Deep eutectic solvents (DESs) are promising alternative for ionic liquids due to their low cost and sustainability. Considerable attention is paid on the ability of DES to replace ionic liquids in the separation of organic liquid mixtures via extraction. In this sense, it is important to determine the physicochemical
parameters of liquid-liquid equilibrium for the industrially significant mixtures and deep eutectic solvents. In the present work a mixture of n-octane, toluene and DES based on choline chloride and malonic acid was studied at 293.15, 313.15 K and atmospheric pressure. Tie-lines were obtained and ability of deep eutectic solvents to separate aliphatic-aromatic mixture was analyzed. Experimental liquid-liquid equilibrium data were fit with the NRTL model, and interaction parameters of components were obtained and discussed.