Liquid-liquid equilibrium determination and thermodynamics modeling for extraction of isopropanol from its aqueous solution

Abstract

To separate isopropanol from its aqueous solution, isobutyl acetate, butyl acetate and butyl propionate were adopted as the extractive solvents, and the liquid-liquid equilibrium (LLE) data for the ternary systems (isobutyl acetate / butyl acetate / butyl propionate) + isopropanol + water were determined at 298.15 K and 308.15 K under atmospheric pressure. The experimental LLE data were correlated by the NRTL and UNIQUAC models, and the values of the root mean square deviations (RMSD) were less than 1%. And the binary interaction parameters of the NRTL and UNIQUAC models were optimized. Meantime, the distribution coefficient and selectivity were calculated to evaluate the extraction capacity of the solvents. As a result, butyl propionate is a desirable extractive solvent compared with the other two solvents.