VAPOR-LIQUID AND LIQUID-LIQUID EQUILIBRIA IN BINARY AQUEOUS SYSTEMS

Vapor-liquid equilibrium (VLE) data are reported in the miscible region for mixtures of 2-pentanol/water at 70, 80, and 90 degree C and for 2-butanone/water at 60 and 70 degree C. Mutual solubility data (LLE) were obtained from the literature. For these two binaries, VLE and LLE data were correlated with several models for the excess Gibbs energy. None of the currently popular models is able to represent both VLE and LLE using only two or three adjustable parameters. For simultaneous representation, a slightly modified Van Laar equation appears to be useful but, in general, this modification requires four binary parameters. This work is pertinent to biotechnology.