Calculations of Phase Equilibria at High Pressure in the Critical Region

The Redlich‐Kwong equation of state was used to calculate vapour liquid equilibria of binary systems in which both components are in the vicinity of their critical points. The systems CO2‐H2S, n‐heptane‐C2H4, and benzene‐C2H6 were selected. Furthermore, an attempt was made to compute gas‐gas‐equilibria. Calculations on the systems NH3 ‐ N2, NH3 ‐Ar, and NH3 ‐ CH4 which exhibit gas‐gas‐equilibria of the second type provided a qualitative agreement with experiment. In the systems He ‐ CO2, He ‐ C2H4, and He ‐ Xe which form gas‐gas‐equilibria of the first type the calculations agree fairly well with experiment.