05-水蒸气对分子筛膜的影响

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1、JournalofMembraneScience251(2005)5966EffectsofimpuritiesonCO2/CH4separationsthroughSAPO-34membranesShiguangLi,GuerreroAlvarado,RichardD.Noble,JohnL.Falconer∗DepartmentofChemicalandBiologicalEngineering,UniversityofColorado,Boulder,CO80309-0424,USAReceived2December2003;receivedinrevisedform

2、15October2004;accepted26October2004Availableonline23December2004AbstractTheeffectsofH2O,N2,C2H4,C3H8,andn-C4H10impuritiesonCO2/CH4separationwerestudiedforSAPO-34membranesonstainlesssteelsupports.TheCO2permeancedecreasedby12%,buttheCO2/CH4selectivitywasstableafter12daysofexposureto170ppm.Pe

3、rmeancesandselectivitywerenotsignificantlyaffectedwhen3%N2wasinthefeed.Adding1%hydrocarbons(C2C4)tothefeeddecreasedbothpermeanceandselectivity;C4hydrocarboncausedthelargestdecreasebecauseheavierhydrocarbonshavehigherheatsofadsorptionandthusinhibitCO2permeationmoresignificantly.Higherhydrocar

4、bonconcentrationsdecreasedthepermeanceandselectivitymore.Whenfourimpuritieswereinthefeed,aSAPO-34membraneseparatedCO2fromCH4withselectivityashighas55andaCO2permeanceof4.9×10−8mol/(m2sPa)at297Kandafeedpressureof2.2MPa.Thepercentimpurityinthefeedatlowpressurewasagoodindicationoftheseparation

5、behaviorathigherpressures.HigherimpuritypartialpressuresdidnotresultinmorelossinpermeanceorselectivitywhentheCO2andCH4partialpressureswerecorrespondingincreased.Thepermeancesandselectivitieswerenotpermanentlyreducedbyimpurities,butwererestoredbyremovingtheimpurityfromthefeedorbycalcining.©

6、2004ElsevierB.V.Allrightsreserved.Keywords:Gasseparation;Zeolitemembrane;SAPO-34;Carbondioxide;Methane;Stability1.IntroductionTheirpoorperformancestabilityathightemperatureandhighpressurelimitspolymericmembranesuseforCO2/CH4CarbondioxideseparationfromCH4isimportantinnatu-separation[3].Theh

7、ighpartialpressuresofCO2canplasti-ralgasprocessingbecauseCO2reducestheenergycontentofcizepolymermembranesanddecreasetheirseparationabilitynaturalgas.Also,CO2isacidicandcorrosiveinthepresence[3].Moreover,naturalgascontainsundesirableimpurities,ofwaterwithinthet