A New Three-Parameter Pseudo-Cubic Equation of State

A three-parameter pseudo-cubic equation of state is proposed. The pseudo-cubic equation of state is a sixth power polynomial equation in volume, which may be solved in a manner similar to conventional cubic equations. The proposed equation has a maximum of three positive roots. The proposed equation has successfully described the critical isotherms of argon, carbon dioxide, and water. The three adjustable equation-of-state parameters have been treated both as a function of temperature and as constants. Performance comparisons with other three parameter equations of state are given. The results of the comparisons indicate the proposed equation or state to be superior in a number of ways, especially in the prediction of liquid densities. The proposed equation of state has also been successfully applied to the correlation of high pressure vapor-liquid equilibria of cryogenic fluid mixtures.