Ternary liquid-liquid phase equilibria of {ionic liquid plus thiophene plus (octane/hexadecane)}

In this work we studied the applicability of two ionic liquids (ILs) for the separation of thiophene from octane, or hexadecane, as a model of the diesel stream. Experimental liquid-liquid phase equilibrium (LLE) data were obtained for four ternary systems {IL + thiophene + octane, or hexadecane} at T= 308.15 K and pressure p = 101 kPa. The ILs 1,3-dihydroxyimidazolium bis{(trifluoromethyl)sulfonyl} imide, [OHOHIM][NTf2] and 1-butyl-3-methylimidazolium trifluoromethanesulfonate, ([BMIM] [CF3SO3]), [BMIM][OTf] were used to assess the desulfurization process. [BMIM][OTf] showed better selectivity than [OHOHIM][NTf2] in the extraction of thiophene from both, octane and hexadecane. The distribution ratio in all systems is acceptable in comparison with currently published data for different ILs. Chromatography analysis showed that the IL was not present in the octane, or hexadecane layer. This simplifies the process separating the solvent from the hydrocarbon layer. The data obtained have been correlated with the non-random two liquid (NRTL) model. (C) 2019 Elsevier Ltd.