Correlation and prediction of vle in ternary systems formed by hydrocarbons and alcohols

Abstract

The problem of the prediction and correlation of vapour-liquid equilibria (VLE) in ternary systems has been discussed and the limited applicability of the known methods for this purpose pointed out. A comparison of the efficiency of the various methods for ternary systems of different classes of mixtures has been undertaken. As a part of this work, total pressure data for 6 ternary mixtures (cyclohexane-ethanol-toluene, cyclohexane-ethanol-benzene, n-hexane-ethanol-benzene, cyclohexane-2-propanol-benzene, n-hexane-1-propanol-benzene, cyclohexane-methanol-benzene) and 18 appropriate binary mixtures (cyclohexane-ethanol, cyclohexane-toluene, ethanol-toluene, cyclohexane-ethanol, benzene-cyclohexane, benzene-ethanol, ethanol-benzene, n-hexane-benzene, n-hexane-ethanol, benzene-2-propanol, benzene-cyclohexane, cyclohexane-2-propanol, benzene-1-propanol, benzene- n-hexane, n-hexane-1-propanol, cyclohexane-methanol, benzene-cyclohexane, benzene-methanol) were selected and correlated by means of the NRTL, UNIQUAC, Wilson and NRTLMK equations. The ternary VLE data were then predicted using the binary parameters of the equations calculated from appropriate binary VLE data. The correlation and prediction results are fully discussed from the point of view of intermolecular interactions, and a number of recommendations on the use of the equations investigated for such calculations are made.