碳燃料电池的设计与应用

碳燃料电池的设计与应用团队成员：

SKLCC直接碳燃料电池〔DirectCarbonFuelCell，DCFC〕1.DCFC的研制背景介绍2.DCFC的优势及创新性3.DCFC的反应机理及模型制作4.挑战5.研究计划研制背景“节能减排〞是我国的根本能源政策；火力发电污染物多且效率难有大幅提高；我国是燃煤大国,煤炭是我国的主要能源,研究意义更为显著;

LAMDCoalCombustionElectricalpowerNOxSOXPARTICALSCO270%80%90%67%70%煤燃烧：污染物多DCFC与传统发电方式相比的优势及创新性

SKLCC高效：直接通过电化学反响产生电能，效率可达80%，燃料的理论利用率可达100%清洁：直接、高效地实现C到CO2的转换,有利于CO2的富集与减排，减小污染；固体氧化物作为电解质，便于运输、保存和制造；市场前景广阔〔国内的研究尚在起步阶段，可见潜力巨大，市场广阔，国外研究有一定的成果，也给我们提供了信心。具有广阔的市场应用前景和开发价值，这也符合我们国家倡导的“节能减排〞的政策。〕〔1〕良好的操作性能。〔2〕灵活可靠的输出性能〔3〕灵活的结构特性燃料电池的理论效率∆G/∆H=(∆H-T∆S)/∆H=(1-T∆S/∆H)

LAMD

Generalcharacteristicsofmainfuelcelltypes1

parameterAFC(KOH)PEMFCPAFC(H3PO4)MCFCSOFC(YSZ)Top(℃)<100<100180~200650700~1000FuelH2H2,naturalgas,methanolNaturalgas,methanolNaturalgas,methanol,oil,coalNaturalgas,methanol,oil,coalAnodecatalystNiorPt/CPt/CPt/CNiNiCathodecatalystAgorPt/CPt/CPt/CNiLSMImpuritysensitivityCO2,CO,SS,COSSSEfficiency%45-6040-4540-4545-5545-65CHP(热电联产）

efficiency%>80>80>80>80>80

Generalcharacteristicsofmainfuelcelltypes2

LAMDparameterAFC(KOH)PEMFC(PEM)PAFC(H3PO4)MCFCSOFC(YSZ)Advantages1.start-upfast2.OprateatroomT.P.1.start-upfast2.OprateatroomT.P.flexiblefuelsflexiblefuelsDisadvantages1.Pureoxygen2.Highcost1.VerysensitivetoCO2.humidification

1.start-upslow2.corrosion1.start-upslow2.hightemperature3.corrosion1.start-upslow2.hightemperatureapplicationsDistributedpowergeneration,transport,portablepower,emergencypower,remotecommunication.UniqueattractivefeaturesofDCFC

LAMDGreatthermodynamicadvantagesoverotherfuelcelltypes(H2,CH4)andconventionalpowergenerationplantsat600℃∆S=1.6jK-1mol∆G=-395.4kJmol-1∆H=-394.0kJmol-1Lessemissionsthancoal-firingpowerplantsTen-foldReductioninoffgasvolumeperMWH:–5X—nonitrogenin“fluegas〞–2X—80%efficiencycutsall“fluegas〞inhalfpertonofcoalFuelTheoreticallimit=∆G/∆HUtilizationEfficiencyµV/Vº=εEfficiency=[∆G/∆H][µ][V/Vº]Powerdensity(kW/L)C1.0031.00.800.8020.0CH40.8950.800.800.572.4H20.700.800.800.454.2EvolutionofDCFC1

LAMD

In1896,Dr.WilliamJacquescellsconsistingof100singlecellsAnode:rodsofbakedcoalCathode:ironpotsas,electrolyte:moltenNaOH

400–500◦C100mA/cm−21.5kWThiscouldbeconsideredthefirstDCFC,buttherearemanyspeculationsovertheactualperformanceandtheresultscannotbereproducedbyothers.Thefirstliterature-recorded:Bacquerelle

in1885andJablochkoffin1877builtelectrochemicaldevicesusingelectrode-gradecarbonasanode,Pt/Feascathode,andfusedKNO3aselectrolyte.Suchdevicesproducedelectricalpower,butwereunstableduetoelectrolytedegradation.EvolutionofDCFC2

LAMDTheimprovedefficiencyofthesteam-drivengeneratorattheearlyof20centuryputDCFCtechnologytorestfornearlymorethantwo-thirdofacenturyuntilthe1970s,whenaseriesofstudiesatSRIInternationalverifiedthatitispracticallypossibletocompletelyelectro-oxidizecarbontogenerateelectricity.Inthelastfewyears,studiesontheDCFChaveclarifiedtheearliermisunderstandingoftheDCFC,andhavefirmedtheelectrochemicalfoundationofthedirectconversionofcarbontoelectricity,andhavedemonstratedthefeasibilityofaDCFCatleastonalaboratoryscale.

SKLCCPart3.ResearchstatusaboutDCFCReactionmechanism−notyetfullyunderstood

LAMDVariouselectrochemicalaspectssuchasthenumberofelectronstransferred,roleofreverseBoudouardreactionandpossibleintermediatechemicalreactionsbetweentheanodicspeciesarestillunderinvestigation.ThereactionsequenceproposedbyCherepyisasfollows:2CO32−=2CO2+O22−CRS+O2−=CRSO2−FirstadsorptionCRSO2−=CRSO−+e−FastdischargeCRSO−=CRSO+e−FastdischargeCRSO+O2−=CRSO22−Slowadsorption:RDSCRSO22−=CRSO2−+e−FastdischargeCRSO2−=CO2(g)+e−Fastdischargeandevolution

LAMDPreliminarycostsofstack~$250/kW@2kW/m25−yearlifeofcell(graphitecorrosionat50µm/y)

LAMDFinegrindingyieldsfuelwith<1%S,ash(KentuckylowS,bituminous)•Ashrequireselectrolyteexchange(2−3xperyear)•Totalfuelcost$60/tonSolventextractionyieldscoalwith0.01%ash•Solventloss0.7%/cycle•Charscatalyzedforgasification•Fuelcost~$200/tonCOALSolventextractionFinegrindingBakeFuelcell

SKLCCDirectCarbonFuelCellDCFC使用固体碳作为燃料Solidcarbonisdirectlyintroducedintotheanodecompartmentandelectro-oxidizedtoCO2athightemperaturegeneratingelectricalpower.总反响方程式：C+O2=CO2,E◦=1.02VChallenges

LAMDSinceDCFCtechnologyisstillatthebeginningstage,substantialeffortsneedtobeundertakentoaddresschallenges,bothinthefundamentalandtheengineeringaspects.

Fundamentalthemechanismofelectrochemicaloxidationofcarbon.Theinfluenceofimpurities,likesulfur,chlorineandminerals,onthecarbonelectrooxidationrate,electrolyte,anodecurrentcollectorandotherfuelcellcomponentmaterialsshouldbeexamined.Theresultswilldeterminetowhatextentcarbonfuelshavetobepretreated.

lifetimeanddegradationcorrosionofcellcomponentsathightemperature.Challe