Vapor–Liquid Equilibrium of Toluene/Heptane and Benzene/Cyclohexane Systems with Biobased Cyrene: Experimental Data and Thermodynamic Modeling

Separation of hydrocarbon mixtures is essential for the efficient utilization of resources in the chemical industry. In this study, we investigated the vapor–liquid equilibrium (VLE) behavior of two binary systems, toluene + heptane and benzene + cyclohexane, and examined the application of the biobased solvent, Cyrene, as an extractant in the ternary systems. The vapor–liquid-phase equilibrium data were correlated by a nonrandom two-liquid (NRTL) model, and the results showed that the addition of Cyrene significantly increased the relative volatility of the two binary systems up to 3, and the deviation of all systems was less than 5%. Compared with conventional organic solvents such as SUL, DMSO, NMP, and DMF, Cyrene not only demonstrated good separation performance but also offered significant advantages in terms of environmental sustainability. The results suggest that Cyrene has great potential as a green alternative for sustainable hydrocarbon separation processes.