The modified leung-griffiths model for vapor-liquid equilibria: Application to polar fluid mixtures

The Leung—Griffiths model as modified by Moldover and Rainwater has proven successful for correlation of critical-region vapor-liquid equilibria (VLE) surfaces of many binary nonpolar fluid mixtures. In this work the model is applied to four binary mixtures of polar fluids: diethyl ether + n-butanol and methanol + n-butanol as measured by Kay and Donham and the refrigerant mixtures R13B1 + R114 and R22 + R114 as measured by Uematsu, Watanabe and co-workers. The model provides accurate correlations of the polar mixtures, although the number of required adjustable parameters is in some cases larger than that needed for a nonpolar mixture with an equivalent critical locus.