Liquid–Liquid Equilibrium Measurements and Correlation for Ternary Systems (Butyl Acetate + 1-Butanol + Ethylene Glycol/1,3-Propanediol/Ethanolamine) at 298.15 K

For separation of the azeotropic mixture butyl acetate and 1-butanol, ethylene glycol, 1,3-propanediol, and ethanolamine were chosen as the extractants. The phase equilibria for the ternary systems (butyl acetate + 1-butanol + ethylene glycol/1,3-propanediol/ethanolamine) were investigated, and the liquid–liquid equilibrium (LLE) data were determined at 298.15 K and 101.3 kPa. During the LLE measurement, the equilibrium was achieved when the prepared ternary mixture was stirred for 2 h and settled for 12 h. To evaluate the extraction capacity of the solvents, the distribution constant ( D ) and selectivity ( S ) were calculated. From the comparison of the values of D and S, ethanolamine is the best extractive solvent among the three solvents. In the meantime, the nonrandom two-liquid (NRTL) and the universal quasi-chemical (UNIQUAC) models were applied to correlate the LLE data for the systems. The values of the root mean square deviations between the experimental LLE data and calculated values were less than 0.01. Also, the binary interaction parameters of the NRTL and UNIQUAC models were optimized.