Experimental measurement and phase behavior modeling of hydrogen sulfide-water binary system

Here, new vapor-liquid equilibrium data of H2S-H2O binary system are reported over the 298.16-338.34 K temperature range for pressures up to 3.962 MPa. The experimental method is based on a static analytic apparatus, taking advantage of two ROLSI pneumatic capillary samplers. An extensive literature review has been conducted on the mutual solubilities of H2S-H2O systems and H2S hydrate formation conditions. A critical evaluation of the literature data has been performed to identify any inconsistencies in the reported data. A thermodynamic model has been used to represent the experimental data. The Valderrama modification of the Patel-Teja equation of state combined with nondensity dependent mixing rules is selected to model the fluid phases. The hydrate phase is modeled by the solid solution theory of van der Waals and Platteeuw with previously reported Kihara potential parameters. The fugacity of ice is calculated by correcting the saturation fugacity of H2O at the same temperature using the Poynting correction. The new H2S solubility data generated in this work are used for tuning the binary interaction parameters between H2S and H2O. The new measured and predicted vapor-liquid equilibrium data, as well as model predictions for the hydrate dissociation conditions of H2S, are compared with the experimental data in the literature. The results are in good agreement, demonstrating the reliability of the technique and model presented in this work.