Polymeric membranes for CO2 separation and capture

Over the past decade, CO2 separation and capture have become the new bandwagon for polymer science and membrane research. This review presents the fundamentals of CO2/gas separation in polymeric membranes and discusses how these principles underpin opportunities and challenges for post-combustion carbon capture (CO2/N2), hydrogen purification (CO2/H2), and natural gas and biogas sweetening (CO2/CH4). Emerging polymeric membrane materials are discussed, including a few polymers containing a high content of polar functional groups (i.e., ether oxygen-rich polymers and polymeric ionic liquids), shape-persisting glassy polymers (i.e., perfluoropolymers, thermally rearranged polymers, iptycene-containing polymers), and reactive polymers featuring facilitated transport. Moreover, the promising candidates for each CO2 separation application are highlighted. Finally, the permeability-selectivity data reviewed were plotted against their 2008 and 2019 upper bounds.