solid superacid-catalyzed hydroconversion of demineraliz：固体超强酸催化加氢转化demineraliz1

1/1solidsuperacid-catalyzedhydroconversionofdemineraliz：固体超强酸催化加氢转化demineralizSolidSuperacid-CatalyzedHydroconversionofDemineralizedShengliCoalLiquefactionResidueunderMicrowaveIrradiationYAN-BINWEIaZHI-MINZONGaRUI-LUNXIEaYAO-LIPENGaJIEMOUaYU-MIAOMAaXIAOZHOUaYONGHUANGaLINWUbXIAN-YONGWEIa,b,*aSchoolofChemicalEngineeringChinaUniversityofMiningandTechnologyXuzhou221008,Jiangsu,ChinabKeyLaboratoryofCoalConversionandNewCarbonMaterials,HubeiProvinceWuhanUniversityofScienceandTechnologyWuhan430081,Hubei,ChinaRunninghead:SolidSuperacid-CatalyzedHydroconversionAddresscorrespondencetoXian-YongWei,SchoolofChemicalEngineering,ChinaUniversityofMiningandTechnology,Xuzhou221008,Jiangsu,China.Telephone:+86-516-83885951;Fax:+86-516-83884399;E-mail:wei_xianyong@163.comShenglicoalliquefactionresidue(SLCLR)wasdemineralizedandthedemineralizedSLCLR(DSLCLR)wassubjecttonon-catalyticandSO42-/ZrO2-orSO42-/ZrO2-catalyzedhydroconver-sioninmethanolundermicrowaveirradiation.TheresultsshowthatbothSO42-/ZrO2-andSO42-/ZrO2significantlycatalyzeDSLCLRhydroconversion.Themethanol-extractablesolutions(MEFs)ofhydrogenatedDSLCLRwereanalyzedwithGC/MS.TheMEFsandmethanol-inextractablefractionsofhydrogenatedDSLCLRwerecharacterizedwithFTIR.Keywordssolidsuperacid;coalliquefactionresidue;microwaveirradiationSincecoalliquefactionresidue(CLR)wasproducedinabout30%yieldthroughtheprocesssupportingunitoftheNEDOLcoalliquefactionprocess(Suganoetal.,2002),itsefficientutilizationisimportantforimprovingtheeconomyofcoalliquefactionprocess.ObtainingmoresolublefractionfromCLRanddetailedinformationaboutmolecularcompositionofCLRisessentialfortheefficientutilizationofCLR.CatalystplaysanimportantroleforCLRupgrading.Solidsuperacids(SSAs)areamongthemostimportantandwidelyusedcatalystsinindustrialandlaboratorypractice(Sartorietal.,2004).Shimizuetal.notedthatsuperacidcanenhancethesolubilitiesofligniteandsubbituminouscoalinpyridinewithouthydrogen.TheyfoundsuperacidsuchasHF/BF3canpromotecoaldepolymerizationat150oCanddidnotcausesignificantdealkylation,providingahighersolubilization(Shimizuetal.,1995,1998,1999).Wangetal.(2007)indicatedthattheSO42-/ZrO2exhibitedexcellentcatalyticactivitiesforthepyrolysisandthehydrogenationincoaldirectliquefaction.OtherSSAssuchasSO42-/Fe2O3,SO42-/SnO2andSO42-/Mo/Fe2O3werealsousedinthedirectliquefactionofcoal(Pradhanetal.,1991),butfewreports,ifany,weredrawnattentiontoCLRhydroconversionundermicrowaveirradiation(MWI).Inthepresentstudy,weinvestigatedSSA-catalyzedhydroconversionofDSLCLRinmethanolunderMWI.ExperimentalShenglicoal(aChinesebituminouscoal)liquefactionresidueusedinthisstudywasobtainedthroughaPSUprocessat455oCunder19MPaofhydrogen.Itwasgroundto75manddriedfor24hinavacuumat80oC,thanstoredundernitrogenatmospherebeforeuse.Toavoidtheeffectofmineralmatter,theSLCLRwasdemineralizatedaccordingtotheprocedurereported(Silbernageletal.,1991).TheultimateandproximateanalysesofSLCLRandDSLCLRareshowninTable1.Methanoliscommerciallypurchasedanalytical-purereagentandwasdistilledbeforeuse.Zirconium(ortitanium)hydroxidewaspreparedbyhydrolyzinganaqueoussolutionofazirconium(ortitanium)saltwithaqueousammoniatopH9,thentheprecipitatedsolutionwasstandingovernightatroomtemperature.Finallytheprecipitatewasadequatelywashedwithdistilledwateruntilnochlorideionwasdetectedinthefiltrate,anddriedat120oCfor24h.Afterdrying,thesolidswerepowderedto149mandimpregnatedwithsulfateionsbysuspending4gofdriedhydroxidesin60ml(1mol/L)aqueoussulfuricacidfor2hfollowedbydringat120oCfor24handcalciningat650oCforSO42-/ZrO2,525oCforSO42-/TiO2,respectively.Thephasecompositionsoftheas-preparedcatalystsweredeterminedwithXRD(RigakuD/Max-3BX-raydiffractometerwithCuKradiation)atascanningrateof3o/minin2rangingfrom3oto65o.FTIRspectraofcatalystswererecordedwithNicoletMagnaIR-560system.Hammettindicatorswereusedtomeasuretheacidstrengthofcatalystsprepared.Thehydroconversionswerecarriedoutinan80mLCEMDiscovermicrowavereactor.1.0gDSLCLR,20mLmethanol,0or0.1gacatalystwerechargedintothereactor.Thenitwaspressurizedwithhydrogento0.7MPaatroomtemperature,heatedto140oCwithin3minandkeptatthetemperaturefor15min.Thenitwascooledtoroomtemperature.Thereactionmixturewasfiltratedbyamembranefilterwith0.8mofporesize.TheresiduewasextractedwithmethanolinaSoxhletextractorundertheprotectionofN2forfortnight.ThefiltrateandextractionsolutionwereincorporatedandconcentratedbyevaporatingthesolventusingaBchiR-134rotaryevaporatorfollowedbyGC/MSandFTIRanalyseswithaHewlettPackard6890/5973GC/MSandaNicoletMagnaIR-560FTIR,respectively.Themethanol-inextractablefractions(MIEFs)werecharacterizedwiththeNicoletMagnaIR-560FTIR.Extractyield(EY)inmethanolwasusedtoevaluatethehydroconversionextent.ResultsanddiscussionThecatalystspreparedinthisstudyshowsuperacidity.Theiracidstrengthvaluesare-14.52forSO42-/ZrO2and-13.75forSO42-/TiO2.Thiswasconsistentwiththeresultreported(Gaoetal.,1994).Fig.1showstheXRDpatternsofcatalystsprepared.Clearly,thecrystallinestructureoftheSO42-/TiO2powdergivestheanatasetypein25.2o,andthecrystallinestructureoftheSO42-/ZrO2powderhaspredominantlythetetragonalphasein30.1o.Gaoetal.(1992)notedthatthetetragonalphasehasstrongeraciditythanmonoclinicphaseforSO42-/ZrO2catalyst.Yamaguchi(1990)reportedthattheexistenceofcovalentbondS=Oandmultiplebondsatthesurfaceisessentialstructuralcharacterizationforthesesulfatedoxides(SO42-/MxOy).ItisconsideredthatthegenerationofenhancedacidiccharacteronthesurfaceoftheseSSAsistheresultoftheinductivepullofelectronsfromthecentralmetalatomtowardthebidentatesulfateanion.Tangetal.(1986)reportedthattheinfraredcharacteristicpeakofbidentatesulfateionsexistinginSO42-/MxOyis1200-1280cm-1,1130-1150cm-1and1040-1080cm-1.AsexhibitedinFig.2,theappearanceof1240,1142and1045cm-1absorptionbandforSO42-/ZrO2andthe1224,1138and1043cm-1absorptionbandforSO42-/TiO2revealsthatthesulfatedionsofSSAsarebidentateform.AsFig.3shows,EYincreasedto85.8%overSO42-/TiO2and87.2%overSO42-/ZrO2from62.3%withoutcatalyst,indicatingthatbothSSAssignificantlycatalyzedDSLCLRhydroconversion.AsdemonstratedinFig.4,theabsorbancesofOHat3438cm-1andaliphaticC-Hat2922cm-1,2856and1450cm-1intheMEFsfromhydrotreatedDSLCLRincreasedincomparisonwiththeMIEFs,implyingthatDSLCLRhydroconversionledtothereleaseofOHandaliphaticmoiety-richspeciesfrommacromolecularstructureofDSLCLR.Thechangesintheabsorbanceofaromaticringsat3045cm-1and1604cm-1(Sasakietal.,2000;Basaranetal.,2003;Xie.,2002)comparedtotheMIEFsarealmostnegligibleintheMEFs,suggestingthataromaticstructuresofDSLCLRpossessstabilityduringthehydroconversion.Theincreasesintheabsorbanceofetherat1226cm-1and1060cm-1areappreciableintheMEFscomparedtotheMIEFs.Fig.5displaystotalionchromatograms(TICs)oftheMEFsobtainedunderdifferentconditions.CorrespondingcompoundsidentifiedarelistedinTable2.Intotal,46organiccompoundsweredetectedintheMEFs,includingbenzo[1,2-b:4,5-b’]bis[1]benzothiophene(BBBT,peak44),3normalalkanes(peaks1,3and4),10hydroarenes(peaks11,16,21,22,26,30,33,37,38and45),15substitutedareneswiththreetosixrings(peaks9,10,12,14,15,23-25,27,28,34-36,39and43),8non-substitutedareneswithfourtosevenrings(peaks8,29,31,32,40-42and46)and9oxygen-containingorganicspecies(OCOSs,peaks2,5-7,13and17-20).Benzo[ghi]perylene(peak41)isthemostabundantcompoundidentifiedfromtheMEFsofhydrotreatedDSLCLRwithSO42-/ZrO2andwithoutcatalyst,butforSO42-/TiO2-catalyzedhydroconversion,dibutylphthalate(peak6)isthemostabundantcompound.MuchmoreOCOSsweredetectedinMEFfromSO42-/TiO2-catalyzedhydroconversionthanSO42-/ZrO2-catalyzedandnon-catalytichydroconversions,whilehydroarenesandsubstitutedarenesintheMEFfromDSLCLRhydrotreatedoverSO42-/ZrO2aremoreabundantthanthosewithoutcatalystandoverSO42-/TiO2.ConclusionsBothSO42-/ZrO2-andSO42-/ZrO2significantlycatalyzedDSLCLRhydroconversionpartlybyreleasingOHandaliphaticmoiety-richspeciesfrommacromolecularstructureofDSLCLR.OrganiccompoundsidentifiedintheMEFsincludenormalalkanes,hydroarenes,substitutedarenes,non-substitutedarenes,OCOSsandasulfur-containingorganiccompound.SO42-/TiO2andSO42-/ZrO2remarkablypromotedthehydroconversionofDSLCLRtoGC/MS-detectableOCOSsandarenes(includinghydroarenesandsubstitutedarenes),respectively.AcknowledgementsThisworkwassupportedbytheSpecialFundforMajorStateBasicResearchProject(Project2004CB217601),NationalNaturalScienceFoundationofChina(Project20676142),theProgramoftheUniversitiesinJiangsuProvinceforDevelopmentofHigh-TechIndustries(ProjectJHB05-33).ReferencesBasaran,Y.,Denizli,A.,Sakintuna,B.,Taralp,A.,andYurum,Y.2003.Bio-liquefaction/solubilizationoflow-rankTurkishlignitesandcharacterizationoftheproducts.EnergyFuels17(4):1068-1074.Gao,Z.,Chen,J.M.1994.StudiesonSO42-/TiO2andSO42-/Fe2O3solidsuperacidsystems.Chem.J.ChineseUniv.15(6):873-877.Gao,Z.,Chen,J.M.,andTang,Y.1992.StudiesontheformationofZrO2/SO42-superacidsystem.Chem.J.ChineseUniv.13(12):1498-1502.Pradhan,V.R.,Herrick,D.E.,Tierney,J.W.,andWenderI.1991.Finelydispersediron,iron-molybdenum,andsulfatedironoxidesascatalystsforcoprocessingreactions.EnergyFuels5(5):712-720.Sartori,G.,Ballini,R.,Bigi,F.,Bosica,G.,Maggi,R.,andRighi,P.2004.Protection(andDepr-otection)offunctionalgroupsinorganicsynthesisbyheterogeneouscatalysis.Chem.Rev.104(1):199-250.Sasaki,M.,Kotanigawa,T.,andYoshida,T.2000.LiquefactionreactivityofmethylatedIllinoisNo.6coal.EnergyFuels14(1):76-82.Shimizu,K.,Karamatsu,H.,Iwami,Y.,Inaba,A.,Suganuma,A.,andSaito,I.1995.Solubilizationoflignitewithsuperacid(trifluoromethanesulfonicacid)/isopentaneatthemildconditions.FuelProcess.Technol.45(2):85-94.Shimizu,K.,Kawashima,H.1999.Comparisonofsuperacid-catalyzeddepolymerizationthermaldepolymerizationofbituminouscoals-catalysisbysuperacidHF/BF3andsyntheticPyrite.EnergyFuels13(6):1223-1229.Shimizu,K.,