SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2019, Vol. 27 ›› Issue (9): 2207-2212.DOI: 10.1016/j.cjche.2019.02.035

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Decomposition behaviors of methane hydrate in porous media below the ice melting point by depressurization

Yu Zhang1,2,3, Tian Wang1,2,3,4, Xiaosen Li1,2,3, Kefeng Yan1,2,3, Yi Wang1,2,3, Zhaoyang Chen1,2,3   

  1. 1 Guangzhou Institute of Energy Conversion, Key Laboratory of Gas Hydrate, Chinese Academy of Sciences, Guangzhou 510640, China;
    2 Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China;
    3 Guangzhou Center for Gas Hydrate Research, Chinese Academy of Sciences, Guangzhou 510640, China;
    4 University Science & Technology of China, Nano Science & Technology Institute, Suzhou 215123, China
  • Received:2018-11-16 Revised:2019-01-25 Online:2019-12-04 Published:2019-09-28
  • Contact: Xiaosen Li
  • Supported by:
    Supported by Key Program of National Natural Science Foundation of China (51736009), the National Natural Science Foundation of China (51476174, 51576202 and 51376183), National Key Research and Development Plan of China (2016YFC0304002), Special Project for Marine Economy Development of Guangdong Province (GDME-2018D002), and Natural Science Foundation of Guangdong Province, China (2017A030313301).

Decomposition behaviors of methane hydrate in porous media below the ice melting point by depressurization

Yu Zhang1,2,3, Tian Wang1,2,3,4, Xiaosen Li1,2,3, Kefeng Yan1,2,3, Yi Wang1,2,3, Zhaoyang Chen1,2,3   

  1. 1 Guangzhou Institute of Energy Conversion, Key Laboratory of Gas Hydrate, Chinese Academy of Sciences, Guangzhou 510640, China;
    2 Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China;
    3 Guangzhou Center for Gas Hydrate Research, Chinese Academy of Sciences, Guangzhou 510640, China;
    4 University Science & Technology of China, Nano Science & Technology Institute, Suzhou 215123, China
  • 通讯作者: Xiaosen Li
  • 基金资助:
    Supported by Key Program of National Natural Science Foundation of China (51736009), the National Natural Science Foundation of China (51476174, 51576202 and 51376183), National Key Research and Development Plan of China (2016YFC0304002), Special Project for Marine Economy Development of Guangdong Province (GDME-2018D002), and Natural Science Foundation of Guangdong Province, China (2017A030313301).

Abstract: The decomposition behaviors of methane hydrate below the ice melting point in porous media with different particle size and different pore size were studied. The silica gels with the particle size of 105-150 μm, 150-200 μm and 300-450 μm, and the mean pore diameters of 12.95 nm, 17.96 nm and 33.20 nm were used in the experiments. Methane recovery and temperature change curves were determined for each experiment. The hydrate decomposition process in the experiments can be divided into the depressurization period and the isobaric period. The temperature in the system decreases quickly in the depressurization process with the hydrate decomposition and reaches the lowest point in the isobaric period. The hydrate decomposition in porous media below ice-melting point is very fast and no self-perseveration effect is observed. The hydrate decomposition is influenced both by the driving force and the initial hydrate saturation. In the experiments with the high hydrate saturation, the hydrate decomposition will stop when the pressure reaches the equilibrium dissociation pressure. The stable pressure in the experiment with high hydrate saturation exceeds the equilibrium dissociation pressure of bulk hydrate and increases with the decrease of the pore size.

Key words: Methane hydrate, Depressurization, Porous media, Decomposition, Ice-melting point

摘要: The decomposition behaviors of methane hydrate below the ice melting point in porous media with different particle size and different pore size were studied. The silica gels with the particle size of 105-150 μm, 150-200 μm and 300-450 μm, and the mean pore diameters of 12.95 nm, 17.96 nm and 33.20 nm were used in the experiments. Methane recovery and temperature change curves were determined for each experiment. The hydrate decomposition process in the experiments can be divided into the depressurization period and the isobaric period. The temperature in the system decreases quickly in the depressurization process with the hydrate decomposition and reaches the lowest point in the isobaric period. The hydrate decomposition in porous media below ice-melting point is very fast and no self-perseveration effect is observed. The hydrate decomposition is influenced both by the driving force and the initial hydrate saturation. In the experiments with the high hydrate saturation, the hydrate decomposition will stop when the pressure reaches the equilibrium dissociation pressure. The stable pressure in the experiment with high hydrate saturation exceeds the equilibrium dissociation pressure of bulk hydrate and increases with the decrease of the pore size.

关键词: Methane hydrate, Depressurization, Porous media, Decomposition, Ice-melting point