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过程工程学报 ›› 2019, Vol. 19 ›› Issue (6): 1129-1134.DOI: 10.12034/j.issn.1009-606X.219126

• 反应与分离 • 上一篇    下一篇

水合物法分离低浓度煤层气中的甲烷

吕秋楠1,2,3,4,5, 李小森1,2,3,4,5*, 李 刚1,2,3,4,5, 陈朝阳1,2,3,4,5   

  1. 1. 中国科学院广州能源研究所,广东 广州 510640 2. 中国科学院天然气水合物重点实验室,广东 广州 510640 3. 广东省新能源和可再生能源研究开发与应用重点实验室,广东 广州 510640 4. 中国科学院广州天然气水合物研究中心,广东 广州 510640 5. 中国科学院大学化学工程学院,北京 100049
  • 收稿日期:2019-01-23 修回日期:2019-04-08 出版日期:2019-12-22 发布日期:2019-12-22
  • 通讯作者: 李小森
  • 基金资助:
    二元水合物海水淡化过程中形成机理与动力学研究;天然气水合物分解机理及调控方法研究;多孔介质骨架结构对天然气水合物分解影响机理研究;促进剂体系中甲烷水合物生成机理及动力学研究

Separation of methane from low concentration coal bed methane by hydrate-based process

Qiunan LÜ1,2,3,4,5, Xiaosen LI1,2,3,4,5*, Gang LI1,2,3,4,5, Zhaoyang CHEN1,2,3,4,5   

  1. 1. Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou, Guangdong 510640, China 2. CAS Key Laboratory of Gas Hydrate, Guangzhou, Guangdong 510640, China 3. Guangdong Provincial Key Laboratory of New and Renewable Energy Research and Development, Guangzhou, Guangdong 510640, China 4. Guangzhou Center for Gas Hydrate Research, Chinese Academy of Sciences, Guangzhou, Guangdong 510640, China 5. School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-01-23 Revised:2019-04-08 Online:2019-12-22 Published:2019-12-22
  • Contact: LI Xiao-sen

摘要: 向模拟煤层气(13.11vol% CH4+86.89vol% N2)中添加5.8mol%四氢呋喃(THF)?0.03mol%十二烷基硫酸钠(SDS)促进剂溶液分离提纯煤层气,考察了压力、温度、反应时间对气体消耗量、反应速率、分解气中甲烷浓度、甲烷回收率和甲烷分离因子的影响,采用色谱分析法分别测定了CH4在剩余气相和分解气相中的浓度。结果表明,压力增加,CH4回收率增大,CH4分离因子增大,CH4分离效果越好;温度是影响甲烷分离因子的关键因素,温度降低,氮气和甲烷竞争进入水合物晶体中,导致水合物相中甲烷浓度降低;温度升高有利于提高水合物对甲烷的选择性。甲烷回收效率最高可达98.65%,分离因子最大为14.83。随反应时间增加,分解气中CH4浓度升高。

关键词: 水合物, 低浓度煤层气, 甲烷, 分离

Abstract: A method of separating and concentrating CH4 from coal bed methane (CBM) by hydrate formation was proposed. The separation experiments of CBM simulation gas (13.11vol% CH4+86.89vol% N2) were carried out by adding promoter solution of 5.8mol% Tetrahydrofuran (THF)?0.03mol% Sodium dodecyl sulfate (SDS). The effect of pressure, temperature and reaction time on gas consumption, reaction rate, methane concentration in the hydrate, methane recovery and separation factor were investigated. The concentrations of methane in the residual gas phase and the decomposed gas phase were determined by chromatographic analysis. The results indicated that the higher pressure, lower temperature, longer reaction time facilitated gas consumption, methane recovery and separation factor. With the increase of pressure, the recovery of CH4 and the separation factor of CH4 increased. It illustrated that higher pressure resulted in better separation efficiency for CBM. As the temperature decreased, nitrogen competed with methane to enter hydrate crystals, which led to the reduction of methane concentration in the hydrate phase. The temperature was the key factor affecting the methane separation factor, and the increase of temperature was propitious to improve the selectivity of methane hydrate. The maximum methane recovery rate was up to 98.65%, and the maximum separation factor was 14.83. With the increase of reaction time, the concentration of CH4 in decomposition gas increased. This indicated that CH4 and N2 molecules entered the hydrate lattice with the reaction proceeding, but the amount of CH4 entering the hydrate was more than that of N2 in the later stage of the reaction. This technology can effectively separate methane from low concentration coal bed methane and was valuable to storage and transportation of CBM and to disposal of mine methane.

Key words: hydrate, low concentration coal bed methane, methane, separate