ZIF-8吸附剂上CH-4-N-2的吸附分离性能与热力学性质-胡江亮

0253-2409201306-0754-072012-11-142013-01-21。K20110812。[e-mail]。ZIF-8CH4/N2胡江亮1，2，孙天军2，任新宇2，常丽萍1，王树东21．0300242．116023。TEAZnSO4ZIF-8。XＲD、、IGCZIF-8、、。ZIF-8、298KZIF-8CH4/N23．4CH4、N2ZIF-820%。ZIF-8TQ028．1ASeparationofCH4/N2onZIF-8adsorbentanditsthermodynamicpropertiesHUJiang-liang12SUNTian-jun2ＲENXin-yu2CHANGLi-ping1WANGShu-dong21．KeyLaboratoryofCoalScienceandTechnologyTaiyuanUniversityofTechnologyMinistryofEducationandShanxiProvinceTaiyuan030024China2．DalianInstituteofChemicalPhysicsChineseAcademyofSciencesDalian116023ChinaAbstractWithtriethylamineTEAasstructuredirectingagentZnSO4asmetalionsourceandwaterasthesolventzeoliticimidazolateframework-8ZIF-8adsorbentwaspreparedbyhydrothermalsynthesisandusedintheseparationandenrichmentofexhaustedcoal-bedmethane．XＲDphysicaladsorptiondynamicadsorptionequilibriumandinversegaschromatographyIGCmethodswereemployedtocharacterizethephysicalstructurechemicalstabilityadsorptionandseparationperformanceoftheZIF-8adsorbenttheadsorptionthermodynamicsofCH4andN2onitwasalsoconsidered．TheresultsindicatedthatZIF-8structureisstableintheacidalkaliandstronglypolarizedsolvent．At298KtheseparationfactoroftheZIF-8adsorbenttowardsCH4/N2isupto3．4whichiscomparabletoactivatedcarbonhoweverZIF-8shouldbemorepromisinginpracticalapplicationbecausetheadsorptionheatoveritisabout20%lowerthanthatoveractivatedcarbon．Keywordszeoliticimidazolateframework-8adsorptiveseparationmethanenitrogenadsorptionheat、。、、、、。2000m35、1。2%2CH4。CH4CO2203。CH4、、。、CH4/O2、CH4/N2CH4/N2CH4/N2。、、PressureSwingAdsorptionPSA、、CH4。PSACH4/N2CH4/N24。-Metal-OrganicFrameworksMOFs41620136JournalofFuelChemistryandTechnologyVol．41No．6Jun．2013、、。、。ZIFsMOFsMOFs-5。ZIF-86～9、ZIF-8500℃1011。ZIF-8ZIF-8。、ZIF-8。ZIF-8InverseGasChromatographyIGCZIF-8CH4/N2PSACH4/N2。11．12-、、TEA、、。131．4g1．6mol2-2-mIM81g0．8molTEA830mLA57．5g0．2molZnSO4·7H2O250mLB。BA50mL100℃4h。。1．2PANalyticalX＇PertPＲOXCuKα40kV40mA6°/min5°～60°。N2/QuantachromeAutosorb-iQ277K6h。BETDＲ。1．3、1。、、。3mm4mm150mm。AMETEKProLineProcessmassspectrometers60℃、2．7A、5．8V。1Figure1Schematicdiagramofdynamicadsorptionappatatus1CH4/N2mixture2purgegasHe3heatingdevice4adsorbentbedV1～V5two-wayballvalvesV6、V7three-wayballvalvesV8、V9backpressurevalveMFCmassflowcontrollerppressurecontrollerMSmassspectrometerPCcomputerVPvacuumpump5576ZIF-8CH4/N2α=x/yix/yj=n/yin/yj=ni/njyi/yj1xi、xjxi、jyi、yjyi、jni、nji、j。1。ij12。1．4、13。。IGC、、、Gibbs14。IGC。VN15lnVN=lnＲTns-ΔGＲT=lnＲTns-ΔHＲT+ΔSＲ2VN=tＲ-tMqvaTTaj3j=32×pi/po2-1pi/po3-14nstＲmintMminqvamL/minTaKTKjJames-MartinpiPapoPa。VNlnVN1/T△H△S。IGCGC7890TCD、3mm、N2000、99．99%60～80600mm。22．1ZIF-8、。ZIF-8、ZIF-8。16。ZIF-81。ZIF-8XＲD210。1ZIF-8Table1OptimizationofZIF-8synthesisSolventMetal∶ligand∶TEAmolratioMetalsaltTemperaturet/℃Timet/hYieldw/%H2O1∶8∶2ZnSO41004≥90ZIF-8TEATEAZIF-82。2TEAZIF-8TEA2-mIMZIF-817。TEAZIF-865741。ZIF-8-ⅡZIF-81nm1682．018m2/g0．524cm3/g60%。ZIF-8。ZIF-8-ⅡZIF-8。2TEAZIF-8Table2EffectofTEAonporestructureandyieldofZIF-8SampleMetal∶ligand∶TEAmolratioBETsurfaceareaA/m2·g－1DＲmicroporevolumev/cm3·g－1Totalporevolumev/cm3·g－1Porewidthd/nmYieldw/%ZIF-8-Ⅰ1∶8∶0246．1730．0800．1220．82255ZIF-8-Ⅱ1∶8∶21682．0180．5240．8811．076902．2ZIF-8MOFs、MOF。ZIF-83。ZIF-8120℃10hXＲD2。3ZIF-8Table3SolventtreatmentconditionofZIF-8Solvent20%NaOHsolution10%H2SO4solutionMethanolDMFTemperturet/℃10010068153Timet/h242448482ZIF-8XＲDFigure2XＲDpatternsofassynthesizedandaftertreatmentZIF-8248hZIF-8XＲDZIF-8。NaOHH2SO4XＲDZIF-8、。DMFDimethylformamide48hZIF-8011ZIF-8DMF。ZIF-8、。2．3CH4N2ZIF-8CH4N210mL/minHe100mL/min298K。30．9MPaCH4N2ZIF-8CH4N2。i=i+i+i0．2180．737mmol/g1α=3．4。3298K、0．9MPaCH4N2ZIF-8Figure3BreakthroughcurvesoftheCH4/N2mixtureonZIF-8at298Kand0．9MPa4N2CH4。47576ZIF-8CH4/N2。CH425．9×10－25cm3N217．4×10－25cm3ZIF-8。ZIF-8CH4N2。298K18。CH4N2190126K298K、0．5MPaCH4。4CH4/N2ZIF-8Figure4AdsorptionisothermoftheequimolarmixtureofCH4andN2at298K5298KZIF-8CH4/N2。50．1MPa1．90．9MPa3．4。4。ZIF-85。5ZIF-8CH4/N25A、13X。α＞2．0α＞3．0ZIF-8CH4/N2。2．4lnVN1/T26。△Ha、△Sa、△GaＲ4。6CH4N2ZIF-8。5298KCH4/N2ZIF-8、5A、13XFigure5CH4-N2selectivityasafunctionofpressureonZIF-85A13Xandactivatedcarbonat298K6ZIF-8VNFigure6ＲelationbetweennetretentiontimeforCH4/N2andadsorptiontemperatureofZIF-84ZIF-8CH4、N2ＲTable4ThermodynamicparametersofCH4N2onZIF-8andthecorrelationcoefficientＲ－△Ha/kJ·mol－1－△Sa/J·mol－1·K－1－△Ga/kJ·mol－1ＲCH413．98122．6937．1010．9987N210．81920．7284．5350．99924△Ha－14kJ/mol△Hc19。-。ZIF-8、“IM”“IM”CH4。“IM”CH4CH4C=C2085741。4CH4N2ZIF-8CH4N2。CH4N2CH4N2CH4ZIF-8。IGC5A、13X5。5CH4、N25A、13XTable5AdsorptionheatofCH4andN2on5A13XandactivatedcarbonAdsorbentBETsurfaceareaA/m2·g－1－△Ha/kJ·mol－1CH4N25A530．02314．73613．89813X563．17414．57113．572Activatedcarbon1206．43216．97814．0315CH4、N25A、13XZIF-8ZIF-820%ZIF-8。、。3ZIF-8ZIF-8XＲD、ZIF-8。ZIF-8IGCCH4/N2CH4ZIF-8。ZIF-8CH4/N25A13X。1．J．200023z11-5．XIANXue-fu．Thepresentsituationofcoal-bedmethaneminingandutilizationinourcountryandlookingforwardtoitsindustrializationJ．JournalofChongqingUniversityNaturalScienceEdition200023z11-5．2．CH4/N2PSAJ．2011304793-801．YANGJiang-fengZHAOQiangYUQiu-hongDONGJin-xiangLIJin-ping．Progressofrecoveryofcoalbedmethaneanda