A Promising Ionic Liquid [BMIM][FeCl4] for the Extractive Separation of Aromatic and Aliphatic Hydrocarbons

Abstract

Liquid–liquid equilibria (LLE) of the following ternary systems were measured at atmospheric pressure, that is, {cyclohexane + benzene + [BMIM][FeCl4]} at T = 298.15 K and 313.15 K, {n-hexane + benzene + [BMIM][FeCl4]}, {n-heptane + toluene + [BMIM][FeCl4]} at T = 298.15 K, and {cyclohexane + benzene + [BMIM]Cl} at T = 339.15 K. The extraction performance of ionic liquid (IL) [BMIM][FeCl4] for the aromatic hydrocarbons (benzene or toluene) from their aliphatic hydrocarbons (cyclohexane, n-heptane, or n-hexane) was analyzed and compared with some imidazolium-based ILs. The results indicate that the IL [BMIM][FeCl4] shows both higher extractive selectivity and distribution factor for the systems studied herein and thus is a promising solvent for the extractive separation of aromatic and aliphatic hydrocarbons. The LLE data were well-correlated by the nonrandom two-liquid (NRTL) model of nonelectrolyte solutions with the overall average absolute relative deviation (rmsd) being about 0.0188 in terms of the mo...