Prediction of azeotrope formation in binary mixtures with pure component properties and limiting activity coefficients

• Azeotrope formation in binary mixtures is predicted in this paper • Pure component properties & limiting activity coefficients used in the prediction • Method for estimating vaporization heat is used to calculate boiling temperature • MOSCED model is used to calculate the mixing heat • The prediction results of this paper is comparable to the literature method For a binary mixture without azeotrope, its boiling temperature at quasi-infinite dilution T b Q I D < T b,H (the higher boiling temperature of the two components), and T b Q I D > T b,L (the lower boiling temperature of the two components). For a binary mixture with minimum boiling azeotrope, T b Q I D < T b,L at the neighbourhood of the lower-boiling-temperature component. For a binary mixture with maximum boiling azeotrope, T b Q I D > T b,H at the neighbourhood of the higher-boiling-temperature component. The above phenomena are used as predicting criteria for azeotrope formation in this paper. The value of T b Q I D is calculated by inversely using an existing method proposed to estimate the vaporization heat of pure liquid at its normal boiling temperature. The vaporization heat of the binary mixture at quasi-infinite dilution is taken as the sum of the vaporization heats of the pure components and the mixing heat to form the mixture, where the mixing heat can be estimated with the MOSCED (modified separation of cohesive energy density) Model or other limiting activity coefficient models. The method proposed requires only pure component properties, T b , T c , P c and the MOSCED parameters. The method is illustrated with 311 mixtures, and about 89% of mixtures are predicted successfully.