DOC

Production of propene from 1-butene metathesis reaction on tungsten based heterogeneous catalysts

By Todd Rice,2014-02-18 12:34
6 views 0
Production of propene from 1-butene metathesis reaction on tungsten based heterogeneous catalystsof,on,from,based

    Production of propene from 1-butene

    metathesis reaction on tungsten based

    heterogeneous catalysts Availableonlineatwww.scienCedirect.corn

    

    

    :ScienceDirect

    JournalofNaturalGasChemistry18(2009)331-336

    JOURNALOF

    NATURALGAS

    CHEMISTRY

    1v,v.elsevier.com/locate/jngc

    Productionofpropenefrom1-butenemetathesisreactionon tungstenbasedheterogeneouscatalysts

    HuijuanLiu,LingZhang,XiujieLi,ShengjunHuang,ShenglinLiu,

    WenjieXin,SujuanXie,LongyaXu

    .

    StateKeyLaboratoryofCatalysis,DalianInstituteofChemicalPhysics,ChineseAcademyofSciences,Dalian116023,Liaoning,China

    2.GraduateUniversityofChineseAcademySciences,Beijing100049,China [ReceivedFebruary20,2009;RevisedMarch24,2009;AvailableonlineAugust14,2009J Abstraet

    Anewpropeneproductionroutefroml

    butenemetathesishasbeendevelopedonheterogeneous10W03/A1203

    HYcatalystswithdifferentHY

    contents.Itisfoundthatthecatalystsplaybifunctionallyfirstfortheisomerizationofl

buteneto2.buteneandthenforthecrossmetathesis

    between1buteneand2

    butenetopropeneand2-pentene.ThecombinationofHYzeoliteandA1,Oisprerequisitefort

    heproductionof

    propene.ThepropeneyieldkeepsincreasingwiththeHYcontentintherangeof10

    70wt%.where10WO3/AI20370HYexhibitsthehighest

    propeneyield.TheMSH,TPRandMSO2

    TPOcharacterizationsindicatethattheincreaseofHYcontentinthecatalystsweakensthe

    interactionbetweenWspeciesandsupports.whereasenhancetheprobabilityofcokingonthe

    metalspeciesandacidsites.

    Keywords

    propene;1-butene;metathesis;10WO3/A1203xHY;bifunction

    1.Introduction

    Demandforpropeneduetotheincreasingdemandof

    propenederivativesisgrowingrapidlyinworldwidechem

    istry.Thetechnologyofpropeneproductionfromolefin metathesishasbecomeamajorfocusresearchinrecent"fears, suchastheLummusABBprocess,whichconvertsetheneinto propenethroughcross..metathesiswith2..butenesoverahet.. erogeneousmetathesiscatalystn-41.

    Accordingtoreactionequationsbasedonwidelyaccepted carbenemechanism,propenecanbeobtainedonlybetween theterminalandinternalalkenes..e.1buteneand2butene.

    Fortherecentpublishedresultsf51,propenecannotbeob. tainedbypure1butenefeedoverhomogeneousGrubbsfirst generationtyperutheniumcatalysts.Asaresult.thecommer. cialapplicationofPhillipsTriolefinProcess(nowlicensedas ABBOCT)andShellHigherOlefin(SHOP)usedisomeriza tioncatalystssystemtoget2butenefrom1buteneorethene

beforethemetathesisreaction41.

    Analternativewaytoproducepropeneistheauto.

    metathesisof1.buteneoverbifunctionalcatalystswithboth isomerizationaswellasmetathesisactivity.Inthislight. metaloxide(MoO3orW0)supportedonacidicalumina

    zeolitecompositecanbeacandidatefortheproductionof propenefrompure1butene,

    Theaimofthepresentworkistoreportahetero2eneous

     catalyst,.e.10WO/A1,03.HY.aswellasitscatalyticperfor

    manceinthe1butenemetathesisreaction.Aseriesofcata

    lystswithdifferentHYcontentsinsupportareevaluated.The resultsindicatethatthecatalyticperformancesareremarkably influencedbyHYcontentin10W0/Al,03.HYcatalysts. Thepropenemolaryieldcanachieve2l%andl9%on

    10WO3/30%Al203-70%HYand10WO3/50%A120350%HY

    respectively.TheinitialcatalyticactivityCallbecorrelated withthestateoftungstenoxidespeciesasafunctionofHY content.Furthermore,thecokingbehaviorevidencedbyTPO profilesiscloselyassociatedwiththetransformationoftung

    stenoxidesandacidityofthecatalysts,whichwillleadto remarkablydifferentstabilityinthemetathesisreaction. 2.Experimental

    2..Catalystpreparationanditsevaluation

    A1203HYsupportwaspreparedbyextrudingamixture 0f1A1203powderandHYzeolite(WenzhouZeoliteManu

    Correspondingauthor.Tel:+8641l-84693292;Fax:+86411-84693292;E

    mail:lyxu@dicp.accn

    ThisworkwassupportedbytheNationalNaturalScienceFoundationofChina(No.2077312

    0)andNational973ProjectofChina(No.2005CB221403) Copyright~2009,DalianInstituteofChemicalPhysics,ChineseAcademyofSciences.Allfi

gh~reserved.

    doi:10.1016/S10039953(08)60113-9

    

    332HuijuanLiueta1./JournalofNaturalGasChemistryVo1.18No32009 factureofChinaSi/A17=10,Na2O<O.2wt%)atdesirable weightpercentintostripswithadiameterofabout2mm.The drawnextrudatewasleftatroomtemperatureforafewhours andplacedinanovenat393Kfor12h.Subsequently,the driedextrudatewascalcinedat773Kfor2handthenground into1632mesh.

    Catalystscontaining10wt%tungstenwerepreparedby impregnationoftheA1203HYsupportwithammonium

    metatungstatesolutionaccordingtotheincipientwetness method.Theimpregnatedsamplesweredriedat393Kfor 5h,andthencalcinedat873Kfor2h.Thesepreparedcat

    alystsaredenotedas10WO3/A1,OzHY1whereindicates

    theweightpercentofHYzeoliteintheA1203HYsupport.

    Thecatalystswereevaluatedinafixedbedflowmicro

    reactorofl0mminnerdiameter.and3gofcatalystwithan averageparticlesizeof0.561.3mmwasloaded.AnEU2

    typethermocouplewasfixedinthemiddleofthecatalyst bedandtakenasthereactiontemperature.Beforeevalua

    tion,thecatalystswerepretreatedat773Kinhighpurity N,(30ml/min)for1h.thenitwascooleddowntothede

    siredreactiontemperature.Thetypicalreactionconditionsare asfollows:temperature=453K.pressure=0.1MPa;WHSV rlC4H8)=1.5h.andcatalyst=3.0g.Thereactionprod

    uctsareanalyzedbyaVarian3800gaschromatograph equippedwithallFIDdetectoranda50mA12O3plotcolumn.

    2.2.Productanalysis

Reactionof1-buteneon10WO3/A1203zHYcatalysts

    y(c)×

    mayincludeisomerization,self-metathesis,secondmetathesis reactionandpossibleolefinoligomerizationasshownbelow: Scheme1.Schemeofisomerization,self-metathesis,secondmetathesisre-

    actionandpossibleolefinsoligomerization

    ItiShardtomakeacomprehensivelistofal1thereactions andproductsduetothecomplicatedsidereactionsandcross

    metathesisreactions.GCresultsindicatethatcistrans-2

    penteneandcis.'arts3hexenearethemajorproductsfor

    CandCcomponent.Forasimpletreatment,wedenote productswiththesamecarbonnumberasC,wherenrepre

    sentscarbonnumber.Atthesametime.alltheheavyproducts inC7C10rangearedenotedasC74.

    The1buteneconversionisdeterminedbythemassper- centageintheexhaustgas,andthemolaryieldofproductsis calculatedbythefollowingequation:

    w(cx)

    —————————————————

    !L——————————

    w(c~-)w(c)w(c2).(c)(c).w(c)(c)

    If一十——一十——_4一十——一十—十——一十——一

    Intheformula,l,(C)istheyieldofolefinwithcarbon number,Xisthelbuteneconversion,and(C)denotes

    masspercentofalkenecomponentwithdifferentcarbonnum

    bern.

    2.3.Catalystcharacterization

    XraydifiractionfXRD1measurementsweremadewith anX'pertPR0/PANalyticalDiffractometerusingCura

    diationandoperatedat40kVand40mA,withascanning

    speedof5./min.Patternswererecordedfrom5.to70.f20). Under10%H,/Arflowr20ml/min).H2TPRprofiles

    wereobtainedintherangeofambientto1073Katapro

    grammedtemperaturerateofl4K/minafterthesampleshad beenpretreatedinanArflowat773Kfor30min.There

    ductionwasmonitoredbyOMS(oministar)instrument,using thefragmentswithm/eof18astherepresentativeofwater whichwereformedfromoxidationofH2.

    Cokedepositiononspentl0W03/A1203zHYcatalysts

    wasdeterminedbytemperatureprogrammedoxidationfO2

    TP0).0.08gsamplewas1oadedintoaUshapedquartz

    microreactor.Thecatalystwasheatedfrom323to1123Kin a10%O2/Arstream.Theheatingratewasl0.C/rain.andthe O2/Arflowratewas50mgmin.Thecarbonwasmonitoredby QMS(oministar)instrument,usingthefragmentswithm/eof 28and44astherepresentativeofcarbonmonoxideandcar

    bondioxide.

    3.Resultsanddiscussion

    3..CatalyticpermanceofIOWO3/A1203xHYcatalysts

    T_ab1e1showstheactivityandselectivityof10WO31 A12O3-HYcatalystsasafunctionofHYzeolitecontent.The catalyticperformanceofcatalystsdependsonHYcontentin thesupport.Althoughallthecatalystsexhibithigh1butene

    conversion.eproductdistributionsarequitedifferent. 10WO3,Al203proceedsmetathesisreactionwith88.9% 1buteneconversionat453K.whilethetotalmetathesisactiv

    itvisverypoorwih0.5%molaryield.Theprimaryproducts arecis2buteneandtrans2butene.indicatingthepredomi

    nanceofisomerizationreaction.Thisisinfairagreementwith

referenceresults.whichalwaysreportpoorlowmetathesisac

    tivityforW03/2/A1203underrelativelymildconditions[1.

    Aremarkablechangeindistributionsofproductshasbeenob

    JournalofNaturalGasChemistryVo1.J8No.32009 servedwithincreasingHYcontents.AsshowninTable1. 1buteneconversiononl0W03/A1,03l0HYslightlyin

    creasesto93.3%.whilepropeneyieldachieves9.8%.Inthe rangeof10wt%-70wt%HYcontent.thepropeneyieldkeeps increasingwithhigherHYcontent.Themaximumpropene yieldof21.4%belongsto10W0/Al,0370HHowever,

    furtherhigherHYcontentwillleadtoadecreasedyieldas 18.6%on10W03,Al,0390HYAsanotherextremeexam

    ple.thepropeneyieldon10W03/HYdramaticallydecreases to1.4%.Upontheactivel0W03,A1'03HYcatalysts,C

    333

    andCyieldsarearound20%and15%,whereasCand C2yieldsareiustaround1%and5%,respectively.This suggests1butenemetathesisdoesnotproceedthroughself- metathesisreactionbutthroughcross..metathesisroutebe.. tween1buteneand2butene.Suchlowetheneyieldalsosug

    gestsconsumptionofthisproductbysuccessivesecondary crossmetathesisreactions.Asacomparison,theyieldof propeneisquitehigherthanthatofassociatedCprod

    ucts,whichissupportiveforthecontributionfromcross metathesjsreactjons.

    Table1.Reactionperformanceof10WO3/AI203-xHYwithdifferentHYcontents

    Reactionconditions:T:453K:P=01MPa;WHSV=1.5hl:timeonstream=lh Thepropeneyieldofl0WO3/A1203HYcatalystsasa

    functionoftimeiscomparedinFigurelfa).Lowyields f<10%1arestillobservedon10W03/Hl0W03/Al203,and

10W03/Al,0310HYwithextendedreactiontimeofl0h.

    Whereasfortheactive10W0/Al203-zHY(30wt%-90wt% HY)catalysts,propeneyieldincreasedintheinitial5hon eachsample.indicatingthepresenceof"inductionperiod". The"inductiontime"wasalsoobservedonW03/Si02.in

    dicatingaperiodwasneededtoformactivemetalcarbene

    speciesf11.Butsuchphenomenawerenotobservedin metathesisofetheneand2butenewiththesameWO3/Ah03

    HYcatalystsf61.Althoughthereasonisnotclear,ismay

    suggestthedifferenceintheinteractionbetweensubstrate alkenesandtungstenoxidespeciesfortheinitialfelrmation ofactivemetalcarbenespecies.

    Figure1fadisplaysthatthemaximumpropeneyieldof 25%belongsto10W03,A1,0370HYaftertheinitialin

    ductionperiod.However,thepropeneyieldonthecata

    Timeonstream(h)

    90

    80

    70

    50

    3O

    1ystsharplydecreasesafter17hrunningtime.andonly5% yieldcanbeobtainedat30htimeonstream.Asacom

    parison.catalystswith1owerHYcontentshowbetterstabil

    itydespitetheirslightlylowerinitialmetathesisactivity.For example.thepropeneyieldon10WO3/A120350HYcanstill

    achievel7%after30htimeonstream.Whileonthesame WO31A1203HYcatalystsforthemetathesisbetweenethene andbutenetopropene,thestabilityofcatalystincreaseswith

propeneselectivity6],indicatingtheotherdifferentreaction

    behaviorof1buteneonW03/Al,O3HYcatalysts. Sincepropeneisfromcross.metathesisbetween1butene

    and2butene.thevariationof2buteneyieldand1butene conversionwerealsocompared.

    2buteneyieldon10W03,A1'03and1OW0/A1703

    10HYarehighandstable.indicatingthetwocatalystsareac

    tirefor1buteneisomerizationreaction.The2buteneyield

    30HYand10W03,Ab050HYshowsal on10W03,A1,03

    mostthesametendency,onwhich2buteneyieldincreases 0

    1O0

    80

    70

    ?

    50

    40

    20300

    Timeonstream(h)

    2O30

    Timeoilstream(h)

    Figure1.Comparisonof10WO3/A1203xHYreactionperformance.(a)Propyleneyield,(b)2-buteneyield,(c)1-buteneconversion.(

    ?)l0WO3/AI203

    (.)10WO3/A1203IOHY,(?)10WO3/A120330HY,()10WO3/AI20350HY,(?)10WO3/A120370HY,(V)10WO3/A120390HY,(?)10WO3/HY 一奎0g0一?b>d0u0l

    一一0三一pluc0ln?_z

    gpl0I^uq2

    334HuijuanLiuetal/JournalofNaturalGasChemistryVol18No32009

    withtimeonstream.indicatingmore1-buteneconvertsto 2buteneonthesecatalysts.For10WO3/A120370HYand

    10W03/A12O3-90HY2buteneyielddecreasesfirstandthen increases.Asfor10W03/HYcatalysts,2-buteneyieldde

    creasesrapidlywithtimeonstream,suggestingafastdeacti

    vationonthecatalyst.

    Theinitial1buteneconversion0nvaFIOUScatalystswas closeto90%exceptalowervalueof80%onl0W03/H

    Themostdistinctdifferencewasobservedinthevariation Oflbuteneconversionasthefunctionoftimeonstream. 1buteneconversionsarequitestableon10WO3/A1203xHY

    withHYcontent1owerthan50%.However,higherHYcon

    tentwil1leadtoasharperdecreaseof1buteneconversion.

    Especiallyfor10W03/Hthe1buteneconversionundergoes

    asharpdecreaseto43%within10h.Atthesametimethe 2buteneyieldon10W03/HYdecreasescorrespondinglyto 40%in10h.Fromthesharpdecreaseof1buteneconver

    sionand2buteneyield.itisirifefredthatasignificantreduc

    tionofaccessibleacidsiteson10WO3/HYtakesplaceinthe processof1buteneconversion.thesearetheactivesitesfor doublebondisomerizationreaction[7,8].

    AsshowninFigurel(b)and(c),thedecreaseofHY contentinsupporteadstoimprovedperformanceforthe

    1buteneconversionandisomerizationto2butene.The1eSS

    activemetathesiscatalystsof10WO31A1203,10WO3/A1203

    1OHYandl0WO3/AI2033OHYgivehigherandmorestable

    2buteneyields.Whereas.suchisomefizationproductyields on10WO3/A120370HYand10WO3/A120390HYgradually

    increaseafterthedecreaseintheinitialreactionstage.

Report this document

For any questions or suggestions please email
cust-service@docsford.com