Separation of Alkylbenzenes from n-Heptane Using Binary Mixtures of Ionic Solvents

Abstract

A study of liquid–liquid extraction of alkylbenzenes (propylbenzene, butylbenzene, or p-xylene) from n-heptane using ionic solvent binary mixture of 1-octyl-3-methylimidazolium hexafluorophosphate [C8C1im][PF6] and 1-ethyl-3-methylimidazolium methylsulfate [C2C1im][CH3SO4] is conducted at 313.2 K and a pressure of 101.3 kPa. The distribution ratio and selectivity for systems under study were calculated and compared to systems including other solvents such as sulfolane and other ionic liquids. The use of the present binary mixture of ILs provided a higher mole-based distribution ratio than the use of sulfolane, a pure IL, and a mixture of other ILs. On the other hand, the use of [C8C1im][PF6] and [C2C1im][CH3SO4] mixture contributed to a mass-based distribution ratio comparable to that of sulfolane and a higher distribution ratio than the others involving ILs and led to a higher selectivity than all the other solvents including sulfolane. Hence the extractive properties of [C8C1im][PF6] and [C2C1im][CH3SO4...