Vapor-liquid equilibria of isopropyl acetate-acetic acid-water system

Isobaric vapor-liquid equilibrium (VLE) data for isopropyl acetate-acetic acid and isopropyl acetate-acetic acid-water systems were measured at 101.33 kPa by using an improved Rose equilibria cell. The fugacity coefficients of components in the vapor phase were calculated by Hayden-O'connell method. The binary interaction parameters used to determine the liquid phase activity coefficients and expressed by the UNIQUAC and NRTL models, were got by applying the nonlinear least square method. For acetic acid-water system, 8 groups of NRTL interaction parameters obtained by fitting the published VLE data were respectively used to predict the VLE data of the isopropyl acetate-acetic acid-water system. Among them only three groups' prediction results are satisfactory and their average absolute deviations in temperature are less than 1.23°C. From the prediction results, it can be concluded that VLE data of acetic acid-water system have great influence upon the prediction of the VLE data of ternary system involving acetic acid and water and should be strictly selected.