11 COMPOSITION OF PRODUCTS YIELD FEED QUANTITY COMPOSITION OF FEED Definition of the separation problemCOMPOSITION OF PRODUCTSYIELDFEED QUANTITYCOMPOSITION OF FEEDPHASE EQUILIBRIA:(EXPERIMENT; CORRELATING)SEPARATION FACTORS
12 COUNTERCURRENT MULTISTAGE EXTRACTION Definition of TaskCOUNTERCURRENT MULTISTAGE EXTRACTIONDetermine:Number of theoretical stages(or number of transfer units).Height (Size) of a separation deviceSeparation performance (Mass Transfer)Capacity of a separation deviceThroughput -----> diameter
13 Maximum concentration in a countercurrent process Limiting Phase EquilibriumMaximum concentrationin acountercurrent process
23 McCabe-Thiele Analysis Design Methods For Number of Theoretical StagesMcCabe-Thiele AnalysisPonchon-Savarit in aJänecke-DiagramSimulation
24 CC-GE: Basic Equations Mass balances:Enthalpy balances:Equilibrium relations:Rate equations for mass transfer:
25 with:z = axial coordinate in the separation device;Li, Vi = flow of component i in the liquid and gaseousphase;L, V = total flow of liquid and gaseous phase;HV, HL = enthalpy of gaseous and liquid phase;kGi = mass transfer coefficient of component i, relatedto the gaseous phase;a = mass transfer area per volume of transferdevice;P = total pressure;Ki = equilibrium partition coefficient of component ibetween gaseous and liquid phase;Vi* = equilibrium concentration of component i in thegaseous phase.
33 Simulation of the separation Select method: nth or NTU Determine min. reflux, min. nth or NTUVary reflux-ratio;Calculate separation as function of nth or NTUCalculate nth or NTU as function of separationDetermine concentration profiles.
41 Solexol - Process with near critical propane IEC 41:280, 1949
42 Multistage cc separation of n3- FAEE Krukonis 1988
43 Multistage cc separation of n3- FAEE THEORYKrukonis 1988
44 Multistage cc separation of n3- FAEE THEORYKrukonis 1988
45 SOLVING A MULTICOMPONENT SEPARATION IN CC-GE Define the mixture: Summary and Design ProcedureSOLVING A MULTICOMPONENT SEPARATIONIN CC-GEDefine the mixture:components or pseudo-componentsDefine the separation:identify key components,purity and recovery rateDetermine separation performance:(as a function of reflux ratio):number of theoretical stages (n ) ornumber of transfer units (NTU)
46 Determine efficiency of mass transfer equipment: Summary and Design ProcedureDetermine efficiency of mass transfer equipment:tray efficiency, or HETP, or HTUDetermine limits for mass flowof countercurrent streams:maximum flow (entrainment, flooding)minimum flow (for effective mass transfer)Decide for a certain reflux ratioCalculate separation performancesize of a columnfor the chosen equipment and operating conditions