Recent progress on functional polymeric membranes for CO₂ separation from flue gases: A review

The separation of CO₂ has been recognized as a potential approach to address the impacts of climate change resulting from the emission of flue gases into the environment. Efficient separation technologies are required to effectively remove CO₂ from flue gases. To resolve this problem, membrane-based gas separation is considered an economically viable and energy-efficient technology over conventional techniques. Functional polymeric membranes have gained a lot of interest for their attractive gas separation performance. Thus, this work aims to critically review the recent developments of functional polymeric membranes designed for CO₂ separation from flue gases. Starting with a background on flue gases and polymeric membranes, a brief discussion on Robeson's upper bound for CO₂/N₂ separation is provided. After that, a detailed analysis of the current advancements in different membrane modification approaches, such as mixed matrix, grafting, layer-by-layer assembly, and interfacial polymerization, for improved performance of polymeric membranes is provided. Furthermore, the effect of CO₂ on polymeric membranes (plasticization and aging), the current global market and key market players in the membranes-based gas separation field are discussed thoroughly. Finally, a concise remark on the future directions of polymeric membranes for CO₂ separation from flue gases is presented.