Cubic crossover equation of state

In this paper we develop a cubic crossover equation of state for pure fluids which incorporates the scaling laws asymptotically close to the critical point and is transformed into the original classical cubic equation of state far away from the critical point. We use the modified Patel–Teja (PT) cubic equation of state as a starting point. A comparison is made with experimental data for pure CO2, water, and refrigerants R32 and R125 in the one- and two-phase regions. We show that the crossover Patel–Teja equation of state yields a much better representation of the thermodynamic properties of pure fluids, especially in the critical region and for vapor–liquid equilibrium, than the original PT equation of state.