Thermodynamic Stability, Spectroscopic Identification, and Gas Storage Capacity of CO2鈥揅H4鈥揘2 Mixture Gas Hydrates: Implications for Landfill Gas Hydrates

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• 作者：Hyeong-Hoon Lee ; Sook-Hyun Ahn ; Byong-Uk Nam ; Byeong-Soo Kim ; Gang-Woo Lee ; Donghyun Moon ; Hyung Joon Shin ; Kyu Won Han ; Ji-Ho Yoon
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：April 3, 2012
• 年：2012
• 卷：46
• 期：7
• 页码：4184-4190
• 全文大小：322K
• 年卷期：v.46,no.7(April 3, 2012)
• ISSN：1520-5851

文摘

Landfill gas (LFG), which is primarily composed of CH₄, CO₂, and N₂, is produced from the anaerobic digestion of organic materials. To investigate the feasibility of the storage and transportation of LFG via the formation of hydrate, we observed the phase equilibrium behavior of CO₂鈥揅H₄鈥揘₂ mixture hydrates. When the specific molar ratio of CO₂/CH₄ was 40/55, the equilibrium dissociation pressures were gradually shifted to higher pressures and lower temperatures as the mole fraction of N₂ increased. X-ray diffraction revealed that the CO₂鈥揅H₄鈥揘₂ mixture hydrate prepared from the CO₂/CH₄/N₂ (40/55/5) gas mixture formed a structure I clathrate hydrate. A combination of Raman and solid-state ¹³C NMR measurements provided detailed information regarding the cage occupancy of gas molecules trapped in the hydrate frameworks. The gas storage capacity of LFG hydrates was estimated from the experimental results for the hydrate formations under two-phase equilibrium conditions. We also confirmed that trace amounts of nonmethane organic compounds do not affect the cage occupancy of gas molecules or the thermodynamic stability of LFG hydrates.