CALCULATION OF VAPOR-LIQUID EQUILIBRIUM DATA FROM EXCESS THERMODYNAMIC PROPERTIES

Starting from isothermal excess enthalpy data (two or more than two sets) and isothermal vapo pressuredata (one set),and based on the principle of corresponding states of solutions,a complete computationprocedure of vapor-liquid equilibrium data is proposed:(1)Calculation of excess enthalpy ~E,based on the principle of corresponding states of solutions;(2) Calculation of Gibbs free energy ~E or its Q function;(3)Calculation of bubble point;(4)Calculation of vapor-liquid equilibrium data.The computation results for benzene-cyclohexane,benzene-n-hexane,benzene-n-heptane,benzene-n-octane,carbon tetrachloride-benzene,carbon tetrachloride-cyclohexane and carbon tetrachloride-n-heptane,compared with the corresponding vapor-liquid equilibrium experimental data are quite satisfactory.Theproposed computation procedure is appropriate to non-polar and slightly polar binary systems under rela-tively low pressures.