Liquid–Liquid Equilibrium Measurement and Correlation for the Ternary Systems (Dimethyl Succinate + 1,4-Butanediol)/(Dimethyl Glutarate + 1,5-Pentanediol)/(Dimethyl Adipate + 1,6-Hexanediol) + Water at Different Temperatures

Liquid–liquid equilibria (LLE) data for esters + diols + water ternary systems were measured at 101.3 kPa at four different temperatures, namely, 293.15, 303.15, 313.15, and 323.15 K. The Othmer–Tobias equation and the Hand equation were applied to examine the reliability of the LLE data in which both regression coefficients were higher than 0.98. The calculated distribution coefficients and separation factors were larger than 1, which means that it is feasible to extract the diols from the corresponding ester with water. In addition, NRTL and UNIQUAC models were applied to correlate the experimental data, and the binary interaction parameters were obtained. The calculated root-mean-square deviation values show that both models are in good agreement with the experimental data.