Liquid-liquid equilibrium data for ternary mixtures (water + isopropanol + 1-pentanol/1-hexanol/1-heptanol) at 298.15 K: Measurement, correlation and prediction

Abstract

To recover isopropanol from its aqueous solution, alkanols (1-pentanol, 1-hexanol and 1-heptanol) were selected as the solvents to separate water and isopropanol. Liquid-liquid equilibrium data for water + isopropanol + 1-pentanol/1-hexanol/1-heptanol ternary systems were measured at 298.15 K under 101.3 kPa. The mass conservation of the experimental data was checked, and the reliability of the tie-lie data were evaluated by the Bachman, Hand and Othmer-Tobias equations. The extraction performance of the three solvents was assessed through the separation factor and partition coefficient, and compared with those for other reported solvents {esters, ketones, ethers, alkanes (or alkenes), ionic liquids and deep eutectic solvents}, indicating that 1-heptanol has better extraction performance for isopropanol compared with other two solvents. The NRTL and UNIQUAC models were used to correlate the data to obtain regression parameters. The mixed surface analysis based on Gibbs energy topology verified that the binary interaction parameters are consistent with the measured data. Furthermore, the LLE binodal curve for the researched ternary systems were predicted through the UNIFAC and COSMO-UNIFAC models.