Determination and correlation of (liquid + liquid) equilibria of ternary and quaternary systems with octane, decane, benzene and [BMpyr][DCA] at T = 298.15 K and atmospheric pressure

• The ionic liquid BMpyrDCA was studied as solvents to extract aromatics from alkanes.
• (Liquid + liquid) equilibrium data were measured at T = 298.15 K for quaternary system and ternary systems.
• Selectivity and solute distribution ratio were calculated and compared.
• The comparison of results obtained on LLE data of ternary and quaternary systems was analyzed.
• Experimental data were satisfactorily correlated using NRTL model.

The suitability of the ionic liquid 1-butyl-1-methylpyrrolidinium dicyanamide, [BMpyr][DCA], as extraction solvent of benzene from its mixtures with octane and decane has been analyzed. (Liquid + liquid) equilibrium (LLE) data for the quaternary system {octane (1) + decane (2) + benzene (3) + [BMpyr][DCA] (4)} and for the ternary systems {octane (1) + benzene (2) + [BMpyr][DCA] (3)} and {decane (1) + benzene (2) + [BMpyr][DCA] (3)} were determined at T = 298.15 K and atmospheric pressure. Solute distribution ratios and selectivities were calculated from the experimental LLE data in order to evaluate the capability of [BMpyr][DCA] as extraction solvent. Finally, experimental results for the ternary and quaternary systems were correlated using the Non-Random Two-Liquid (NRTL) thermodynamic model.