CO2 capture by amine infused hydrogels (AIHs)

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.