Abstract
A group contribution model is developed, based on the hole theory, for thermodynamic properties of pure liquids of normal alkanes, aromatics and their solutions, including heats of vaporization, pVT relations and activity coefficients. In the present model, the combinatorial factor is approximated by the Flory-Huggins expression, the free volume is expressed by a simplified Henderson''s approximation, and a lattice potential energy is made up of pair interaction contributions of segments. By using parameters determined with data reduction of pure liquids and their solutions, pure liquid properties over a wide reduced-temperature range from 0.3 to 0.8 and mixture properties such as activity coefficients are accurately predicted and correlated. Since an equation of state derived from the present new model satisfies the ideal gas limit at infinite volume, it is applied to estimate thermodynamic properties of gaseous phase.
