Separation-Process-Principles1

SeparationProcessPrinciplesJ.D.Seader,ErnestJ.HenleyLecturer:TaoZhouCentralSouthUniversityAbouttheAuthors•J.D.SeaderisProfessorofChem.Eng.attheUniv.ofUtah.HereceivedB.S.degreesfromtheUniv.ofCaliforniaatBerkeleyandaPh.D.fromtheUniv.ofWisconsin.From1952to1959,SeaderdesignedprocessesforChevronResearch,andfrom1959to1965,heconductedrocketengineresearchforRocketdyne.BeforejoiningthefacultyattheUniversityofUtah,hewasaprofessorattheuniversityofIdaho.Combined,hehasauthoredorcoauthored102technicalarticles,sixbooks,and4patents,andalsocoauthoredthesectionondistillationinthe6thand7theditionsofPerry’sChemicalEngineers’Handbook.SeaderhasbeenatrusteeofCACHEfor26years,servingasanexecutiveofficerfrom1980to1984.For20years,hedirectedtheuseanddistributionofMonsanto’sFLOWTRANprocesssimulationcomputerprogramforvariousuniversities.SeaderalsoservedadirectorofAIChEfrom1983to1985.In1983,hepresentedthe35thAnnualInstituteLectureofAIChE,andin1988,receivedthecomputinginChemicalEngineeringAwardoftheCASTDivisionofAIChE.•ErnestJ.HenleyProfessorofChemicalEngineeringattheUniversityofHoustonB.S.UniversityofDelawareDr.Eng.Sci.ColumbiaUniversity1953-1959ProfessoratColumbiaUniversity.HealsohasheldprofessorshipsatStevensInstituteofTechnol.,Univ.OfBrazil,StanfordUniv.,CambridgeUniv.,andCityUniv.ofNewYork.Heauthoredorcoauthored72technicalarticles,12books,and9patents.For17years,hewasatrusteeofCACHE,servingasPresidentfrom1975to1976anddirectingtheeffortsthatproducedthe7-volumesetof“ComputerprogramsforChem.Eng.Education”andthe5-volumeset“AIChEModularInstruction”.Asactiveconsultant,heservesontheBoardofDirectorsofMaxximMedicalInc.,ProcedyneInc.,LasermedicsInc.,andNanodyneInc.Chapter1SeparationProcessesThechemicalmixturesareseparatedintotheirconstituents,asanart,formillennia.Earlycivilizationsdevelopedtechniquesto(1)extractmetalsfromores,perfumesfromflowers,dyesfromplants,andpotashfromtheashesofburntplants,(2)evaporateseawatertoobtainsalt,(3)refinerockasphalt,and(4)distillliquors.Thehumanbodycouldnotfunctionforlongifithadnokidney,amembranethatselectivelyremoveswaterandwasteproductsofmetabolismfromblood.Separations:enrichmentconcentrationpurificationrefiningisolationAreimportanttochemistsandchemicalengineers.Chemistsuseanalyticalseparationmethodssuchaschromatography,todeterminecompositionsofcomplexmixturesquantitatively.preparativeseparationtechniquestorecoverandpurifychemicals.Chemicalengineersaremoreconcernedwiththemanufactureofchemicalsusingeconomical,large-scaleseparationmethods,whichmaydifferconsiderablyfromlaboratorytechniques.Forexample,inalaboratory,chemistsseparateandanalyzelight-hydrocarbonmixturesbygas-liquidchromatography,whileinalargemanufacturingplantachemicalengineerusesdistillationtoseparatethesamehydrocarbonmixtures.Thisbookpresentstheprinciplesoflarge-scalecomponentseparationoperations,withemphasisonmethodsappliedbychemicalengineerstoproduceusefulchemicalproductseconomically.Includedaretreatmentsofclassicalseparationmethods,suchasDistillationAbsorptionLiquid-liquidextractionAswellasnewermethods:adsorptionandmembraneseparationSeparationoperationforallthreephases(gas,liquid,andsolid)arecovered.Knowingtheprinciplesofseparationoperations,chemicalengineerscansuccessfullydevelop,design,andoperateindustrialprocesses.1.1Industrialchemicalprocesses•Thechemicalindustrymanufacturesproductsthatdifferinchemicalcontentfromprocessfeeds,whichcanbe1)naturallyoccurringrawmaterials,2)plantoranimalmatter,3)chemicalintermediates,4)chemicalsofcommerce,or5)wastesproducts.•Especiallycommonareoilrefineries,whichproduceavarietyofusefulproducts.Typicalprocessesaredistillationtoseparatethecrudeoilintovariousboiling-pointfractionsorcuts,alkylationtocombinesmallhydrocarbonmoleculesintolargermolecules,catalyticreformingtochangethestructureofmedium-sizehydrocarbonmolecules,fluidcatalyticcrackingtobreakapartlargehydrocarbonmolecules,hydrocrackingtobreakapartevenlargermolecules,andotherprocessestoconvertthecrude-oilresiduetocokeandlighterfractions.OilrefineryCrudeoilCleanfuelgasLPGSulfurMotorgasolineDieselfuelJetfuelLubricantsWaxesFueloilsCokeAsphaltFigure1.1Refineryforconvertingcrudeoilintoavarietyofmarketableproducts•Achemicalprocessinvolvesdifferentmodesofoperation,conductedineitherabatchwise,continuous,orsemicontinuousmanner.Theoperationsmaybeclassifiedaseitherkeyoperations(whichareuniquetochemicalengineeringbecausetheyinvolvechangesinchemicalcomposition):(1)chemicalreaction,(2)separationofamixtureofchemicals.orauxiliaryoperations(whicharenecessarytothesuccessofthekeyoperationsbutmaybedesignedbymechanicalengineersaswellbecausetheauxiliaryoperationsdonotinvolvechangesinchemicalcomposition):(1)separationofphases,(2)heatadditionorremoval,(3)shaft-workadditionorremoval(tochangepressure),(4)mixingordividingofstreamsorbatchesofmaterial,(5)solidsagglomeration,(6)sizereductionofsolids,and(7)separationofsolidsbysize.Blockflowdiagramsareusedtorepresentchemicalprocesses.Considerablymoredetailisshowninprocessflowdiagrams,whichalsoincludeauxiliaryoperationsandutilizesymbolsthatdepi