A GENERALIZED QUARTIC EQUATION OF STATE

A generalized quartic equation of state has been developed for nonpola r and polar fluids. The quartic equation of state needs only four flui d properties to predict physical and thermodynamic properties over a w ide range of temperatures and pressures. These four properties are cri tical volume, critical temperature, acentric factor and dipole moment. The new equation of state models the repulsive forces between molecul es correctly, unlike the cubic equations of state. One of the four roo ts obtained by solving the equation of state is always negative, makin g it possible to identify the remaining three roots like the roots of a cubic equation. The quartic equation of state shows superior perform ance compared with the Peng-Robinson equation of state.