Separation of ethyl acetate and 2-propanol azeotropic mixture using ionic liquids as entrainers

Ionic liquids (ILs) as entrainers for the separation of ethyl acetate and 2-propanol azeotropic mixture were proposed in this work. Through the isobaric vapor-liquid equilibrium (VLE) experiments, we found that the three investigated ILs, namely 1-butyl-3-methylimidazolium acetate ([BMIM][Ac]), 1-butyl-3-methylimidazolium bromide ([BMIM][Br]), and 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]), could significantly enhance the separation factor of ethyl acetate and 2-propanol, and eliminate the azeotropic point. [BMIM][Ac] produced the most notable salting-out effect on ethyl acetate and 2-propanol among the three investigated ILs. Moreover, the experimental data were well correlated with the non-random two liquid (NRTL) model. Finally, σ-Profiles of solvents and ILs were used to explain the different separate abilities of the three investigated ILs.