Methane Storage and Purification of Natural Gas in Metal-Organic Frameworks.

Natural gas, primarily composed of methane (CH4), represent an excellent choice for a potentially sustainable renewable energy transition. However, the process of compressing and liquefying CH4 for transport and storage typically results in significant energy losses. In addition, in order to optimize its efficacy as a fuel, the CH4 content of natural gas needs to be increased to a level of at least 97 % to ensure its quality and efficiency in various applications. Metal-organic frameworks (MOFs) represent a novel category of porous materials that possess exceptional capability in modifying pore size and chemical environment, making them ideally suited for the storage of CH4 and the adsorption of propane (C3H8), ethane (C2H6), carbon dioxide (CO2), nitrogen (N2), and hydrogen sulfide (H2S) to facilitate the purification process of CH4 from natural gas. In this paper, we systematically summarize the mechanism by which MOF materials facilitate the storage of CH4 and the purification of CH4 from natural gas, leveraging the structural characteristics inherent to MOF materials. The focus of further research should also be directed towards the investigation of CH4 storage by flexible MOFs, the resolution of the trade-off dilemma, and the commercial application of MOFs.