低甲醇含量甲醛水溶液的精馏过程研究

2822001JOURNALOFBEIJINGUNIVERSITYOFCHEMICALTECHNOLOGYVol.28,No.220011)2)1)(1),132021;2),100029):,22,2,2NRTLPRO/II,;30%(),10m;:22;;;:TQ050.4:2000203216:,1966,,22,VLE(vapor2liquidequilibrium)[16],,,,[5]22VLE,22,,22VLE[16],Maurer(1986)VirialVLE[2]Brandani(1991)Maur2erUNIFAC[3][4],,,,,,,1%,2222VLE,,122VLE3,,,,,ij=KiKj=yi/xiyj/xj(1):Ki,Kjij;yi,yjxi,xjij2[1],122,12,,222,,3,2,1[1]Fig.1Variationofrelative2volatilitywithtemperature12VLE[1]Table1VLEdataandrelative2volatilityofformaldehyde2watert/x1y1129916010334010330019876981601091501080801872797180112510111400189989715011825011452017609971201236101156301599411,2,213615,2;2,212511,2;21,2,716710-30,516710-30610010-30(Cm),,,,,2,,222VLE,iyip=xiipsatiexpVLm,iRT(p-psati)(2):p,Pa;ii;psatii,Pa;VLmi,m3mol-1;T,K;R,81314510m3Pamol-1K-1NRTL(2)lni=NjjiGjixiNkGkixi+NjxiGijNkGkjxkij-NkxkkjGkjNkGkjxk(3):iGijNRTL[7][7]NRTL,[7]DECHEMA,504VLE52(),NRTL4013%2VLE[7]Table2SutbilitiesofactivitycoefficientmodelsfororganicsoulutionVLE/%Margularsvan1413Laar711Wilson2410NRTL4013UNIQUAC14132211SimulationSciencePRO/II,,10()15002125500kg/h;80;0113MPa(A);(812001)01370107011201510156,()0199,010150,,CHEMIDISTCHEMIDIST33Table3TypicalresultsofsimulationNQc/(GJh-1)Qb/(GJh-1)R11282617083526164391615214881381681317291831410510240419596510,3,2,3(a)3(b),42Fig.2Temperaturedistributionwiththeoreticplatenumber2132,(,),3,4,,w()w(),w3(a)Fig.3(a)Densitydistributionofliquidandvaporwiththeoreticplatenumber3(b)Fig.3(b)Massflowratedistributionwiththeoreticplatenumber4Fig.4Compositionsdistributionofliquidandvaporphasewiththeoreticplatenumber()w()w(),w()137,w()710w(),w(),w(),281127912:,,25Fig.5Flowparameterdistributionwiththeoreticplatenumber3,()[8]F=qmqmGL(4):qm,kg/h;qm,kg/h3,5010337;010854,22,,[9],2(MELLAPAK350),,,[10],,,,,30%;10m;0125%,()01020101;3%();,422,VLE,,2,,,2NRTL,PRO2,,FPGji,Gki,Gkj,GijNRTLKiiq,kgh-1qm,kgh-1qm,kgh-1p,Papsatii,PaVLm,ii,m3mol-1R,81314510m3Pamol-1T,Kwiixiiyiiijijii,kgm-3G,kgm-3L,kgm-3ij,ji,kjNRTL[1]Pergamon.Handbookofvapor2liquidequilibriumdataatnormalpressure.London:Oxford,1979.473480,553554[2]MaurerG.Vapor2liquidequilibriumofformaldehydeandwater2containingmulticomponentmixtures.AIChEJour2nal,1986,32(6):932935022001[3]BrandaniS,etal.Aphysicaltheorysuperimposedonthechemicaltheoryfordescribingvapor2liquidequilibriaofbinarysystemsofformaldehydeinactivesolvents.IndEngChemRes,1991(30):415417[4],,.2.,1996,10(3):225230[5]WalkerJF.Formaldehyde,AmericanChemSocietyMonographSeries,1953.164166[6]..:,1993[7]SM..,,.:,1991[8]BravoJL.Selectstraturedpackingsortrays,ChemEngProg,1997,36(7):3941[9]BravoJL.Columninternals2Maximumefficiencyindis2tillationabsorption,strippingandextraction.ChemEng,1998(2):7677,7980[10]..:,1998.8485Distillationprocessofformaldehydeaqueoussolutionwithlow2contentmethanolJIANGWen2shu1)ZHENGDan2xing2)WANGXi2qiang1)(1)FertilizerFactoryofJilinChemicalIndustryCo.,Ltd.,Jilin132021;2)CollegeofChemicalEngineering,BeijingUniversityofChemicalTechnology,Beijing100029,China)Abstract:Apointofviewisproposedaftertheoreticanalysis.Whenthemethanol2formaldehydeaqueoussolu2tionisseparated,methanoliscomparativelyeasiertovolatilize,andthesystemappearstobeakindofthevapor2liquidequilibriumfeature,namely,theseparationofmethanolvs.formaldehyde2watermixturehasdominantef2fect.TheNRTLthermodynamicmodelwasselectedinthePRO/IIoptimumsimulationcalculationsofthedis2tillationprocess.Asolutionoftheproblemcanbeattainedaccordingtotheconvergencespecification.Basedonthesimulatedresults,theengineeringimplementchoosingthestructured2packingtowershowsthatthetechnicaltargetisimprovedmarkedly,thetreatmentcapabilityisincreasedby30%,thecolumnheightfallsoffabout10mandthefinanceevaluationisgood.Keywords:methanol2formaldehydeaqueoussolution;vapor2liquidequilibrium;processsimulationofdistilla2tion;structured2packingtower,420,:156122: