生物反應器細胞收集細胞破碎沉淀結晶純化產(chǎn)品制劑BioreactorExtractionCelldisruptionCellharvestingPurificationProductformulationPrecipitationandcrystallizationSupernatantPrecipitationandcrystallizationMembraneseparation

(MF)Membraneseparation

(UF/NF/RO)Membraneseparation

(UF/NF/RO)(ExtraCorporealMembraneOxygenation)人工肺，體外膜肺氧合技術ECMOmechanism不銹鋼膜陶瓷膜中空纖維膜聚合物卷式膜Chapter5

Membraneseparation5.1Introduction

5.2Membraneclassification5.3Membraneseparationprocess5.4Membranefouling（膜污染）5.5Membranemodules（膜組件）5.6Application5.7

Newmembraneseparationmethods5.1IntroductionDefinitionAmembraneisathinpermeable（有滲透性的）orsemi-permeablebarrier,whichallowsselectivepassageofdifferentspeciesthroughit,betweentwofluidstreamphases.Thisselectivityisutilizedforseparation.AdvantagesofmembraneseparationDisadvantagesofmembraneseparation(seeP76)AdvantagesofmembraneseparationMildoperatingconditionsSincenophasechangeisinvolvedtheenergyrequirementismodest.Thechemicalandmechanicalstressesontheproductareminimal.Theselectivitytowardsthedesiredproductisgood.Themethodcaneasilybescaledup.5.2MembraneclassificationSyntheticmembranescanbeclassifiedbyfunction,media介質,structureandgeometry幾何學.Functionpervaporation滲透蒸發(fā)(PV)hemodialysis血液透析(HD)electrodialysis電滲析(ED)ionexchange離子交換(IX)reverseosmosis反滲透(RO)nanofiltration納濾(NF)ultrafiltration超濾(UF)microfiltration微濾(MF)gasseparations氣體分離(GS)mediaormaterials

organicpolymer:e.g.celluloseacetate醋酸纖維素,polyamide聚酰胺,polyester聚酯

inorganicpolymer:e.g.ceramic陶瓷,metal.Geometry幾何學sometimesreferredtoas“form,”

film,hollowfiber中空纖維,tube管式Structurereferstothemicrostructureofthemembraneincrosssection橫截面Symmetric對稱;Asymmetric不對稱;Composite復合的各向同性微孔膜致密無孔膜帶電膜各向異性膜5.3membraneseparationprocessReverseosmosis反滲透Nanofiltration納濾Ultrafiltration超濾Microfiltration

微濾Dialysis透析Electrodialysis電滲析Pervaporation滲透蒸發(fā)Gasseparation氣體分離Table1ThestatusofallofmembraneseparationprocessesFlowschematicofamembranebloodoxygenator表5-1各種膜分離法的原理和應用范圍類型傳質推動力分離原理

應用舉例微濾（MF）壓差篩分菌體、細胞和病毒的分離、固液分離超濾（UF）壓差篩分蛋白質、肽、多糖的濃縮和純化，病毒的分離納濾（NF）壓差篩分水軟化、有機物和生物活性物質的除鹽和濃縮透析（DS）濃差篩分脫鹽、除變性劑反滲透（RO）壓差篩分鹽、氨基酸、糖的濃縮，淡水制造電滲析（ED）電位差離子遷移脫鹽、氨基酸和有機酸分離滲透蒸發(fā)（PV）壓差溶解擴散有機溶劑與水的分離，共沸物的分離（如乙醇濃縮）ReverseOsmosis(RO)Reverseosmosis

（反滲透）

apressuredrivenprocessaimedattheseparationofionicsolutes（離子溶質）andmacromolecules（大分子）fromaqueousstreams.ProcessDivingForce:Hydrostaticpressuredifference靜水壓力差atapprox.2-10MpaMembraneModules:spiral-wound,hollowfiber半透膜滲透壓somegeneralguidelinesformembrane

selectivityMultivalentions（多價離子）

areretainedbetterthanmonovalentions（單價離子）.Dissolvedgasessuchasammonia,carbondioxide,sulfurdioxide,oxygen,chlorineandhydrogensulfide(硫化氫)alwayspermeatewell.RejectionofweakacidsandbasesishighlypHdependent.whentheacidisintheneutralform,therejectionfalls.somegeneralguidelinesformembrane

selectivityRejectionofneutralorganicsolutesgenerallyincreaseswiththemolecularweight(ordiameter)ofthesolute.Componentswithmolecularweightsabove100arewellrejectedbyallreverseosmosismembranes.Negativerejectioncoefficients（系數(shù)）,thatis,ahigherconcentrationofsoluteinthepermeatethaninthefeedareoccasionallyobserved,forexample,forphenol（苯酚）andbenzene（苯）withcelluloseacetatemembranesApplicationofReverseOsmosisMembraneProcessIndustrialUseUltrapurewater,boilerwater,processpurewater,dailyindustriesDrinkingWaterSeawaterdesalination,brackishwaterdesalinationWastewaterTreatmentandReuseIndustrialwater,agriculturalwater,indirectdrinkingwater電阻率硅硼Flowschematicofatypicalbrackishwaterreverseosmosisplant.Theplantcontainssevenpressurevesselseachcontainingsixmembranemodules.Thepressurevesselsareina‘Christmastree’arraytomaintainahighfeedvelocitythroughthemodules.鹵水Biofouling（生物污染）themostseriousproblemintheoperationofSWRO（海水反滲透）plantstheusualmethodtopreventbiofoulingcontinuouschlorinedosingtointakeseawaterwithsodiumbisulfate(SBS,NaHSO4)dosingattheROportion.Membranesperformancedeteriorationoccurredbyoxidationincaseofbothpolyamide(聚酰胺)andcelluloseacetatemembranes,andbiofoulinghasnotbeensolvedyet.ViablecellcountassessmentinROplantForROmembranemodules,stableoperationisveryimportant.operationtroublesfouling(occupy80%)membranedeteriorationhardwareproblemsSolutions(1)properROmembraneelementswithlow-foulingproperty,(2)properpretreatmenttechnologybeforetheROmembrane,(3)suitablesterilizationmethodsandcleaningTrendsinROmembranetechnologylow-pressuremembranesforoperatingenergyreductioninthefieldofbrackishwaterdesalination.highwaterrecoverywithhigh-pressureresistanceinthelargeseawaterdesalinationmarket.TDS:總溶解固體(TotalDissolvedSolids)TrendsinROmembranetechnologyHighBoronRejectionSWROMembraneBoronexistsasboricacidinthenaturalwater.Potentialtoxicity：malereproductivetractdrinkingwater：below0.5mg/L(WHO,2004)ConventionalSWROmembrane：alittlemorethan90%ofboronrejection－－inadequateWhyisitdifficultforROmembranestoremoveboricacidinwater?SmallsizepKa:9.14–9.25;notionizedinnaturalseawater(pH7.0–8.0)thenexttarget:97or99%boronrejectionNanofiltration(NF)Nanofiltration(NF)apressure-drivenprocess.adifficultprocesstodefineandtodescribe.ProcessDivingForce:0.93-1.59MPaSpecificfeatureshavehighrejections(>90%)tomostdissolvedorganicsoluteswithmolecularweightsabove100–200veryhighrejectionsformultivalentions(>99%)Lowtomoderaterejectionsformonovalentions(0-70%)Nanofiltration(NF)Performancethreeparametersarecrucialfortheoperationofa(nano)filtrationunit:SolventpermeabilityorfluxthroughthemembraneRejectionofsolutesYieldorrecovery(40%~90%)ApplicationdrinkingwaterproductionConcentrationDesalting原生動物藻類膠體Ultrafiltration(UF)Ultrafiltration超濾

apressure-driven,permeability-basedmembraneseparationtechnique.mainlyusedforprocessingmacromoleculessuchasproteins,nucleicacids,andpolysaccharides.poresize:1-100nmProcessDivingForceHydrostaticpressuredifferenceatapprox.0.1-1.0MpaUltrafiltration(UF)mainseparationmechanism

size-basedsieving

butotherfactorssuchaselectrostatic（靜電）solute–membraneandsolute–soluteinteractionscansignificantlyaffectseparationmolecularmasscut-off(MWCO)

typicallydefinedasthemolecularweightoftheglobularproteinmoleculethatis90%rejectedbythemembrane.質量好的膜，應有陡直的截斷曲線，可使不同分子量的溶質分離完全；反之，斜坦的截斷曲線會導致分離不完全。一般選用的膜的額定截留值應稍低于所分離或濃縮的溶質的相對分子量。0.9MWCOA膜B膜溶質相對分子質量截斷曲線Ultrafiltration(UF)截留率R（rejection）表示膜對溶質的截留能力定義為R＝1－Cp／Cb式中Cp和Cb分別表示在某一瞬間，溶質在透過液（Permeate）和主料液（Bulk）的濃度。Thecut-offofultrafiltrationmembranesisusuallycharacterizedbysolutemolecularweight,butotherseveralfactorsaffecttheretentivity.theshapeofthemoleculethepHofthefeedsolution胃蛋白酶細胞色素c葡聚糖Ultrafiltration(UF)twomainissuesProductivity:Productivityisquantifiedintermsofthepermeateflux（滲透通量）,thisbeingdefinedasthepermeationrateperunitmembranesurfacearea.Selectivity

Howtomaintainahighpermeateflux?reducingsoluteaccumulationnearthemembranesurface(concentrationpolarization濃差極化)reducingadsorptionanddepositionofsolutesandotherfeedcomponentsonthemembrane(membranefouling)Methods:backflushing,creationofturbulence,introductionofgasbubblesMembranefouling-UFSurfacefoulingthedepositionofsolidmaterialonthemembranethatconsolidatesovertime.canbecontrolledbyhighturbulence（紊流）,regularcleaningandusinghydrophilicorchargedmembranestominimizeadhesiontothemembranesurface.generallyreversibleInternalfoulingcausedbypenetrationofsolidmaterialintothemembrane,whichresultsinpluggingofthepores.generallyirreversiblePurewaterflux:1cm3/cm2?minmacromolecularorcolloidalsolutionsflux:0.1cm3/cm2?minAtypicalcleaningcycle-UF1.Flushthesystemseveraltimeswithhotwateratthehighestpossiblecirculationrate.2.Treatthesystemwithanappropriateacidoralkaliwash,dependingonthenatureofthelayer.3.Treatthesystemwithahotdetergentsolution.4.Flushthesystemthoroughlywithwatertoremovealltracesofdetergent;measurethepurewaterfluxthroughthemembranemodulesunderstandardtestconditions.Evenaftercleaning,somedegreeofpermanentfluxlossovertimeisexpected.Iftherestorationoffluxislessthanexpected,repeatsteps1–3.Membranecleaningmethods-UFregularcleaningwithchemicalsolutionsmechanicalcleaningparticularlyifchemicalcleaningdoesnotrestorethemembranefluxSponge-ball:effectivebutrelativelytime-consumingprocess;infrequentlyBackflushing（反沖）anotherwayofcleaningheavilyfouledmembraneswidelyusedtocleancapillary（毛細管）andceramicmembranemodulesnotusuallyusedforspiral-woundmodulesBackflushingofmembranemodulesbyclosingthepermeateport.ThistechniqueisparticularlyapplicabletocapillaryfibermodulesmembranelifetimeUFalthoughregularcleaning,rarelymorethan2–3yearsmodulesmaybereplacedannuallyincheesewheyorelectrocoatpaintapplications.ROnormallycleanednotmorethanonceortwiceperyearandcanlast4–5years.ApplicationApplications:Concentration,purification,desaltingElectrocoatPaintFoodIndustry:Cheeseproduction,Clarificationoffruitjuice,Processwaterandproductrecyclingbiotechnologyindustry:enzymeproduction,cellharvesting,orvirusproduction鉻酸鹽/磷酸鹽電鍍池含鎳電鍍廢水中加入NaOH，產(chǎn)生類似生物大分子膠狀Ni(OH)2沉淀。乳清是工業(yè)生產(chǎn)干酪和干酪素的副產(chǎn)物，營養(yǎng)價值較高，含有豐富的蛋白質、乳糖以及多種礦物質和水溶性維生素等。毛細管式超濾膜原理內壓式超濾膜過濾原理外壓式超濾膜過濾原理FlowschemeofthemanufacturingprocessofEngerixBbulkFermentation→celldisruption→precipitation→clarification→ultrafiltration→columnchromatography→ultracentrifugation→columnchromatography→sterilefiltration→sterileHBsAg(purifiedbulkantigen)Microfiltration(MF)Microfiltration微濾

alowpressuremeansofseparatinglargemolecularweightsuspendedorcolloidal膠體的compoundsfromdissolvedsolids.ProcessDivingForce

Hydrostaticpressuredifferenceatapprox.10-500kPaApplications

Sterilefiltration無菌過濾cellharvestingfromfermentationbroths發(fā)酵液fractionationofmilkproteinscornsyrup玉米糖漿clarificationSterilefiltrationInatypicalenzymecellharvestandrecoveryprocess,microfiltration微濾replacesthecentrifugationandprecoat預涂filtrationstepsDialysisDialysisaconcentrationgradient

basedseparationprocesswhichusesasemipermeablemembranetoseparatespeciesbyvirtueoftheirdifferentrateofdiffusion

throughmembrane.ApplicationHemodialysis血液透析removalofwastemetabolites代謝物,excessbodywater,andrestorationofelectrolytebalance維持電解質平衡inblood)desaltingDialysisDialysisfordesaltingSelectadialysisbagtreatthedialysismembraneboilingindistilledwatercontainingEDTACheckforleaksaddtheproteinsolution,leavesomespaceattop(1/3volume).stirgentlybystirbaronamagneticstirrerchangethedialysisbufferintermittentlyCompletionStoragebeakerLowsaltbufferhighsaltsampleindialysisbagclipElectrodialysis(ED)Electrodialysis電滲析

anelectrochemicalseparation電化學分離processinwhichmineralsaltsandotherionicspeciesaretransportedthroughionselectivemembranesfromonesolutionintoanotherunderthedrivingforceofadirectcurrent(DC)electricalpotential直流電電勢差.Applicationsproductionofpotablewater

飲用水fromseaorbrackish含鹽的

water,electroplating電鍍

rinse沖洗

recovery,desalting脫鹽ofcheesewhey乳清,productionofultrapurewater超純水etc.Electrodialysis圖5-6電滲析原理（A-陰離子交換膜；C-陽離子交換膜）12435ACAC陽極陰極Electrodialysis

PervaporationPervaporationemploymembranesfortheselectiveseparationofdilutesolutesfromavapororliquidintoasolute-enrichedvaporphase.aphasechange相變occursduringtransportthroughthemembrane.Transportthroughthesemembranesiseffectedbymaintainingavapourpressuregradient蒸汽壓差

acrossthemembrane.PervaporationApplicationsseparationofethanol乙醇-watermixture,solventrecovery溶劑回收separationofheatsensitiveproducts熱敏感產(chǎn)物

orenrichmentoforganicpollutants有機污染物的富集etc.脫水滲透蒸發(fā)－分餾發(fā)酵精餾器MicrofiltrationMembraneDistillationPervaporationgasseparationDrivingforcethepressuredifferenceacrossthemembraneSeparationisachievedbecauseofdifferencesintherelativetransportratesofthefeedcomponents.Componentsthatdiffusemorerapidlybecomeenrichedinthelowpressurepermeatestreamwhiletheslowercomponentsareconcentratedintheretentateorresiduestream.SimplifiedflowschematicofthePRISMmembranesystemtorecoverhydrogenfromanammoniareactorpurgestream.Atwo-stepmembranesystemisusedtoreducepermeatecompressioncostsHELIUM氦氣為無色無味，不可燃氣體，空氣中的含量約為百萬分之5.2?；瘜W性質完全不活潑，通常狀態(tài)下不與其它元素或化合物結合。理論上可以從空氣中分離抽取，但因其含量過于稀薄，工業(yè)上從含氦量約為0.5%的天然氣中分離、精制得到氦氣。利用其－268.9℃的低沸點，液氦可以用于超低溫冷卻。Application氣球和飛艇人造空氣保護氣體：2000年美國消耗的所有氦氣中，有18%用在了焊接上，還有16%用作其他工業(yè)的保護氣。超低溫冷凍劑：氣冷式核反應堆的工作流體、衛(wèi)星發(fā)射、導彈武器工業(yè)、低溫超導研究、半導體生產(chǎn)等方面具有重要用途。Production氦氣最主要的來源是天然氣。天然氣中最高則可含7.5%的氦，是空氣的一萬五千倍?？墒沁@種高氦的天然氣礦藏并不多，因為天然氣中的氦氣是鈾之類的放射性元素衰變的產(chǎn)物。只有在天然氣礦附近有鈾礦時，氦氣才能在天然氣中匯集。美國氦氣資源占50%以上，中國僅占0.2%。美國生產(chǎn)的氦氣要占世界總產(chǎn)量的80%以上。2007年，美國將氦氣核定為戰(zhàn)略物資而限制粗氦產(chǎn)量，導致全球液氦價格由原來60～80元/每升，上漲到目前200元/每升以上。SummaryRONFUFMFDialysisEDPVGS分離原理篩分篩分篩分篩分篩分離子遷移溶解擴散篩分推動力壓差壓差壓差壓差濃差電位差壓差壓差工作壓力2-10MPa0.9-1.5MPa0.1-1.0MPa0.05-0.5MPa13.5MPa應用鹽、氨基酸、糖的濃縮，淡水制造水軟化、有機物和生物活性物質的除鹽和濃縮水軟化、有機物和生物活性物質的除鹽和濃縮菌體、細胞和病毒的分離、固液分離脫鹽、除變性劑脫鹽、氨基酸和有機酸分離有機溶劑與水的分離，共沸物的分離（如乙醇濃縮）多種氣體的分離，提濃工藝5.4membranefoulingDefinitionTheprocessthatresultsinadecreaseinperformanceofamembrane,causedbythedepositionofsuspendedordissolvedsolids

ontheexternalmembrane

surface,onthemembranepores,orwithinthemembranepores.(TheInternationalUnionofPureandAppliedChemistry)Contamination

ofmembranescausesahigherenergyuse,ahighercleaningfrequencyandashorterlifespanofthemembrane.Membranecontaminationisusuallycalledfouling.TypesofMembranefouling膜污染PorePlugging孔堵塞Adsorption吸附Concentrationpolarisation濃差極化GelLayerformation凝膠層形成FactorsaffectingfoulingFeedMembranetypeFlowConfigurationTransmembranepressureControllingFoulingBackflushingFeedmodificationMembranechoiceForcrossflowuselowTMP(Transmembranepressure.)CleaningAnillustrationoftheefficiencyofback-pulsinginremovingfoulingmaterialsfromthesurfaceofmicrofiltrationmembranes.DirectmicroscopicobservationsofMoresandDavisofcelluloseacetatemembranesfouledwitha0.1wt%yeastsuspension.Themembranewasbackflushedwithpermeatesolutionat3psiforvarioustimes.5.5membranemoduleshollowfibermembranemodule（中空纖維膜組件）tubularmembranemodule（管式膜組件）plateandframemodule（平板式膜組件）SpiralWoundmodule（卷式膜組件）ModuleTypeCharacteristicsFlatplateSpiralWoundShellandTubeHollowFibrePackagingdensity(m2/m3)ModerateModerateLowHighFluidmanagementGoodGoodHighpumpingcosts