英文文献325412

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1、CharacterizationofHTSandLTSReactionsinMicrostructuredReactorsMartaPawlak,*MarkusThaler,andViktorHackerInstituteforChemistryandTechnologyofInorganicMaterials,CD-LaboratoryforFuelCellSystems,GrazUniVersityofTechnology,Steyrergasse21,8010Graz,AustriaReceiVedOctober

2、26,2006.ReVisedManuscriptReceiVedMay20,2007TheproductionofhydrogenfromsynthesisgaswithahighCOcontentisinvestigatedwithmicrostructuredreactors.Themainadvantagesofusingmicrostructuredreactorsaretheexcellentheatandmasstransfercharacteristicsinsideofthereactorandthe

3、possibilitytoincludeheatexchangerstoreducethesystemsizeandheatlosses.High-andlow-temperaturewatergasshiftreactionsareexaminedfortheabilitytodecreasetheCOfractionofthesynthesisgasdowntoaleveltolerableforprotonexchangemembranefuelcells.Thesegaspurificationmethodsh

4、avetheadvantageofahigherhydrogenyieldbeingachievableby“converting”COintoH2,thusleadingtoahigheroverallefficiencyofthefuelcellsystem.AnextstepinfurtherreducingtheCOcontentcouldbesifnecessaryspreferentialoxidation.Thehigh-temperatureshiftreactiontakesplaceatatempe

5、ratureofapproximately350°Cinthepresenceofaniron-orchromium-basedcatalyst.Thelowtemperatureshiftreactionisoperatedatapproximately250°Cwithcoppercatalysts.Theperformanceofmicrostructuredreactorsfittedwithdifferentcatalystsisdiscussedwithinthispaperasafunctionofthe

6、temperature,gasflowrate,andgascomposition.IntroductionFuelcelltechnologyhasreachedastageofdevelopmentwhereithasbecomeincreasinglyinterestingforcommercialapplications.Currently,mostofthehydrogenisproducedfromhydrocarbonsbysteamreformingorautothermalreformingcombi

7、nedwithcomplexgas-cleaningprocedures.Atypicalgas-cleaningprocedureincludesthefollowingtwosteps:Thereformedfuelsarefirstpassedthroughthehightemperaturewatergasshift(WGS)stage(HTS)andarethenfedintothelow-temperaturewatergasshiftstage(LTS)toreducetheCOconcentration

8、.Theoutletgasstillcontainssmallamountsofcarbonmonoxide,whichcanpoisontheplatinumcatalystusedinprotonexchangemembranefuelcells.Therefore,preferentialoxidationcanbeutil