文摘
The removal and recycling of acetic acid from aqueous solutions is important for environmental protection and resource utilization. In this work, ionic liquid (IL) 1-ethyl-3-methylimidazolium diethylphosphate ([EMIM][DEP]) as an entrainer for the extractive distillation of the system water + acetic acid was investigated. Isobaric vapor鈥搇iquid equilibrium (VLE) data of the systems acetic acid + water, water + [EMIM][DEP], acetic acid + [EMIM][DEP], and water + acetic acid + [EMIM][DEP] have been measured at 101.32 kPa by using an improved Rose鈥揥illiams equilibrium still. The addition of [EMIM][DEP] showed a remarkable entrainer performance for the separation of acetic acid from its aqueous solution. The boiling point difference of the water + acetic acid system increased from 17.88 K (0 wt % IL) to 42.41 K (about 50 wt % IL), and the relative volatility (x1鈥?/sup> = 0.9) increased from 1.60 (0 wt % IL) to 5.28 (about 50 wt % IL). On the basis of the chemical theory and the Hayden鈥揙鈥機onnell (HOC) method, the parameters of the NRTL model for the binary systems were obtained, and the predicted values of the ternary systems of water + acetic acid + [EMIM][DEP] fitted the experimental VLE data well.