Liquid−Liquid Equilibrium Data for 1-Butanol–Methylcyclohexane and Acetonitrile–Benzene Mixtures Using Multiple Deep Eutectic Solvents Based on Choline Chloride

Abstract

Choline chloride (ChCl)-based deep eutectic solvents (DESs) have been utilized as a green extracting agent for the efficient extraction of 1-butanol from methylcyclohexane + butanol combinations and acetonitrile from benzene + acetonitrile mixture at atmospheric pressure and 298.15 K. The prepared DESs were ChCl + urea (DES1; 1:2 molar ratio), ChCl + 1,2-propanediol (DES2; 1:3 molar ratio), ChCl + ethylene glycol (DES3; 1:2 molar ratio), and ChCl + glycerol (DES4; 1:2 molar ratio). The Hand and Othmer–Tobias equations were used to evaluate the tie-line compositions’ reliability. The extrication abilities of the examined DESs to separate methylcyclohexane +1-butanol and benzene + acetonitrile mixtures were compared to the NRTL model. The binary interaction parameters were established when the NRTL model corroborated the measured equilibrium data. The Gibbs topological analysis was utilized to validate consistency of the model parameters. The extraction equilibrium data showed that the selectivity parameter was higher than unity (S > 1) in all the evaluated systems. The distribution coefficient factor in systems containing ChCl–urea was higher than unity, indicating the need for smaller amounts of solvents to separate 1-butanol from methylcyclohexane, and the number of extraction steps was reduced. The distribution coefficient factor was less than unity in all systems, and more DESs were needed for optimal separation of acetonitrile from benzene.