A new cubic equation of state for simple fluids: pure and mixture

A two-parameter cubic equation of state is developed. Both parameters are t aken temperature dependent. Methods are also suggested to calculate the att raction parameter and the co-volume parameter of this new equation of state . For calculating the thermodynamic properties of a pure compound, this equ ation of state requires the critical temperature, the critical pressure and the Pitzer's acentric factor of the component. Using this equation of stat e, the vapor pressure of pure compounds, especially near the critical point , and the bubble point pressure of binary mixtures are calculated accuratel y. The saturated liquid density of pure compounds and binary mixtures are a lso calculated quite accurately. The average of absolute deviations of the predicted vapor pressure, vapor volume and saturated liquid density of pure compounds are 1.18, 1.77 and 2.42%, respectively. Comparisons with other c ubic equations of state for predicting some thermodynamic properties includ ing second virial coefficients and thermal properties are given. Moreover, the capability of this equation of state for predicting the molar heat capa city of gases at constant pressure and the sound velocity in gases are also illustrated. (C) 2001 Elsevier Science B.V. All rights reserved.