C2s/C1 hydrocarbon separation: The major step towards natural gas purification by metal-organic frameworks (MOFs)

Gas separation processes have significant impacts on human society’s current needs, starting from industrial, environmental, energy to high-value chemical necessities. Natural gas (NG) is used in various sectors across the globe and accounted to 32% of U.S. total primary energy consumption in 2019. Raw NG consisting primarily of C1 hydrocarbon (CH4) possesses a significant amount of C2 hydrocarbons (5–9%) which needs to be removed and considered as the major step of NG processing. The high cost associated with the cryogenic high-pressure distillation process for the separation of C2s/C1 hydrocarbons from NG restricts its widespread usage. Porous metal-organic frameworks (MOFs), offer remarkable promise for such C2s/C1 hydrocarbon separations because of their easy tunability, functionality, and designability. Around a hundred of MOFs have been designed and synthesized for the potential applications in C2s/C1 hydrocarbon separations. Such reports are increasing swiftly and thus demands a summarization for at a glance visualization. In this review, we intend to showcase the development of MOFs with the superiority over other developed porous materials for such separation. We have described the strategies taken to obtain the trade-off between C2s sorption capacity and separation selectivity of C2s/C1. Furthermore, the challenges and future prospects are discussed elaborately.