Modeling vapor-liquid phase equilibria of hydrogen sulfide and water system using a cubic EOS-GEX model

Abstract Vapor-liquid phase equilibria of the H 2 S H 2 O mixture were correlated by use of a cubic EOS-G EX over temperature and pressure range of 0.1–30 MPa and 278–627K. Average absolute deviations (AAD%) between the modeling results and the experimental data taken from literature for both the H 2 S-rich and the aqueous phases were found less than 5%. The new sets of EOS-G EX model parameters for H 2 S H 2 O mixture were evaluated from the experimental data over the above-mentioned temperature and pressure range. The proposed model was compared with the three previous published models and we discussed the advantages and the disadvantages for each of them. This study demonstrated that the advantages of the cubic EOS-G EX model in calculating phase equilibria of H 2 S H 2 O mixture over currently available models, especially at high pressures. The hydrate equilibrium, the salt effect, and the chemical reactions in the aqueous phase were not considered during phase equilibrium calculation in this study.