Vapour liquid equilibrium calculations for dilute aqueous solutions of CO 2 , H 2 S, NH 3 and NaOH to 300°C

Henry's law constants for aqueous CO 2 , H 2 S and NH 3 up to 300°C have been recalculated from literature vapour pressure, enthalpy and heat capacity data. The high vapour pressure of water above 150°C causes significant solute‐water interactions in the gas phase, which were calculated using the Peng‐Robinson cubic equation of state. The results were combined with selected ionization constant data to derive a vapour‐liquid equilibrium model for dilute solutions. The model reproduces experimental data for binary systems at solute molalities of up to 0.5 m at 100°C, 1.0 m above 250°C and ionic strengths below about 0.1 m.