A new quartic equation of state

Abstract

A new quartic equation of state (EOS) is presented, which consists of the repulsive term of CCOR EOS and the attractive term of PT EOS, coupled with new parameters, the general forms of which are given for non-polar substances. The new EOS can be solved algebraically like a cubic EOS. Calculated vapor pressures, specific volumes and evaporation enthalpies are compared with experimental data and with that calculated by CCOR EOS and PT EOS for a variety of fluids. In low temperature region, the new quartic EOS produces more reliable results than commonly-used cubic EOS. One important character of the new EOS is that it is capable of calculating specific volume of solid and sublimation pressure. The vapor–liquid equilibria (VLE), including volume properties, of binary mixtures are also well presented by the new EOS with van der Waals one-fluids mixing rules containing one adjustable parameter.