Vapor–Liquid Equilibrium Experiment for Butanone and Ethyl Acetate at 101.3 kPa

The formation of azeotrope brings severe challenges to the separation of butanone and ethyl acetate, two important chemical raw materials. In this article, two ionic liquids, 1-hexyl-3-methylimidazolium bis[(trifluoromethyl) sulfonyl] {[HMIM][NTf2]} and 1-ethyl-3-methylimidazolium bis[(trifluoromethyl) sulfonyl] {[EMIM][NTf2]}, and ethylene glycol (EG) were selected as entrainers to separate butanone and ethyl acetate. Vapor–liquid equilibrium data of butanone–ethyl acetate–[EMIM][NTf2], butanone–ethyl acetate–[HMIM][NTf2], and butanone–ethyl acetate–EG were measured at atmospheric pressure. The results show that the three extractants can effectively break the azeotrope of butanone–ethyl acetate, and the significant salt effect makes [EMIM][NTf2] and [HMIM][NTf2] show better separation ability than EG. Then, a non-random two liquid (NRTL) thermodynamic model was further used to fit the experimental data, and the average relative deviation was only 0.033, indicating that the NRTL model can well describe the influence of these three entrainers on the phase equilibrium behavior of butanone–ethyl acetate.