Breaking boundaries in CO2 capture: Ionic liquid-based membrane separation for post-combustion applications

As a part of global warming reduction strategies, CO2 capture and storage (CCS) is considered a promising and effective method, which can be classified as absorption and adsorption, chemical looping combustion and cryogenic distillation, hydrate-based separation, and membrane separation. But, the high energy requirement, solvent loss and degradation, corrosive nature, and toxicity of solvents can limit the applications. Developing novel techniques and materials are attracting high attention to achieve superior capacities. The supported ionic liquid membranes (SILMs) as a part of ionic liquids (ILs) have shown great potential for efficient and cost-effective separation of CO2 from the gaseous flow. The present review demonstrates the mechanisms, advantages, difficulties, and disadvantages of CO2 capture by SILMs and compares them with various conventional methods. A major part of this review covers the tunability of SILMs, experimental data of solubility, diffusivity, permeability, and selectivity of CO2 in various combinations of ILs, membrane supports, and additives. Lastly, the stability of SILMs, reusability of ILs, membrane wetting, challenges, and future recommendations are presented. © 2023 The Authors