APPLICABILITY OF THE UNIFAC METHOD FOR PREDICTION OF BINARY AND TERNARY VAPOR-LIQUID-EQUILIBRIUM DATA IN SYSTEMS FORMED BY HYDROCARBONS AND ALCOHOLS

The problem of the prediction and correlation of vapour-liquid equilibria in binary and ternary systems has been discussed and the limitation in the applicability of the UNIFAC method for this purpose has been pointed out. The total pressure data for six ternary systems (cyclohexane-2-propanol-benzene, cyclohexane-ethanol-benzene, n-heptane-1-propanol-benzene, n-hexane-ethanol- benzene, cyclohexane-methanol-benzene, cyclohexane-ethanol-toluene) and eighteen corresponding binary mixtures (benzene-2-propanol, benzene-cyclohexane, cyclohexane-2-propanol, cyclohexane-ethanol, cyclohexane-benzene, ethanol-benzene, ethanol-benzene, n-hexane-benzene, n-hexane-ethanol, benzene-1-propanol, benzene-n-hexane, n-heptane-1-propanol, cyclohexane-methanol, benzene-cyclohexane, benzene-methanol, cyclohexane-ethanol, benzene-cyclohexane, benzene-ethanol) have been selected and correlated by means of the Redlich-Kister equation and compared with the results predicted by the UNIFAC method. The correlation and the prediction results have been fully discussed from the point of view of intermolecular interactions and some recommendations have been made on the use of the methods investigated for such calculations. © 1990.