China Coal Research Institute Corporation Ltd.
National Energy Technology & Equipment Laboratory of CoalUtilization and Emission Control
Beijing Key Laboratory of Coal based Carbon Materials

煤层气等非常规天然气的开发与利用可有效缓解天然气不足且能降低其直接排放所造成的资源浪费与温室效应,其中甲烷(CH4)与氮气(N2)的分离技术已成为低浓度煤层气提浓的关键要素,因而对煤层气中的甲烷与氮气分离技术研究进展进行汇总分析,以期为该分离技术的实际应用奠定基础以及助力于推动规模化浓缩低浓度甲烷气的工业化进程。对近年CH4与N2分离技术的研究现状进行归纳分析,阐述CH4与N2主要分离技术的研究特点,具体探讨深冷分离、变压吸附分离、膜分离以及溶剂吸收分离等技术用于CH4与N2分离的国内外研究进展。研究表明:深冷分离技术具有技术成熟且产品气CH4的纯度与回收率均高的特点,但仅在大型煤矿分离大规模煤层气时较适用;变压吸附技术具有耗能低、分离效果佳等特点,目前已成为最具工业化应用前景的CH4和N2分离技术,开发价格低廉、高性能的活性炭、碳分子筛、沸石分子筛、金属有机骨架材料(MOF)等吸附剂是变压吸附的核心,未来需调控吸附剂的孔道结构与优化其表面性质;膜分离技术用于CH4与N2分离时具有占地少、低能耗和污染小等优点,可提高聚合物膜、无机膜、MOF气体分离膜等的分离效率、经济性与使用寿命,注重提升膜分离性能以提高膜材料对复杂油气环境的适应性,即设计和筛选性能优异的底膜材料已成为膜分离CH4/N2工业化应用的重要方向;溶剂吸收分离技术由于存在CH4和N2在溶剂中的溶解度较小、再生解吸较困难、吸收剂的使用量大等问题,导致溶剂吸收分离技术用于CH4/N2的实际工业应用时受到一定的限制。

The exploration and utilization of unconventional natural gas such as coalbed methane can effectively alle viate the problem of natural gas shortage and reduce the resource waste and greenhouse effect caused by its direct e missions, among them, the separation of methane (CH4) and nitrogen (N2) has become the key point in the con centration enhancement of low concentration coalbed methane. Summarizing and analyzing the research progress of methane and nitrogen separation technology in coalbed methane can lay a foundation for the practical application of separation technology and help promote the industrialization process of largescale concentration of low concentration methane gas. The current research status of CH4 and N2 separation technologies in recent years were summarized, characteristics of the main separation technologies for CH4 and N2were demonstrated, the research progress of technol ogies such as cryogenic separation, pressure swing adsorption separation, membrane separation, and solvent absorp tion separation for the separation of CH4 and N2 both domestically and internationally were discussed. The cryogenic separation technology is mature and the product gas CH4 has high purity and recovery rate, but it is only suitable for separating largescale coalbed methane in large coal mines; pressure swing adsorption technology has the characteris tics of low energy consumption and good separation effect, at present, it has become the most promising CH4 and N2separation technology for industrial applications. The development of lowcost and highperformance adsorbents such as activated carbon, carbon molecular sieves, zeolite molecular sieves, and metal organic framework materials (MOF) is the core of pressure swing adsorption, in the future, it is necessary to regulate the pore structure of adsor bents and optimize their surface properties; membrane separation technology for CH4 and N2 separation has the advan tages of small land occupation, low energy consumption, and low pollution, which can improve the separation effi ciency, economy, and service life of polymer membranes, inorganic membranes, MOF gas separation membranes, etc. Emphasizing the improvement of membrane separation performance to enhance the adaptability of membrane ma terials to complex oil and gas environments is important, that is, designing and screening bottom membrane materials with excellent performance has become an important direction for the industrial application of membrane separation of CH4 / N2. The solvent absorption separation technology is limited in practical industrial applications of CH4 / N2 due to the low solubility of CH4 and N2 in solvents, difficulty in regeneration desorption, and high usage of absorbents.

天地科技股份有限公司科技创新创业资金专项基金资助青年项目(2023-TD-QN002)

李小亮.煤层气中的甲烷与氮气分离技术研究进展[J].煤质技术,2024,39(2):43-52.

LI Xiaoliang. Research progress in separation technology of methane and nitrogen from coalbed methane [J]. CoalQuality Technology, 2024, 39 (2): 43-52.