CO2 capture by amine infused hydrogels (AIHs)

Abstract

We report a proof-of-concept study on an entirely new class of CO₂ absorbent which is prepared by simply adding commercially available hydrogels into organic amine solutions to generate amine infused hydrogels (AIHs). The hydrogel ensures that the CO₂–amine reactions are maintained in AIHs but the interfacial area/kinetics for these interactions is significantly increased. As a result, this new material rapidly captures CO₂ with higher overall uptake compared to the commonly used aqueous amine solutions under similar experimental conditions. It reaches exceptional CO₂ uptake without the need for stirring. In terms of recycling, the absorption capacity of AIHs is well maintained after multiple regeneration cycles if high molecular weight amines and a suitable hydrogel are applied. Moreover, the hydrogel can easily be recovered and reused, noticeably reducing material costs. In all, this proof-of-concept study demonstrates that by using an inexpensive and readily available material (hydrogel), AIHs show promise as a CO₂ absorbent.