Liquid Extraction of Benzene from Its Mixtures Using 1-Ethyl-3-methylimidazolium Ethylsulfate as a Solvent

Abstract

In this work, the separation of benzene from cycloalkanes (cyclohexane, methylcyclohexane, and cyclooctane) was investigated by liquid extraction using the ionic liquid 1-ethyl-3-methylimidazolium ethylsulfate, [EMim][ESO4]. The liquid−liquid equilibrium (LLE) data were measured for the ternary systems formed by cycloalkane, benzene, and [EMim][ESO4] at 298.15 K and atmospheric pressure. The cloud point method was used to determine the solubility curve data, and the tie-line compositions were obtained by density measurements. The selectivity, the percent removal of aromatic, and the solute distribution ratio were calculated from the experimental LLE data. Selectivity and solute distribution ratio values were compared to those previously reported with other ionic liquids and sulfolane. Moreover, the influence of the size of the cycloalkane on the aromatic extraction was analyzed. The reliability of the experimental LLE data was tested using the Othmer−Tobias equation, and the NRTL and UNIQUAC models were used to correlate the experimental LLE data.