Separation of Dimethyl Carbonate and Methanol by Deep Eutectic Solvents: Liquid–Liquid Equilibrium Measurements and Thermodynamic Modeling

To separate the mixture of dimethyl carbonate and methanol, two deep eutectic solvents (DESs), choline chloride with glycerol and ethylene glycol, with the molar ratio of 1:2 were prepared to separate dimethyl carbonate from the mixture by liquid–liquid extraction. The liquid–liquid equilibrium (LLE) data for the ternary systems of dimethyl carbonate + methanol + DESs were determined at temperature of 298.15 and 308.15 K under 101.3 KPa. The measured tie-line data were validated by the Bachman equation, and the correlation coefficients ( R 2 ) were all close to 1. Meanwhile, the distribution coefficient and selectivity were calculated from the experimental results. The LLE experimental data were correlated using the nonrandom two-liquid (NRTL) model, and the correlated results agree well with the LLE experimental data. Also, the parameters of the NRTL model were regressed.