Prediction of limiting activity coefficients by a modified separation of cohesive energy density model and UNIFAC

A modified separation of cohesive energy density (MOSCED) model was developed to predict limiting activity coefficients (..gamma..infinity's) using only pure component parameters. For 3357 ..gamma..infinity's, an average error of 9.1% was achieved with very few errors greater than 30%. The data included activity coefficients of both protic and aprotic (but nonaqueous) systems over wide temperature ranges. The results compared very well with the predictions of the leading predictive technique in the literature, the UNIFAC solution of groups approach (average error 20.5%).