Correlation of vapor−liquid equilibria of mixtures containing polar molecules by regular solution model with exponent−Type mixing rule

An extended regular solution model, in which an exponent.type mixing rule is introduced to the interaction term and a composition.dependent interaction parameter between unlike molecules is adopted, has successfully been applied to correlate vapor.liquid equilibria (VLE) of mixtures containing polar molecules. It is found that the exponent parameter is effective to represent VLE of polar systems such as ethanol + hydrocarbon binary systems. However, it is noted that the activity coefficient equations derived from the regular solution model become inadequate in the infinite dilution condition according to the exponent parameter. The behavior of activity coefficients in the extremely dilute region is discussed.

regular solution model

exponent−type mixing rule

vapor−liquid equilibrium

activity coefficient

infinite dilution condition