Liquid–Liquid Equilibrium Measurements for the Ternary System of Water/2,3-Butanediol/4-Methyl-2-pentanol at Various Temperatures

Liquid–liquid equilibrium (LLE) of a ternary mixture of water, 2,3-butanediol, and 4-methyl-2-pentanol has been measured at three different temperatures (298.2, 308.2, and 318.2 K) under atmospheric pressure. The experimentally measured solubility and tie-line data for the two-phase system were used to construct a ternary phase diagram at each temperature. With the experimental data, the distribution coefficients and separation factors were also calculated and Othmer–Tobias and Hand plots were used to verify the consistency of the measured data. The universal quasichemical (UNIQUAC) and nonrandom-two liquid (NRTL) models were used for the LLE, and the root-mean-square deviation values between the calculated and experimental data were less than 1.21% by the UNIQUAC model and less than 1.96% by the NRTL model, indicating that both model calculations provide excellent agreement with the experimentally measured LLE data in the present study.