Measurement and correlation of the vapor-liquid equilibrium of cyclohexane plus ethanol containing ILs and the thermophysical properties of these ILs at 101.3 kPa

Some important topics and issues related to possible extractive distillation separation of cyclohexane + ethanol system using ionic liquids (ILs) are presented in this manuscript. Three ILs with acetate anion (methyl-trioctyl-ammonium acetate [N-1,N-8,N-8,N-8][Ac], 1-decyl-3-methyl-imidazolium acetate [DMIM][Ac] and 1-hexadecyl-3-methyl-imidazolium acetate [C16MIM][Ac]) were selected as entrainers. The vapor-liquid phase equilibrium (VLE) data for cyclohexane + ethanol + ILs system were determined at 101.3 kPa and correlated by Wilson and NRTL models. The separation effect of these ILs on the basis of the NRTL model follows this order: [N-1,N-8,N-8,N-8][Ac] > [DMIM][Ac] > [C16MIM][Ac]. The binary VLE data of the cyclohexane-ethanol mixture obtained by this device were compared with previously published data and tested by the Herington thermodynamic consistency test. Temperature dependence of some thermophysical properties (density, viscosity and heat capacity) of these ILs were obtained and correlated within the range of possible distillation operating temperatures. (c) 2020 Elsevier Ltd.