Rational Design of CO2 Sorbents Based on Microwave-Matter Interaction for Rapid Dielectric Heating Regeneration

Abstract

Amine-based sorbents have emerged as robust materials for CO2 capture; however, they are associated with intensive energy consumption challenges during their thermal regeneration. Microwave dielectric heating facilitates the convenient and rapid regeneration of amine sorbents by directly and selectively heating the CO2-rich sorbent. Here, we propose the rational design of solid amine sorbents for their use of microwave-selective heating to release captured CO2 via ion-conduction microwave heating. We characterized the dielectric properties of a series of amines (primary, secondary, tertiary, cyclic, and aromatic amines) and found that ion formation is effective for both the CO2 capture and microwave absorption properties. By immobilizing monoethanolamine, which exhibited the highest ionic conductivity and CO2 capture capacity, on silica and zeolite supports, a 16-fold increase in the CO2 desorption rate was achieved compared with conventional heating under identical conditions. Overall, this study emphasizes a rapid CO2 sorbent recovery approach that combines commercially available materials with a microwave energy.