Gas solubility in ionic liquids.

Hydrogen sulfide removal is a long-standing economic and environmental challenge faced by the oil and gas industries. H2S separation processes using reactive and non-reactive absorption and adsorption, membranes, and cryogenic distillation are reviewed. A detailed discussion is presented on new developments in adsorbents, such as ionic liquids, metal oxides, metals, metal–organic frameworks, zeolites, carbon-based materials, and composite materials; and membrane technologies for H2S removal. This Review attempts to exhaustively compile the existing literature on sour gas sweetening and to identify promising areas for future developments in the field.

https://pubs.acs.org/doi/pdf/10.1021/acs.chemrev.7b00768

Hydrogen Sulfide Capture: From Absorption in Polar Liquids to Oxide, Zeolite, and Metal-Organic Framework Adsorbents and Membranes.

Gaseous solubilities of carbon dioxide (1), hydrogen sulfide (2), and their binary mixture (x2 ≈ 0.2, 0.5, 0.8) have been measured in the ionic liquid 1-octyl-3-methylimidazolium bis(trifluoromethy...

Solubility of CO2, H2S, and their mixture in the ionic liquid 1-octyl-3-methylimidazolium bis(trifluoromethyl)sulfonylimide.

Gaseous solubilities of carbon dioxide (1), hydrogen sulfide (2), and their binary mixture (x₂ ≈ 0.2, 0.5, 0.8) have been measured in the ionic liquid 1-octyl-3-methylimidazolium bis(trifluoromethyl)sulfonylimide ([C₈mim][Tf₂N]) at temperatures ranging from (303.15 to 353.15) K and at pressures under 2 MPa. The observed PTx solubility data were used to obtain Henry's law constants and correlated by three models: (1) the simple Krichevsky–Kasarnovsky (KK) equation, (2) a model comprised of the extended Henry's law and the Pitzer's virial expansion for the excess Gibbs free energy, and (3) the generic Redlich–Kwong (RK) cubic equation of state proposed for gas–ionic liquid systems. The correlations from the three models show quite good consistency with the experimental data for IL/CO₂ and IL/H₂S binary mixtures within experimental uncertainties. For IL/CO₂/H₂S ternary mixtures, the RK model shows the best correlation with the experimental data. The comparison showed that the solubility of H₂S is about two times as great as that of CO₂ in the ionic liquid studied in this work. It was further found, by comparison of the experimental data of this study with those of previous reports, that the solubility of H₂S in [Cₙmim][Tf₂N] ILs increases as the number of carbon atoms in the alkyl substituent of methylimidazolium cation, n, increases. In addition, quantum chemical calculations at DFT/B3LYP level of theory using 6-311+G(d) and 6-311++G(2d,2p) basis sets were performed on the isolated systems studied in this work to provide explanations from a molecular point of view for the observed experimental trends.

Solubility of CO2, H2S, and Their Mixture in the Ionic Liquid 1-Octyl-3-methylimidazolium Bis(trifluoromethyl)sulfonylimide B

Ionic liquid-amine blends and CO2BOLs: Prospective solvents for natural gas sweetening and CO2 capture technology—A review

The solubility of hydrogen sulfide gas in ionic liquids (ILs) 1-ethyl-3-methylimidazolium hexafluorophosphate ([emim][PF6]) at temperatures from (333.15 to 363.15) K and 1-ethyl-3-methylimidazolium bis(trifluoromethyl)sulfonylimide ([emim][Tf2N]) at temperatures ranging from (303.15 to 353.15) K and pressures up to about 2.0 MPa was measured using a volumetric based static apparatus. The solubility data were correlated using two models: the Krichevsky−Kasarnovsky (KK) equation, and the extended Henry’s law combined with the Pitzer’s virial expansion for the excess Gibbs energy. Henry’s law constants (at zero pressure) were obtained at different temperatures from the obtained experimental solubility data. Using the solubility data, the partial molar thermodynamic functions of solution, that is, Gibbs energy, enthalpy, and entropy were calculated. A comparison showed that the solubility of H2S in [emim][Tf2N] is greater than [emim][PF6].

Solubility of H2S in Ionic Liquids 1-Ethyl-3-methylimidazolium Hexafluorophosphate ([emim][PF6]) and 1-Ethyl-3-methylimidazolium Bis(trifluoromethyl)sulfonylimide ([emim][Tf2N])

Hossein Sakhaeinia

Papers

Solubility of H2S in Ionic Liquids 1-Ethyl-3-methylimidazolium Hexafluorophosphate ([emim][PF6]) and 1-Ethyl-3-methylimidazolium Bis(trifluoromethyl)sulfonylimide ([emim][Tf2N])