| 초록 |
CO2 in acidic natural gas stream is considered as the main contaminant to be separated for higher calorific efficiency and GHG emission reduction. In this study, CO2(50%)/CH4(50%) gas was used to observe CO2 capture from acidic natural gas using hydrate based gas separation (HBGS) which is one of the promising gas separation technology. In order to identify thermodynamic property of CO2/CH4 mixed gas hydrate, three phase equilibrium (H-Lw-V) was measured and compared to the phase equilibria with thermodynamic promoters; THF and TBAC. The phase equilibrium temperature was increased by 16K with 5.6mol% THF and 13.5K with 3.3mol% of TBAC at 3MPa. CO2 composition in the hydrate phase increased to 77% in the TBAC hydrate and decreased to 44% in THF hydrate from 50% of CO2 in feed gas. TBAC showed higher selectivity by thermodynamic and structural effects despite lower gas capacity than pure water hydrate. Furthermore, kinetic characteristics were observed by in-situ Raman spectroscopy. Hydrate cage growth in THF system was faster than pure water and TBAC, and the faster growth of CO2 than CH4 was investigated in the early stage. |
