Vapor-liquid equilibrium and extractive distillation for ethanol-water-ionic liquids ternary system

Isobaric vapor-liquid equilibrium data for ethanol-water-+-ternary systems were measured at 101.32 kPa using modified Othmer still.The experimental results indicate that the vapor-liquid equilibrium curves of the ethanol-water-ionic liquid(IL) systems deviate from that of the IL-free system and the deviation increases with increasing amounts of IL.The ionic liquid shows a salt-out effect,which increases the relative volatility of ethanol to water,and even leads to an elimination of the azeotropic point.+-can be used as the solvent of ethanol-water system for extractive distillation.The small extractive distillation process test was carried out as well.The purity of ethanol at top of the tower reaches 99.5%,which can meet the requirement of industry.