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Experimental Study on the Effect of Pressure on the Replacement Process of CO2–CH4 Hydrate below the Freezing Point
- Zhang, Xuemin, Li, Yang, Yao, Ze, Li, Jinping, Wu, Qingbai, Wang, Yingmei
- Energy & fuels 2018 v.32 no.1 pp. 646-650
- carbon dioxide, freezing point, ice, methane, methane production, natural gas, particle size, permafrost, temperature
- The recovery of natural gas from CH₄ hydrate deposits in permafrost environments through injection of CO₂ is considered to be a suitable strategy for CH₄ production and CO₂ storage. To study the replacement characteristics of CO₂–CH₄ hydrate below the freezing point, the experiment was conducted in ice powder with particle size of 800 μm at different injection pressures (3.6, 4.0, and 4.5 MPa) of CO₂. The experimental results showed that the average replacement rate and efficiency increased with the increasing of injected pressure of CO₂ gas. Also, the average replacement rate and efficiency reached up to 0.403 mmol/h and 13.20% when the injected pressure of CO₂ was at 4.5 MPa. The results also indicated that, compared with the temperature conditions above the freezing point, the replacement rate of CO₂–CH₄ hydrate was slow below the freezing point. These results provide a theoretical guidance for gas production from methane hydrate using CO₂–CH₄ replacement method in permafrost region in the future.