Effect of the ionic liquids on extraction of aromatic and sulfur compounds from the model petrochemical stream

Suitability of a imidazolium ionic liquids (ILs) as solvents in dearomatization and desulfurization in the ternary systems and in a model multicomponent systems has been analyzed. With this aim, ternary liquid-liquid phase equilibrium data (LLE) have been obtained for ternary mixtures of {IL + benzene, or toluene, or thiophene, or 2-butanethiol + hexane}, or {IL + benzene + 2-methylpentane} at T = 298.15 K and ambient pressure, as well as for multicomponent systems –model petrochemical stream {IL + model stream (benzene, toluene, thiophene, 2-butanethiol) + hexane} at T = 303.15 K and ambient pres- sure. Two ILs have been studied: 1-ethyl-3-methylimidazolium thiocyanate, [EMIM][SCN] and 1-ethyl- 3-methylimidazolium dicyanamide, [EMIM][DCA]. The values of solute distribution ratio and selectivity have been evaluated. It has been shown that ILs investigated in this work are able to extract sulfur com- pounds in preference to benzene and toluene. The solute distribution ratios for both ILs are similar. The selectivity of the aromatic and sulfur compounds are higher for [EMIM][SCN]. The best distribution ratio ( > 1.98) and selectivity ( > 242) was observed for thiophene extracted from the model stream 1:1.