Ternary liquid–liquid equilibria of bis(trifluoromethylsulfonyl)-amide based ionic liquids + thiophene + n-heptane. The influence of cation structure

Ternary liquid–liquid equilibria for 3 systems containing ionic liquids (4-(2-methoxyethyl)-4-methylmorpholinium bis(trifluoromethylsulfonyl)-amide, 1-(2-methoxyethyl)-1-methylpiperidinium bis(trifluoromethylsulfonyl)-amide, 1-(2-methoxyethyl)-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)-amide) + thiophene + n-heptane have been determined at T = 298.15 K. All systems showed high solubility of thiophene in the ionic liquid and low solubility of n-heptane. The solute distribution coefficient and the selectivity were calculated for all systems. High selectivities were obtained. The experimental results have been correlated using NRTL model. The influence of cation structure on phase equilibria is discussed.

► Ternary liquid–liquid equilibria for 3 ionic liquids + thiophene + n-heptane systems.
► The influence of ionic liquid cation structure on phase diagrams is discussed.
► High selectivity for separation of n-heptane/thiophene is observed.