CORRELATION OF HEATS OF MIXING OF LIQUID-MIXTURES BY THE NRTL MODEL

Using data for heats of mixing h(E), the temperature-dependent paramet ers of the NRTL model have been estimated for 55 systems of binary liq uid mixtures. In order to test the model thoroughly, systems of variou s types, including associating and partially miscible systems that hav e data for h(E) at more than one different isotherm, are considered. T he temperature dependence for the parameters of the model is assumed t o be linear. The physical meanings and non-uniqueness of the parameter s are discussed. Later these parameters are employed to predict the he ats of mixing, partial molar heats of mixing and activity coefficients at infinite dilution. In previous studies, the same properties were p redicted by assuming a non-linear temperature dependence for the param eters of the NRTL model. Hence the performance of the model is tested by comparing the predictions with experimental values when the linear and non-linear temperature dependences of the parameters are introduce d into the model.