Equilibrium Data of Gas Hydrates containing Methane, Propane, and Hydrogen Sulfide

Abstract

Phase equilibria data on mixed hydrogen sulfide hydrates reported in the literature are very limited, especially for sII hydrate forming mixtures with H2S. In this study, six binary CH4 + H2S hydrate phase equilibria measurement results are reported in the temperature range from T = (283.31 to 293.22) K and pressure range from p = (2.00 to 6.8) MPa. Ten ternary CH4 + C3H8 + H2S sII hydrate phase equilibria measurement results are reported in the temperature range from T = (286.22 to 304.80) K and pressure range from p = (1.36 to 5.48) MPa. Experimental data were measured using the isochoric pressure search (IPS) method, which has been well established as a method for obtaining accurate hydrate phase equilibria data. Experimental data were compared to several hydrate phase equilibria prediction programs to assess their accuracy. For most models, predictions of the ternary sII hydrate system resulted in average absolute deviations in temperature of greater than 1 K.