| 초록 |
Some natural gas fields located in Southeast Asia contain high levels of CO2 content which can reduce energy density and increase production cost. Gas hydrate-based separation can be a good candidate for capturing CO2 from natural gas because the gas is obtained from high pressure reserviors. In this study, thermodynamic and structural analyses of the CH4 + CO2 hydrate were conducted in the presence of various thermodynamic hydrate promoters (THPs) such as tetrahydrofuran (THF), neohexane (NH), and tetra-n-butyl ammonium chloride (TBAC) in order to investigate CO2 capture characteristics depending on the structure. Three-phase (H-LW-V) or four-phase (H-LW-LNH-V) equilibria of the CH4 (50%) + CO2 (50%) + THP hydrates were measured to determine hydrate stability conditions. The phase equilibrium results showed that the addition of TBAC to the system resulted in the most significant thermodynamic promotion. Powder X-ray diffraction (PXRD) and Raman spectroscopy revealed that for the CH4 (50%) + CO2 (50%) gas mixture the addition of TBAC, THF, and NH induced the formation of semiclathrate, sII, and sH hydrate, respectively. |
