Collect. Czech. Chem. Commun. 1981, 46, 1541-1548

Comparison of different methods for estimating activity coefficients in binary mixtures of hydrocarbons

Vladimír Dohnal

Department of Physical Chemistry, Prague Institute of Chemical Technology, 166 28 Prague 6


The accuracy and reliability of a number of different methods for predicting activity coefficients in binary solutions of hydrocarbons was tested. Various modifications of the regular solution model and of the one-parameter Wilson equation and various group-contribution methods were applied to a set of 53 binary mixtures of hydrocarbons of different types. The agreement of the calculated and experimental dependence of activity coefficients on composition was considered. On using the best methods requiring the knowledge of pure component properties only, it is necessary to expect on the average an error of 7% in the value of activity coefficient. When using the group-contribution methods, which employ condensed information on related systems for the prediction, the mean error in the activity coefficient estimation lies about 4%.