A NEW PREDICTIVE QUASI-LATTICE EQUATION OF STATE FOR HIGH-PRESSURE PHASE-EQUILIBRIA OF PURE FLUIDS AND MIXTURES

The recent success of analytical quasi-lattice equation of state (EOS) description of r-mer fluids by the present authors leads us to extend the EOS as a group contribution. With a size parameter for each group and an interaction energy parameter between groups, EOS parameters fo r pure fluids were calculated. Predicted high-pressure phase equilibri um properties of pure alkanes, cycloalkanes, aromatics, carbon dioxide and their mixtures showed good agreements with experimental data. Esp ecially, the present approach predicts phase equilibria of mixtures wi thout employing any type of adjustable binary interaction parameter, A s a result, high-pressure phase equilibrium behaviors of both pure flu ids and mixtures can readily be predicted solely from information on f unctional group interactions.