Phase Behavior of Ternary Mixtures {Aliphatic Hydrocarbon + Aromatic Hydrocarbon + Deep Eutectic Solvent}: A Step Forward toward "greener" Extraction Process

The separation of aromatic and aliphatic hydrocarbons is a challenging process in the petrochemical industry. At present time, liquid-liquid extraction using volatile organic compounds (VOCs) has been widely practiced in the industry. Nevertheless, in the line with "green" technology, the use of VOCs have to be reduced as it cause pollution to environment. Recently, deep eutectic solvent (DES) have been viewed as alternative "green" solvent when compare to VOCs. Aimed at proposing "greener" solvent for liquid-liquid extraction of aromatic compounds from aliphatic hydrocarbon, in this work,novel ternary phase diagram composed of {hexane (1) + aromatic compounds such as benzene, toluene, or pyridine (2) + DES (3)} were determined at 298.15 K and at atmospheric pressure. The studied DES was prepared straightforwardly from choline chloride and glucose, and was displayed liquid form at room temperature. The phase equilibrium involving the studied DES were analyzed in term of the selectivity and solute distribution ratio and were compared with sulfolane, an organic solvent that currently used in industry as the benchmarked. Even though the studied systems showed lower distribution ratio when compare to sulfolane, the former systems displayed higher selectivity indicating the potential use of DES as potential solvent for the separation of aromatic from aliphatic hydrocarbons.