.2023;RMIandChinaCementAssociation2022;Li2021).Often,previousstudiespresentonlyonepathwayasthemostplausiblepathwaytonet-zero

emissions,withoutexploringmultiplepathwaystodeepmitigation.

ThisanalysisaddsvaluetotheexistingliteratureandstudiesonChina’scementindustrydecarbonization.Wedevelopedthreescenariosandcomparedtwopotentialnear-zeropathways–anEnergyTechnologyPathway(ETP),andaCircularEconomyPathway(CEP).Bothpathwayshavethepotentialtoreducethecement

industry'sCO2emissionstonearzero.However,thepathwaysdifferintheirprioritizationandemphasisondecarbonizationstrategies,withtheETPfocusedonsupply-sidetechnologiessuchasgreenhydrogenandCCUS,andtheCEPfocusedondemand-sideandcirculareconomystrategiessuchasmaterialefficiency

strategies,clinkersubstitution,andalternativecements.

First,weprovidedanoverviewofthecurrentstatusoftheChinesecementindustry.Then,webriefly

summarizedthemodelingapproach,includingthemodelingframework,scenariodesigns,andkey

characteristicsofeachofthescenarios.TheResultsSectionpresentedthemainfindingsofthisanalysis,

highlightingtheenergyandemissionimplicationsandcontributionsfromeachofthedecarbonizationstrategies.

WediscussedthepolicyimplicationsforChinaandotheremergingeconomies.Thepurposeofthispaperistodevelopabottom-updecarbonizationroadmapforChina’scementindustry.Inaddition,someofthepolicy

findingsmaybealsobeneficialforotheremergingeconomies,whichareexpectedtohavehighercementdemandwhilemeetingtheirclimatechangegoals.

CementIndustryinChina

ThecementindustryplaysanimportantroleinsupportingChina’seconomicgrowthandurbanization.WiththedevelopmentofChina’seconomyandurbanization.,China’scementproductionincreasedfrom232million

tonnes(Mt)in1990tomorethan2,100Mtin2022,growing7.2%peryearonaverage.By2022,China’s

cementproductionrepresented52%ofthetotalproductionintheworld.AsshowninFigure1,cement

productioninChinaseemedtohavepeakedin2014andthenbegantograduallydeclineataround2%peryearonaveragefrom2014to2022(NBS2023).China’scementindustryhaspledgedtoachievecarbonpeaking

before2023,aheadofChina’snationalclimategoal(CBMF2022;ChinaGovernmentWebsite2022).MostoftheexpertsweinterviewedagreethatreachingcarbonpeakingisnotachallengeforChina’scementindustry,giventhatbothclinkerandcementproductionseemtohavealreadypeaked,andfurtherdemandreductionis

expected.

Figure1.China’scementproductionintheworld(1990-2022)

Sources:USGS2023;NBS2023.

China’scementproductionandconsumptionarestronglylinkedtoreal-estateindustrydevelopmentandfixed-assetsinvestment.Onaverage,about40%ofcementisusedtodevelopurbanbuildingswhileanother35%isusedforinfrastructuresystems,suchasenergysupplysystems,railways,roads,pavements,andhighways

(Figure2top).Theremaining25%ofcementisusedinruralhousingandinfrastructure.Overtheyearsof

urbanizationandeconomicdevelopment,theconstructiontypeofChineseruralhousinghasbeenshiftingfromtraditionalbrickandmortarwallstopouredconcretewalls.Inaddition,about60%ofthecementproducedin

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Chinaisusedtomakeconcreteproducts.Mortarproductionandbrickproductioneachaccountedforanother20%ofcementconsumption(Figure2bottom).

Figure2.Cementconsumptionbymarketsegments(left)andproduct(right)inChina

Source:personalcommunicationwiththeexpertsfromtheChinaCementAssociation.

ThecementindustryisthesecondlargestCO2-emittingindustryinChina,aftertheironandsteelindustry.By

2020,thecementindustrycontributedto13.5%ofChina’stotalCO2emissions(XinhuaNet2022).Theprocess-relatedCO2emissions,i.e.,calcinationoflimestone,represented60%oftotalemissions.Onsitefuelcombustion

forcementproductionaccountedforabout35%oftotalCO2emissionsinthecementindustry.Emissionsassociatedwithpurchasedelectricity(Scope2emissions)representedabout5%oftotalCO2emissionsinChina’scementindustry(Heetal.2023).

Bytheendof2022,Chinahad1,572rotarykilnproductionlineswithadesignedtotalclinkerproduction

capacityof1.84billiontonnesperyear.Theactualclinkerproductioncapacityisestimatedtobemorethan2

billiontonnesperyear(DigitalCement2023a).Inthepast10to15years,theChinesegovernmentimplementedpoliciessuchas“replacingsmall,inefficientwithlarger,efficientcapacities”(Zhouetal.2022;XinhuaNet

2018).Smallerkilnshavebeenreplacedwithlargerandnewercapacities.By2022,about75%oftheclinker

capacitycamefromkilnswithacapacityof2,500tonnesperday(tpd)orhigher.About69%oftheclinker

capacitywasfromkilnswithacapacityof4,000tpdorhigher(ChinaEnvironmentalImpactAssessment2023).

TheChinesegovernmenthasbeenencouragingindustryconsolidationstophaseoutinefficientcapacitiesand

improveefficiency.By2022,about58%oftheclinkerproductioncapacitybelongtotheTop10largestcementmanufacturersinChina(Table1).AbouthalfoftheTop10cementcompaniesarestate-ownedenterprises

(SOEs),eitheratthecentralorprovinciallevel,andtheseSOEscontrolledalmost50%ofthetotalclinkerproductioncapacityinChina.ItcouldbearguedthattheseSOEshavemoreresponsibilityandpressuretodecarbonizeChina’scementindustryandsupportChina’s“DualCarbon”climategoals.

TopCompanies(2022)Capacity

Table1.10CementinChinabyClinkerProduction

No.

Companies[English]

Companies[Chinese]

2022Clinker

ProductionCapacity

(Mt/year)

Shareof

National

Total

Ownership

1

ChinaNationalBuildingMaterialsGroup

中国建材集团

385

21%

CentralSOE

2

AnhuiConchCement

安徽海螺水泥股份有限公司

221

12%

ProvincialSOE(Anhui)

3

TangshanJidongCement

唐山冀东水泥股份有限公司（含金隅）

109

6%

Provincial

SOE(Beijing)

4

HongshiHoldingsGroup

红狮控股集团有限公司

67

4%

Private

5

ChinaResourcesCement

华润水泥控股有限公司

67

3%

CentralSOE

6

HuaxinCement

华新水泥股份有限公司

63

3%

ForeignwithlocalSOE*

7

ShandongShanshuiCementGroup

山东山水水泥集团有限公司

54

3%

Private

8

TaiwanCement

台湾水泥股份有限公司

43

2%

Foreign

9

TianruiCementGroup

天瑞水泥集团有限公司

34

2%

Private

10

AsiaCement

亚洲水泥（中国）控股公司

22

1%

Foreign

Sources:DigitalCement2023b;Downie2021.

*Foreignwithlocal(HuangshiCity,HubeiProvince)SOEasaminorityshareholder.

CementmanufacturinginChinaisalocalizedproduction.Everyprovince(orprovincial-levelmunicipality)hascementproduction(Figure3).In2022,Guangdongprovinceproducedthemost,at151Mt,or7%ofthenational

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total;whileBeijingproducedtheleast,at2Mt,or0.1%ofthenationaltotal.CementproductionismoreconcentratedinthesoutheastregionofChina,butalsosignificantinthesouthwestandcentralChina.

Thisleveloflocalization,partlybasedontheabundantavailabilityofrawmaterials(e.g.,limestone)andpartlydrivenbytheneedtoreducetransportationcosts,shouldbeconsideredwhenidentifyingpotentialtechnologies(e.g.,greenhydrogenorrenewables)andstrategiestodecarbonizethecementindustry.Torapidlydecarbonizethecementindustry,standardsandregulationsoncement(andcement-basedproducts)needtothinkbeyond

national-level,“onesizefitsall”requirements,butallowcementproductiontobeadaptivetolocalresourcesofrawmaterialsandenergysources,aswellaslocalspecificapplications.

Figure3.CementproductionbyprovinceinChina(2022)

Sources:NBS2023;thisanalysis.

Duringthe14thFive-YearPlan(2021-2025),theChinesegovernmentalsoestablishedtargetstoimprovethecementindustry'senergyefficiency,increasetheuseofalternativefuels,andlimitclinkerproductioncapacity.Thisincludesanenergyintensityreductionof3.7%by2025fromthe2020levelforclinkerproduction,

increasingtheshareofproductioncapacitytoreachenergy-efficiencybenchmarklevelsto30%by2025,

increasingthepercentageofkilnsthatusealternativefuelstomorethan30%,andlimitclinkercapacitytobenomorethan1.8billiontonnesby2025(Table2).

Table2.EnergyandcarbontargetsforthecementindustryinChina

Categories

Indicators

Targets

CO2mitigation

Carbonpeaking

Before2023

Energyefficiencyimprovement

Energyintensityofclinkerproduction

Reducing3.7%by2025from

2020level

Shareofproductioncapacityreachingtheannounced

benchmarklevelinenergyefficiency(seeTable3below)

30%by2025

Alternativefuels

Shareofkilnsusingalternativefuels

>30%by2025

Limitproductioncapacity

Clinkercapacity

Nomorethan1.8billiontonnesby2025

Source:CBMF2022;LBNLanalysis.

Specifically,theChinesegovernmentrecentlyre-focusedonimprovingindustrialenergyefficiencyand

indicatedthatitplannedtoleveragetheactionsofindustrialenergyefficiencytoadvanceeffortsoncarbonmitigation.TheNationalDevelopmentandReformCommittee(NDRC)ofChinaannouncedguidanceon

Promotingenergyconservationandemissionreductioninkeysectorsbystrictlyusingenergyefficiency

requirementsin2021(NDRC2021a).NDRCpublishedEnergyEfficiencyBenchmarkandStandardLevelsfor

KeyIndustrialSectors(2023version)inJune2023(NDRC2023).Thecementindustryisrequiredtohave30%oftheclinkerproductioncapacityreachtheenergyintensityof100kilogramsofcoalequivalent(kgce)pertonneofclinkerby2025(Table3).

Table3.EnergyintensitybenchmarkandstandardlevelsforclinkerproductioninChina

Keyindustry

BenchmarkLevels

StandardLevels

ReferenceStandard

5

Clinkerproduction

100kgce/tclinker2.93GJ/tclinker

117kgce/tclinker3.42GJ/tclinker

GB16780

Source:NDRC2023.

Toachievethetarget,NDRCrequireslocalgovernmentstodevelopatimelineandannualplanstoeitherretrofitorphaseoutinefficientcapacities.TheChinesegovernmentalsoencouragesthelocalgovernmentstouse

existingpolicytools,suchasloans,greencredits,greenbonds,climatefinance,differentialpricing,supervisionandinspection,andenforcementofenvironmentalprotectionlaws.

However,specificpoliciesonhowtoacceleratethecementindustrytoachievenet-zeroemissionsby2060seemlackinginChina.ChineseexpertsthatweinterviewedforthisstudyexpectthecementindustrytobeincludedinChina’scap-and-tradeprogramsoon.Discussionsonlow-carboncementaswellastheuseofcarboncapture,

utilization,andstorage(CCUS)arealsoongoing.However,urgentpolicyactionsareneededtoexpandbeyondimprovingenergyefficiencyandtacklethedecarbonizationchallengeusingaportfolioofstrategiesfromboththesupply-sideanddemand-sidesolutions.Thus,weconductedthisstudy,developedmultiplepathways

buildingonChina’sexistingtargetsandpolicyguidance,andcomparedtheirdifferencesinreachingnear-zeroby2060.Weespeciallyhighlightedthematerial-level,demand-sidestrategiesthathavenotbeenemphasizedbyexistingpolicies.

ModelingApproach

ModelingFramework

ThisstudyisdevelopedbasedonthemodelingworkoftheChinaEnergyOutlook2022(Zhouetal.2022),

whichusedBerkeleyLab’sChina2050DemandResourcesEnergyAnalysisModel(China2050DREAM)to

developbottom-upscenarioprojectionsofChina’sfutureenergyandemissions.TheChina2050DREAM

followsabottom-upenergyend-useaccountingframeworkofChina’senergyandeconomicstructurebuiltusingStockholmEnvironmentInstitute’sLowEmissionsAnalysisPlatform(LEAP).UsingtheLEAPplatform,the

China2050DREAMframeworkemploysbothmacroeconomicandnon-linear,physicaldriverstomodel

integratedfeedbackwithinandacrossbuildings,industry,transportation,andenergytransformation(primaryenergysupplyincludingelectricity)sectors.

China2050DREAMdiffersfrommostotherintegratedassessmentmodelsinthatusesnon-linear,physicaldriverssuchaspopulation,demographics,andlandareatodrivethefuturegrowthofenergy-consuming

activitiesinbuildings,industry,andtransport.Innotrelyingsolelyoneconomicgrowthtodrivefutureenergy

consumption,theuseoftheseadditionalphysicaldrivershelpscapturepotentialsaturationeffectsinenergy

equipmentownershipandusage,livingspaceandurbaninfrastructure,andfertilizerusethatcancontributeto

theplateauingofenergydemand.Thisuniqueapproachalsocapturesimportantcross-sectorallinkagesthatmaynotbeinothermodels,suchashowslowdownsinnewbuildingandinfrastructureconstructioncanreduce

domesticcement,steel,andglassdemandforconstruction.Lastly,theChina2050DREAMincorporatesdecades

ofdetailedChineseenergy-relatedstatisticsatsectoralandfuel-specificlevelstracingbackto1980andalsocharacterizesthelatestenergy-consumingtechnologiesintermsofenergyefficiencyandfuelmixforvariousend-uses.

Forcalculatingandreportingprimaryenergyconsumption,theChina2050DREAMusesthedirectequivalentapproach(consistentwiththeIntergovernmentalPanelonClimateChange,IPCC)asthedefaultforconvertingprimaryelectricity,ratherthanthepowerplantcoalconsumption(PPCC)methodusedinChinesestatistics

(Lewisetal.2015).Forcalculatingenergy-relatedcarbondioxide(CO2)emissions,China-specificfuelenergyandheatcontentareenteredintothemodelandmultipliedbytheIPCCdefaultCO2emissionsfactorsfor

specificfossilfuels(IPCC2006).ForotherstudiesdevelopedusingChina2050DREAM,pleaseseeLuetal.

2022andKhannaetal.2019.

ScenarioDesign

ToanalyzethedecarbonizationpathwaysinChina’scementindustry,weconstructedthreescenariosandtwoofwhichhavethepotentialtoreachnear-zeroby2060:

•ReferenceScenario:assumesthatChina’scementproductionwillslowdownsignificantlydrivenby

slowingurbanization,decliningpopulation,andaslowerpaceofeconomicdevelopment(Heetal.2023).Itassumesnoadditionalnewpolicies,withgradualimprovementsinenergyefficiencyimprovementsandslowprogressinenergytransition.

•EnergyTechnologyPathway(ETP):aimstoachievenearnet-zeroemissionsinChina’scementindustryby2060.Itconsidersallpillarsofdecarbonizationfrombothsupplyanddemand-sidestrategies.

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However,thisscenarioemphasizessupply-sidetechnologyinnovation,suchasgreenhydrogen,renewableheating,andcarboncapture,utilization,andstorage(CCUS).Itassumesmajortechnologybreakthroughsandaggressiveadoptionofthesetechnologies,supportedbysignificantinvestmentandpolicysupport.

•CircularEconomyPathway(CEP):aimstoachievenearnet-zeroemissionsinChina’scementindustryby2060.Itconsidersallpillarsofdecarbonizationfrombothsupplyanddemand-sidestrategies.Butthisscenarioemphasizesdemand-sidedeepmitigationmeasures,suchasoptimizingcementconsumption

throughouttheproductvaluechain,improvingbuildingdesign,increasingtheuseofprefabrication,

extendingbuildinglifetime,increasingmaterialsubstitution,andimprovingrecycling,aswellascirculareconomystrategies,suchastheuseofalternativefuelsandlow-carboncements.Itassumesmajorshiftsinbusinessandengineeringpractices,withsignificantregulatoryandpolicysupport.

Table4belowsummarizesthekeydecarbonizationstrategiesandtheemphasisofthemeasuresineachofthethreescenarios.Theboldedareasindicatethesestrategiesareprioritizedintherespectivescenarios.

Table4.Decarbonizationstrategiesofthecementindustryandprioritizationbyscenario

MaterialEfficiency

EnergyEfficiency

ClinkerSubstitution

andAlternative

Cements

FuelSwitching

CCUS

Improvedbuildingdesign;optimizingcementcontentin

concrete

Improvingthermalenergy

efficiency

UseofSCM:coalflyash,blastfurnace

slags

Alternativefuels:industrialwastes,municipalsolid

wastes,agriculturalbyproducts

Post-

combustionCO2capturingtechnologies

Extendingproduct

lifetime;increaseduseofprecastcomponentsandpost-tensioningoffloorslabs

Improvingelectricalenergy

efficiency

UseofSCM:calcinedclay,end-of-life

binder

Onsiterenewables

Oxyfuel

combustionCO2capturingorcalcium

looping

Alternativematerials(e.g.,masstimber);additive

manufacturing

Smartenergymanagement

UseofSCM:otherbyproducts(e.g.,

silicafume,bauxiteresidue,agriculturalbyproductashes)

Hydrogenblending

Integrated

calcium

loopingwiththecalcination

process

Recycling

constructionwastes;

recyclingconcrete

intorecycledconcrete

aggregates

Integrative

design/systemoptimization

Alternativecementchemistry

Concentratedsolar

CO2

mineralization(CO2mixing

andcuring)*

ReferenceScenario

Noadoption

Gradual

improvement

Theclinker-to-

cementratiostaysatthe2020level

Slowreplacementofcoalusing

alternativefuels

Noadoption

Energy

TechnologyPathway

Moderateadoption

Approachingpractical

minimumlevels

Moderatelyusing

clinkersubstitutionsandalternative

cements

Aggressive

implementationofzero-carbonsources(greenH2and

renewableheating)

Aggressivelarge-scaleadoption

CircularEconomyPathway

Aggressiveadoption

Approachingpractical

minimumlevels

Aggressively

reducingthe

clinker-to-cement

ratioandincreasingthedevelopmentanduseofalternative

cements

Aggressivelyusinglow-carbon

alternativefuels**

Limitedadoption

Source:thisanalysis.*CO2mineralizationpotentialismodeledatahighlevelinthispaper.Technologiesaregroupedandcalledas“recarbonation”inthepaper.**Alternativefuelsincludeindustrialwastes,solidwastes,byproducts,agriculturalresidues,and

municipalsolidwastes.Notes:1)SCMstandsforsupplementalcementitiousmaterials.2)Boldedareasareprioritizedwithhighadoption.

Results

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Improvematerialefficiency

OurmodelingresultsshowthatChina’scementproductionwillsignificantlydecline,mainlydrivenbya

decliningpopulation,slowingurbanizationgrowth,andthestructuralshiftoftheChineseeconomicgrowth

modelfrominvestment(e.g.,intherealestateindustryandinfrastructure)todomesticconsumption.Inthe

ReferenceScenario,totalcementproductiondeclinesfrom2,130Mtin2022to1,608Mtby2030,andfurtherto747Mtby2060.

ThetrendofproductiondeclinedeepensintheCircularEconomyPathway(CEP),wheretotalcementproductionis8%and24%lowerby2030and2060,respectively,comparedtoReference(Figure4).Thisadditionaldemandreductionistheresultoftheaggressiveimplementationofstrategiesthatimprovematerialefficiencyofcementandcement-basedproducts.Forexample,CEPexpectsthattheaveragebuildinglifetimeinChinawillbemore

thandoubled(from30yearsto70yearsby2060)in24%ofthenewbuildingsby2030and80%ofallnew

buildingsby2060(Caoetal.2019;Q.Wang2010;AktasandBilec2012;Sandbergetal.2016).Prefabricationtechniqueswillbewidelyadopted,reaching80%

by2060inallurbanresidentialandcommercialbuildings.Inaddition,optimizingtheamountofcementusedinproductstodeliverthe

performanceneededwhileminimizing

consumption,reducingconstructionwastes,and

recyclingofconcreteproductsarealsoaggressivelyadoptedinthisscenario.

Incontrast,theEnergyTechnologyPathway

(ETP)onlymoderatelyimplementedstrategiesthatcanreducematerialdemand,e.g.,the

doublingofaveragebuildinglifetimeonlyaffects

30%ofthenewbuildingsby2060and

prefabricationonlyreached50%oftheurbanbuildings.Thisresultedina4%and9%

Figure4.CementproductioninChinabyscenario(2020-2060)

reductionoftotalcementproductionby2030and2060,respectivelycomparedtotheReference

Scenario.

UseofSCMandalternativecement

Oneofthecost-effectivewaystoreduceemissionsfromthecementindustryistoblendclinkerwith

supplementalcementitiousmaterials(SCMs),whichnotonlyreducesCO2emissionsfromthermalenergy

productionbutalsoprocess-relatedemissions.China’scementindustryhasbeenusingSCMs,suchasflyashfromcoal-firedpowerplantsandgranulatedblastfurnaceslagsfromtheiron-productionprocess.By2020,

China’sclinker-to-cementratiowas0.66andstayedatthislevelthrough2022.Thisisanincreasefromthe

historicallowof0.56in2013,whereverylow-qualitycementwasallowedandproducedatasignificantscale.Toachievenear-zeroemissionsby2060,ourmodelingshowedthatitisessentialfortheChinesecement

industrytocontinueusingSCMs,expandthecategoriesofSCMs(giventhelimitedsupplyofflyashandBFslaginthefuture),andadoptnewSCMtechnologies.Forexample,studiesshowthatsilicafume,bauxit