SCI和EI收录∣中国化工学会会刊

中国化学工程学报 ›› 2019, Vol. 27 ›› Issue (9): 2157-2163.DOI: 10.1016/j.cjche.2019.02.032

• Special Issue on Natural Gas Hydrate • 上一篇    下一篇

Investigation of the hydrate formation process in fine sediments by a binary CO2/N2 gas mixture

Xiaoya Zang, Lihua Wan, Deqing Liang   

  1. CAS Key Laboratory of Gas Hydrate, Guangzhou 510640, China;Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China;Guangzhou Institute of Energy Conversion, Guangzhou Center for Gas Hydrate Research, Chinese Academy of Sciences, Guangzhou 510640, China
  • 收稿日期:2018-12-05 修回日期:2019-02-20 出版日期:2019-09-28 发布日期:2019-12-04
  • 通讯作者: Deqing Liang
  • 基金资助:
    Supported by the National Key Research and Development Plan of China (2017YFC0307306), National Natural Science Foundation of China (51676197, 51576197), CAS Program (KGZD-EW-301), Guangzhou Science and Technology Project (201804010411), Youth Innovation Promotion Association CAS.

Investigation of the hydrate formation process in fine sediments by a binary CO2/N2 gas mixture

Xiaoya Zang, Lihua Wan, Deqing Liang   

  1. CAS Key Laboratory of Gas Hydrate, Guangzhou 510640, China;Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou 510640, China;Guangzhou Institute of Energy Conversion, Guangzhou Center for Gas Hydrate Research, Chinese Academy of Sciences, Guangzhou 510640, China
  • Received:2018-12-05 Revised:2019-02-20 Online:2019-09-28 Published:2019-12-04
  • Contact: Deqing Liang
  • Supported by:
    Supported by the National Key Research and Development Plan of China (2017YFC0307306), National Natural Science Foundation of China (51676197, 51576197), CAS Program (KGZD-EW-301), Guangzhou Science and Technology Project (201804010411), Youth Innovation Promotion Association CAS.

摘要: To obtain the fundamental data of CO2/N2 gas mixture hydrate formation kinetics and CO2 separation and sequestration mechanisms, the gas hydrate formation process by a binary CO2/N2 gas mixture (50:50) in fine sediments (150-250 μm) was investigated in a semibatch vessel at variable temperatures(273, 275, and 277 K)and pressures (5.8-7.8 MPa). During the gas hydrate reaction process, the changes in the gaseous phase composition were determined by gas chromatography. The results indicate that the gas hydrate formation process of the binary CO2/N2 gas mixture in fine sediments can be reduced to two stages. Firstly, the dissolved gas containing a large amount of CO2 formed gas hydrates, and then gaseous N2 participated in the gas hydrate formation. In the second stage, all the dissolved gas was consumed. Thus, both gaseous CO2 and N2 diffused into sediment. The first stage in different experiments lasted for 5-15 h, and >60% of the gas was consumed in this period. The gas consumption rate was greater in the first stage than in the second stage. After the completion of gas hydrate formation, the CO2 content in the gas hydrate was more than that in the gas phase. This indicates that CO2 formed hydrate easily than N2 in the binary mixture. Higher operating pressures and lower temperatures increased the gas consumption rate of the binary gas mixture in gas hydrate formation.

关键词: Gas hydrate, Formation, Sediments, CO2/N2 mixture

Abstract: To obtain the fundamental data of CO2/N2 gas mixture hydrate formation kinetics and CO2 separation and sequestration mechanisms, the gas hydrate formation process by a binary CO2/N2 gas mixture (50:50) in fine sediments (150-250 μm) was investigated in a semibatch vessel at variable temperatures(273, 275, and 277 K)and pressures (5.8-7.8 MPa). During the gas hydrate reaction process, the changes in the gaseous phase composition were determined by gas chromatography. The results indicate that the gas hydrate formation process of the binary CO2/N2 gas mixture in fine sediments can be reduced to two stages. Firstly, the dissolved gas containing a large amount of CO2 formed gas hydrates, and then gaseous N2 participated in the gas hydrate formation. In the second stage, all the dissolved gas was consumed. Thus, both gaseous CO2 and N2 diffused into sediment. The first stage in different experiments lasted for 5-15 h, and >60% of the gas was consumed in this period. The gas consumption rate was greater in the first stage than in the second stage. After the completion of gas hydrate formation, the CO2 content in the gas hydrate was more than that in the gas phase. This indicates that CO2 formed hydrate easily than N2 in the binary mixture. Higher operating pressures and lower temperatures increased the gas consumption rate of the binary gas mixture in gas hydrate formation.

Key words: Gas hydrate, Formation, Sediments, CO2/N2 mixture