FROM REDLICH-KWONG TO THE PRESENT

The application of several recent modifications of the Redlich-Kwong equation of state to the calculation of thermodynamic and physical properties is discussed. These equations have generally incorporated changes in both formulation and temperature-dependence of the attractive term in order to more accurately predict PVT, enthalpy, or phase equilibrium behavior. More recently, modifications to the repulsive term have been proposed to improve predictions at high densities. This paper discusses the strengths and weaknesses of these modifications and outlines the limitations of simultaneously predicting these properties with a single cubic equation of state.