| 초록 |
The gas hydrate replacement using CO2 injection has been considered as a promising natural gas production technology which can function as both energy recovery and CO2 sequestration. In this study, structure I and H hydrates were formed with CH4 and CH4 + methylcyclopentane (MCP), respectively. To examine the effect of the CO2 injecting pressure on the replacement behavior, the replacement experiment was conducted at pressure ranges where pure CO2 hydrate is thermodynamically stable and gaseous CO2 is not liquefied. To identify the replacement efficiency of each experiment, the compositions of hydrate phase were measured by gas chromatography. In addition, Raman spectroscopy, 13C NMR, and powder X-ray diffraction were used to observe the guest exchange behavior and structural information of gas hydrates during the replacement. In case of sH hydrate, the replacement efficiency was increased with increasing the CO2 injecting pressure. However, for sI hydrate, the replacement efficiency was found to be almost constant irrespective of experimental pressure. |
