Liquid–Liquid Equilibrium Data for Cyclohexane–Ethanol–Solvent Ternary Systems and Their Correlation with the Nonrandom Two-Liquid Model

Liquid–liquid equilibrium data for a cyclohexane–ethanol–solvent ternary system were obtained at 303.15 K and 100.3 kPa using 1,4-butanediol, dimethyl sulfoxide, or N,N-dimethylformamide as the extractant. Extraction abilities of these solvents in the separation of ethanol from a mixture containing cyclohexane were determined in terms of the distribution coefficient and the separation factor derived from experimental values. The extraction ability of 1,4-butanediol was higher than those of the other two extractants for the separation of ethanol from cyclohexane. Moreover, the experimental data were fitted with the nonrandom two-liquid model, and the binary energy parameters were calculated accordingly. The divergence between the measured tie-line data and the calculated results was determined based on the root-mean-square deviation (RMSD). The highest value of RMSD was 0.98%, suggesting that the model is suitable for correlating the experimental values for the cyclohexane–ethanol–solvent ternary systems.