Equilibrium solubility of H₂S and CO₂ and their mixtures in a mixed solvent

The solubility of hydrogen sulphide, carbon dioxide, and their mixtures has been measured at 40° and 100°C in a mixed solvent consisting of 20.9 wt% MDEA (methyldiethanolamine), 30.5 wt% sulfolane (tetrahydrothiophene‐1, 1‐dioxide), and 48.6 wt% water. The results have been compared with those for aqueous 2.0 mol/dm 3 MDEA and an analogous mixed solvent, containing AMP (2‐amino‐2‐methyl‐1‐propanol), which are available in the literature. These data were used to modify the solubility model of Deshmukh and Mather (1981) to account for the mixed solvent effects on the system thermodynamics. Results show that the model is useful as a first approximation in predicting acid gas solubilities; agreement with experiment was generally found to be within £15%.