催化裂化提升管反应器数学模拟新方法

:2000-11;:2001-01-18:1999:(196419-),,,,,:,:(,102249):,,,,,,,,,,,,:;;;;:TE62414+1:A:100124160(2001)0221112116ANewMathematicalModelingApproachforFluidCatalyticCrackingRiserReactorsGAOJin2senXUChun2mingLINShi2xiongYANGGuang2hua(StateKeyLaboratoryofHeavyOilProcessing,UniversityofPetroleum,Beijing,102249)Abstract:MathematicalmodelsforFluidCatalyticCracking(FCC)riserreactorswerebuiltgenerallyonthebasisofassumptionofplugflowpatternwithinrisers.However,somerectificationhastobemadebyso2calledunitfactorswhentheywereusedtocommercialFCCunits.Themodelsexhibitedmuchmoreempirical.Theyshouldntbesobecauseabasicandcompletedescrip2tionontheFCCchemicalreactionmechanismaregivenandmodelparametersarephysicallymeaningfulratherthanempiricalwhenestablished.WebelievethatthereasonthatresultsinthiskindoftheoreticalretrogressionispredominantlytomodelflowpatternsoftheFCCreactorsone2dimensionallybecausetherealityisanothercase.Inadditiontothecomplexcatalyticcrackingreactions,theflowpatternofoilandcatalystsinsidereactorsisverycomplicated,whichisfarawayfromtheidealpistonflow.ThissortofmodelingontheFCCriserreactorsdidnottaketheflowandheattransferpatternintoconsideration.Therefore,wehavecarriedoutsomeresearchestoaimatchangingtheundesiredsituation.AnewmathematicalapproachwasproposedtomodeltheFCCriserreactors,whichiscalled32dimensionaldifferentialsimulation.Thisapproachcompletelytooktheriserreactorstructures,fluidin2letconditionsandtheflowpatternsaswellasheattransfersintoconsideration.Ageneralflow2reactionmodelfortheFCCriserre2actorshasbeenbuiltbyintegratinggas2solidflow,heattransfer,catalyticcrackingreactionsandturbulentfluctuationintoit.ItcanbesolvedwiththeapplicationofSIMPLEalgorithm.Thenvelocityandtemperaturedistributionsofgas2particletwo2phaseandgaseouscomponentdistributionsinsidetheFCCriserreactorscanbepredictedouttorevealthechemicalengineeringdetailsofFCCriserreactors.ThesedataareindispensableforthedesignoftheFCCriserreactorsandtheoperationoptimizationofacommercialFCCriserreactorthatisinoperation.TheyalsoarenecessarytotheimplementationofsomenewtechniquesfortheFCCriserre2actors.Keywords:catalyticcracking,riserreactor,mathematicalmodeling,two-phaseflow,heattransfer1822001328ComputersandAppliedChemistryVol118,No12March,20011:Blanding,,,,,,,,,,,,,,2Blanding[1],,:C100-C=kPSw(1),Blanding:X=C100-C=FPFSWFTFAFCFF(2),[2,3,4,5],WeekmanWei[6](Lumping),[7,8]:,,,:5Y15t+UV5Y15X=-R1(Y1,t)(3)5Y25t+UV5Y25X=1R1(Y1,t)-R2(Y2,t)(4),Weekman[9],,,:5(aj)5t+GV5aj5x=rj(5)rj=(tC)1+KhCAh(c/)k(aj)(6)(6),jrjj(aj),(c/)(tc)/(1+KhCAh):dˆadx=11+KAhCAhPMWRT(tC)SwhKˆa(7),Paraskos[10]Yen[11]Liang2SunLee[12][13-16][17]21118[18],,,(3)-(6),(7),,,,,[19-22]:(1),;(2),,;(3),,,,,(3)-(5)R1R2rj,,,,,[23,24]5,,Avidan[25]Rj,:Cj=Aj0+Ajne-n(8),:Cj=Aj0+Ajn(nt)(9),Gates[20]Weekman,,,:dY1dX=-K0SY21+Exd2Y1dX2(10)Ex,:Y1=11+(K0/S)(1-2Ex)Y01(11)=1-Y1K0/S1+K0/S(12)Y01=(1+ExK0/S)-1(13),,,,(),,,,,,,,3,,,,3112:,,,,,,,,[26]:55t(Riii)+55x(Riiuii)+5r5r(rRiivii)+5r5(Riiwii)=55xi5i5x+5r5rri5i5r+5r25i5i5+Si(14)1,Si,,kkp[27],,k-,[28,29],,,(14)PatankarSIMPLE[30],,(14),:aPP=aEE+aWW+aSS+aNN+aLL+aTT+b(15)(15)TDMA,,,,,,,,,,4,[31]16(3,1P,1k,1,1,9),7(3,1kp,1,2),,,12,[32],:,34[33],,,,,,,,,411181Fig11Flowfieldsofthegasandparticlephasesatvariousaxialsecionsofriserreactor,a-acrossfeednozzle,b-/4fromfeednoz2zle,c-/2fromfeednozzle2Fig12Contourdiagramofcatalystconcentration(kg/m3)atvariouscrosssectionsacrossfeednozzles3Fig13Compositiondistributionofgasphasealongtheriserreactorheight4Fig14Variationofgaseoustemperatureintheriserbeforeandafterinjectingwater5,,,,,,,,,,Ajo,Ajna,mol-j/g2gasa1ajj,mol/g2gasaE,aW,aS,aN,aL,aTpaPPbCCAh,wt%ExFAFCFFFPFSWFTGV,g/cm21hi-g,pK,(g2cat/cm3)-1h-1K0,(gcat/cm3)-1h-1kk,m2/s2Khkp,m2/s2MwP,atmR,82115atmcm3/molKrjjR1,R2s,sw,swh,h-1t,stC,sST,KUV,m/su,m/s5112:v,m/sw,m/sXxY1Y2,m2/s3(tc)E,W,S,N,L,TP,n,kg/m3(t)(nt)(t)Laplace1BlandingFH.Reactionratesincatalyticcrackingofpetroleum.IndEngChem,1953,45(6):1186-11932PierceWL,SoutherRP,KaufmanTG,RyanDF.Innovationinflexicracking.JHydrocarbonProcess,1972,51(5):923WollastonEG,HaflinWJ,FordWD,DsouzaGJ.Whatinfluencescatalyticcracking.JHydrocarbonProcess,1975,54(9):934..,1984,(7):21-235..,1981,2(1):111-1216JamesW,PraterCD.AdvancesinCatalys.NewYork:AcademicPress,1962:203-3927WeekmanVWJr.Amodelofcatalyticcrackingconversioninfixed,moving,andfluid2bedreactors.IndEngChem,ProcessDesDev,1968,7(1):90-958WeekmanVWJr,NaceDM.Kineticsofcatalyticcrackingselectivityfixed,moving,andfluidbedreactors.AIChEJ,1970,16(3):397-4089JacobSM,GrossB,VoltzSE,WeekmanVWJr.Alumpingandreactionschemeofcatalyticcracking.AIChEJ,1976,22(4):701-71510ParaskosJA,ShahYT,McKinneyJD,CarrNL.Akinematicmodelforcatalyticcrackinginatransferlinereactor.IndEngChemProcessDesDev,1976,15(1):165-16911YenLC.ReactionkineticcorrelationforpredictingcokeyieldinFCC.Oil&GasJ,1988,82(6):6712LeeL,ChenY,HuangT,PanW.Four2lumpkineticmodelforfluidcatalyticcrackingprocess.CanaJofChemEng,1989,67:61513,,,,,.().(),1985,1(1):314,,,,.().(),1985,1(3):4715,,,,.().(),1985,1(4):1116,,,.().(),1988,3(4):1817..,199218,,,..,:,1995:145-15319..(