Experimental and Theoretical Study of the Phase Equilibria in Ternary Aqueous Mixtures of 1,4-Butanediol with Alcohols at 298.2 K

Abstract

Ternary liquid−liquid equilibrium (LLE) data for the mixtures of water + 1,4-butanediol + organic solvent (cyclohexanol, 2-ethyl-1-hexanol, and 1-decanol) were determined at 298.2 K and atmospheric pressure. These three ternary systems exhibit type-1 behavior of LLE. The immiscibility region was found to be larger for the branched aliphatic alcohol, 2-ethyl-1-hexanol. The experimental ternary LLE data were correlated using the UNIQUAC and NRTL models, and the binary interaction parameters were obtained. The reliability of the experimental tie-line data was tested through the Othmer−Tobias and Bachman correlation equations. Distribution coefficients and separation factors were calculated to evaluate the extracting capability of the solvents. The LLE results show that 2-ethyl-1-hexanol may be considered to be a reliable organic solvent for the extraction of 1,4-butanediol from aqueous solutions.