Liquid–Liquid Equilibria for Ternary Systems of Cyclohexane + Benzene + 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate/1-Butyl-2,3-dimethylimidazolium Tetrachloroferrate(III)

The development of finding a more efficient separation process for mixtures of cyclohexane and benzene is a challenging problem, and liquid–liquid equilibrium (LLE) is some of the basic data for the development. In this work, LLE for benzene + cyclohexane + [EMim][OTf]/[BMMim][FeCl₄] at T = 298.15, 308.15, 318.15 K and 101.3 kPa was experimentally measured, and thermodynamic consistency of the experimental data was tested by the Othmer-Tobias equation and the Hand equation. The experimental LLE data were correlated with the NRTL model, and the correlation results agreed well with the experimental data. The LLE data demonstrated that [EMim][OTf] exhibited high selectivity but showed a low distribution coefficient, and it is a good candidate for the separation of cyclohexane and benzene by pervaporation using a supported ionic liquid membrane. [BMMim][FeCl₄] has a high distribution coefficient but relatively low selectivity and is a potential solvent for the separation of cyclohexane and benzene by extraction.