Mixing rule containing regular-solution and residual excess free energy

Abstract

A mixing rule is indispensable to the prediction of high-pressure vapor-liquid equilibria by means of the cubic equation of state. This paper proposes a new mixing rule of the energy parameter consisting of terms for geometrical mean of pure energy parameters and the residual part of the excess free energy at infinite pressure. Also, by using the new mixing rule and the SRK equation, high-pressure vapor-liquid equilibria are correlated with good accuracy for 14 binary systems consisting of non-polar, polar, and associating substances. © 1987, The Society of Chemical Engineers, Japan. All rights reserved.