Design and structuring of porous sorbents for CO₂ capture and separation

CO₂ capture and conversion using structured porous sorbents and catalysts is a solution to help the decarbonization of emission-intensive industries. Furthermore, porous sorbents have recently been considered for direct air capture to achieve negative CO₂ emissions. Several new prototypes and swing adsorption technologies for CO₂ capture use structured laminates and honeycomb sorbents to lower the energy penalty and improve process efficiency and kinetics. The challenges lie in tailoring and optimizing structured sorbents for their CO₂ working capacity, selectivity over other components, the effect of impurities and humidity, mass and heat transfer kinetics, and mechanical and chemical durability, which are specific to the exhaust system and flue gas composition. Recent developments in the structuring of sorbents are reviewed with a focus on the scalable approaches to improve the performance of postcombustion CO₂ capture and direct air capture processes.