EXTENSION OF A GENERALIZED QUARTIC EQUATION OF STATE TO PURE POLAR FLUIDS

A generalized four-parameter quartic equation of state (EOS) proposed by Shah and coworkers (1992, 1994) was extended to polar fluids. To us e the new generalized quartic EOS for polar fluids, only four characte ristic properties of the pure compound are required-critical temperatu re, critical volume, acentric factor, and dipole moment. For nonpolar fluids, the previous equation is recovered and its superior performanc e for nonpolar fluids is retained. A new set of coefficients for polar fluids for the EOS was determined from multiproperty regressions usin g literature data for various physical and thermodynamic experimental properties of 30 pure compounds. These regressed coefficients, which a re functions of the critical temperature, critical pressure, acentric factor, and the dipole moment of the fluid, were generalized. The accu racy of this equation of state is evaluated with the new set of regres sed coefficients to predict thermodynamic properties of pure polar com pounds, including vapor pressure, density residual enthalpy, enthalpy of vaporization, and second virial coefficient. The capability and acc uracy of this quartic equation of state are also compared with the wel l-known Peng-Robinson EOS.