大学课件-化工原理下册-萃取小结english.ppt

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1、LIQUID-LIQUIDEXTRACTION（briefsummary）1unitoperation-toseparatecomponentsinaliquidmixture2differenceinsolubility3solventisaddedtochangesolubility4StepsInvolvedInExtractionsolute:Aoriginalsolvent:Bsolvent:SB,SimmiscibleS,A(Extract)B,A(Raffinate)B,SpartiallymiscibleS,A(B)(Extra

2、ct)B,A(S)(Raffinate)RemovalandrecoveryofsolventfromeachphaseExtract→ExtractliquidE′y′（A+（S、B））Raffinate→RaffinateliquidR′x′(B+（A、S））afterextractionprocesssupercritical-liquidassolvent(lastdecade)Liquid-likedensityGas-likediffusivityexhibitenhancedsolvatingGas-likeviscositypowe

3、rNon-toxicEnvironmentallyacceptableCO2isveryattractivealternativeABREMMisadditionpointSEisdifferencepointthelevellawright-angledisoscelestriangulardiagramABSR0E0MR1E1R2E2EnRnKsolubilitycurve3)conjugatephases1）solubilitycurve2）tieline4)plaitpointAuxiliarycurvedistributioncurvea

4、nddistributioncoefficientabscissa：SoluteconcentrationxAinRaffinatecoordinate：SoluteconcentrationyAinExtractdistributioncoefficientdistributioncoefficientfororiginalsolventCalculationofL-LExtractionNumberofstages:NEfficiency:ABSFMERSingle-stageExtractionwithPartiallyMiscibleS

5、olventABR'REFMSextractliquidandraffinateliquidABSFMERE'R'BFSE1R1R2E2Aamountofsolventy'AmaxABSy'AmaxERFMyA'MultipleContactco-currentflowsheetcounter-currentflowsheetco-currentflowsheetABSFM1R1E1M2R2E2M3R3E3R'3counter-currentflowsheet1）massbalanceE1、RNnotconjugatephasesDummyflow

6、D：right→leftAFMRNR'NE1DBS2）massbalanceovereverystage3）graphicmethodEquilibriumrelation：Ei,RiOperatingrelation：Ei+1,RiAFMRNR'NE1DR1E2FSRNE1DFSMRNE1→R1E2……ABFDSMR4RN'RNR3R2R1E1E2E3E4→→xn≤xNN=nE1、D→R1(inEquilibrium)D→→→E2(Operatingrelation)F,S,Rn→图8-31在直角坐标中图解下场论基数NABFRn'RnE1y

7、i+1xiM12iDS(a)xfxiyi+1y1xn操作线y分配曲线x123456iCi(b)0distributioncurveS/F，D,D=F-E1D-leftoftriangulardiagram，DummyflowDfromlefttoright(S/F)affectseparatingoperation(S/F)additionpointManddifferencepointDNS/F（S/F）minD=DminNS/Fy1slopeofoperatinglineDminRNF、DminE1FE1RNE

8、1,FSMMB,ScompletelyimmisciblemixtureS、Bareconstoverextractio