Structures and Energetics of Elemental Sulfur in Hydrogen Sulfide

Roles of Carbon Dioxide and Methane in the Dissolution of Elemental Sulfur in Natural Gas

“…As shown in Figure b, the solubility also increases with the temperature at a given pressure. At P = 30 MPa, for example, the solubility increases from 2.31 mmol/mol at 353.2 K to 2.61 mmol/mol at 393.2 K. Previous DFT calculations revealed that the formation of the S 8 –H 2 S interaction is an exothermic process with a rather small and negative enthalpy change . The solubility increase under a high temperature cannot be interpreted by its negative enthalpy change if the dissolution is considered as the chemical process.…”

“…At P = 30 MPa, for example, the solubility increases from 2.31 mmol/mol at 353.2 K to 2.61 mmol/mol at 393.2 K. Previous DFT calculations revealed that the formation of the S 8 −H 2 S interaction is an exothermic process with a rather small and negative enthalpy change. 59 The solubility increase under a high temperature cannot be interpreted by its negative enthalpy change if the dissolution is considered as the chemical process. Instead, the interaction between S 8 and H 2 S is a typical physical process, as indicated by their rather weak interaction energy (less than 3.0 kcal/ mol 59 ).…”

“…59 The solubility increase under a high temperature cannot be interpreted by its negative enthalpy change if the dissolution is considered as the chemical process. Instead, the interaction between S 8 and H 2 S is a typical physical process, as indicated by their rather weak interaction energy (less than 3.0 kcal/ mol 59 ). For a physical process, the molecules have high kinetic energy under a high temperature, favoring the mixing of molecules and the dissolution of S 8 in H 2 S. One can see that the solubility variations within the studied pressure range are more remarkable than those within the studied temperature range, which indicates that the pressure change has a dominant influence on the sulfur solubility in the gas production process.…”

Molecular mechanism of elemental sulfur dissolution in H2S under stratal conditions

“…Moreover, the in situ characterization of H 2 S N species in high-sulfur gas formation remains challenging. Polysuldes were not detected when the experimental temperature was below 373 K, 9 but detected under 393-523 K. 11 In a computational study, He et al 12 reported that in the ground-state S N -H 2 S complexes, the interaction between S N (N = 2, 4, 6 and 8) and H 2 S is as weak as a typical physical interaction, but the effect of temperature was not considered. Intermolecular physical interaction was assumed in some recent molecular simulations [13][14][15][16] in which the force elds describing only the non-covalent interactions were used.…”

DFT Model of Elemental Sulfur in Sulfolane Solutions

“…There is a lot of work devoted to the structure of various molecular forms of sulfur − as well as the conditions under which they can be isolated ,− and studied using X-ray, ,, ultraviolet (UV), ,− mass, ,− Raman, and infrared (IR) ,, spectroscopy. However, there are no data in the literature on quantum chemical modeling of the absorption spectra of sulfur solutions, analysis of electronic transitions taking into account the structure and stability of solvates, and possible associates.…”