GENERAL CORRELATIONS FOR PURE-COMPONENT PARAMETERS OF 2-PARAMETER EQUATIONS-OF-STATE

Empirical correlations for the calculation of pure-component parameters of two-parameter equations-of-state (EOS) and the acentric factor, omega, are proposed. Data for nearly 400 fluids have been used to develop the correlations. The liquid molar volume of a fluid at 20-degrees-C, v(L20), and the normal boiling point, T(b), are the only input data needed, while the critical temperature, T(c), and the critical pressure, P(c), need not to be known. The accuracy of the method can be enhanced when correlations are used, which are specific for a group of compounds (e.g., alkanes, aromatic compounds, alcohols, compounds containing nitrogen, etc). Correlations for ten groups of compounds are given. The applicability of the correlations was tested for two well-known EOS with a van der Waals repulsive term (Peng-Robinson and Redlich-Kwong-Soave) and for two Carnahan-Starling-type EOS (Dohrn-Prausnitz and Mulia-Yesavage). Results for vapor pressures and liquid densities, as well as an example for calculated phase equilibria are given.