Dissociation Conditions and Raman Spectra of CO2 + SO2 and CO2 + H2S Hydrates

Abstract

To further define the information needed for CO2 gas sequestration and storage in the presence of impurities, the stability of hydrates made from CO2 + SO2 and CO2 + H2S mixtures was measured by an isochoric dissociation method. The hydrates were characterized with powder X-ray diffraction, confirming that CO2 + SO2 formed a structure I hydrate. The Raman spectra of CO2 + SO2 and CO2 + H2S hydrates were also measured along with those of THF + CO2 + SO2 and THF + CO2 + H2S hydrates to observe and assign the Raman peaks of SO2 or H2S in the small cages. It was found the SO2 Raman peaks are at 1147.1 and 1155.4 cm–1 in large and small cages, respectively; the H2S Raman peaks are at 2594.0 and 2603.0 cm–1 in large and small cages, respectively. At the equilibrium points established, the composition of the released gas mixture was analyzed by gas chromatography. Measurements for gas pressures (ranging from 0.72 to 3.59 MPa) and gas compositions (ranging from 0.04% to 7.63%, mole fraction of SO2 or H2S) at spec...