Separation Of Azeotropic Mixture Via Ionic Liquid Catalyzed Reactive Distillation And Ionic Liquid Extraction

Ionic liquids are green solvents, and they play more and more important rolesin chemical industry. The extraction process for the separation of methyl ethyl ketone+water azeotropic system with1-ethyl-3-methylimidazolium acetate as solvent andthe hydrolysis of methyl acetate+methanol azeotropic mixture via reactivedistillation with N-butylsulfonate Pyridinium trifluoromethanesulfonate as catalystwere studied.The liquid-liquid equilibrium of the ternary system of methyl ethyl ketone+water+1-ethyl-3-methylimidazolium acetate（[EMIM][Ac]） was measured, and theresults indicated that [EMIM][Ac] was an effective solvent for the separation ofmethyl ethyl ketone+water via liquid-liquid extraction. The liquid-liquid equilibriumdata were correlated by NRTL activity coefficient model and the binary interactionparameters were obtained. The correlation results agreed well with those ofexperimental. The liquid-liquid extraction process was simulated, and the effects oftheoretical plates number and solvent ratio(the ratio of the mole flow rate of solvent tofeed) on the extraction process were investigated. The optimal operation parameterswere obtained by the sensitivity analysis.The reaction kinetics data for the hydrolysis of methyl acetate catalyzed by ionicliquid N-butylsulfonate Pyridinium trifluoromethanesulfonate([BSMePy][OTf]) wasmeasured. Two different kinetic models, the ideal pseudo-homogeneous (IPH) modeland the non-ideal pseudo-homogeneous (NIPH) model, were proposed based on thereaction mechanism to correlate the reaction kinetic data. The NIPH model was ableto describe the reaction better. The recycle of ionic liquid catalyst was investigated aswell, and the catalytic activity of [BSMePy][OTf] was nearly unchanged after5recycles.The hydrolysis of azeotropic mixture of methyl acetate+methanol via reactivedistillation using [BSMePy][OTf] as catalyst was simulated. Three reactivedistillation processes were proposed and compared by simulation, and the optimalprocess was selected. The effects of water feeding position, methyl acetate-methanolfeeding position, side stream position, theoretical plates number, recycle flow rate ofdistillate, reflux ratio, liquid holdup, flow rate of water and side stream on the reactive distillation were investigated. The optimal parameters were obtained by sensitivityanalysis. The conversion of methyl acetate can reach99.34%, the purity of methanolwas0.9922and the purity of acetic acid was0.9921, if the reactive distillationoperated in the optimal condition.