Phase equilibrium in the system water‐hydrogen sulphide: Hydrate‐forming conditions

Abstract

Recently revealed problems with the fluid phase equilibria data for the system H, S-H,O as presented by Selleck et al. (1952) prompted this review of the hydrate-forming conditions. The smoothed tables of Selleck et al. (1952) along the three-phase loci are replaced with equations which are based on a critical review of all of the experimental data.Les problbmes soulevis ricemmenl h propos des donnees d'equilibre en phase liquide pour le systbme H,S-H,O telles qu'elles sont prisenties par Selleck et al. (1952) nous ont incites B examiner les conditions de formation des hydrates. Les tableaux lisses de Selleck et al. (1952) ainsi que les loci des trois phases sont remplaces par des Cquations basks sur un examen critique de toutes les donntes experimentales. ~

Phase equilibria in the system CO2-H2O I: New equilibrium relations at low temperatures

“…Not surprisingly, a topology nearly identical to that shown in Figure 3 has been proposed for at least one other clathrate-forming binary system, H 2 S-H 2 O (Carroll and Mather, 1991). Carroll and Mather (1991) employed the "Q" nomenclature for the quadruple points such that Q 1 ϭ G-L-H-W {SI}, Q 2 ϭ G-H-W-I {SL}, Q 3 ϭ S-G-L-H {WI}, and Q 4 ϭ S-G-H-I {LW} where S is solid H 2 S and L is H 2 S-rich liquid.…”

“…However, they did not analyze the relation between composition and topology as was done in Figure 4 and consequently did not propose an azeotrope. Nonetheless, the arrangement of univariant curves shown by Carroll and Mather (1991) around the {WI} point requires that the gas phase coexisting with hydrate and H 2 S-rich liquid is richer in H 2 O than the coexisting H 2 S-rich liquid, whereas the sulphide-rich liquid is richer in H 2 O than coexisting gas in the vicinity of {SI}. In another paper Carroll and Mather (1989) provided compositional data that indeed showed suphide-rich liquid to contain more H 2 O than coexisting sulphiderich gas along the L ϭ GϩW curve where it intersects point {SI}.…”

“…Carroll and Mather (1991) employed the "Q" nomenclature for the quadruple points such that Q 1 ϭ G-L-H-W {SI}, Q 2 ϭ G-H-W-I {SL}, Q 3 ϭ S-G-L-H {WI}, and Q 4 ϭ S-G-H-I {LW} where S is solid H 2 S and L is H 2 S-rich liquid. They showed precisely the same arrangement of univariant equilibria around {WI} and {LW} as shown in Figure 3-even terminating the LSG equilibrium at the H 2 S triple point.…”

Geological Hazards

“…(H 2 S), carbon dioxide (CO 2 ), ethane (C 2 H 6 ), and propane (C 3 H 8 ) are part of the hydrate-forming gas mixture (Carroll and Mather, 1991;Sloan, 2006;Kvenvolden, 1998). The presence of hydrogen sulfide (H 2 S) and carbon dioxide gases with methane make the hydrate phase equilibrium stable at higher temperatures and lower pressures.…”

Review of vapor-liquid equilibria of gas hydrate formers and phase equilibria of hydrates

“…As mentioned earlier, the most recent data on N 2 hydrates was measured by Mohammadi and Richon [264] using the isothermal pressure search method. Extensive work on H 2 S hydrates was performed by Selleck [301] and Carroll and Mather [302,303]. Most recent work on H 2 S hydrates is by Ward et al [235], who used the isochoric pressure search method and phase boundary decomposition (PBD) method to measure H 2 S hydrate phase equilibria data from about 273 K to 301 K. …”