Amine Infused Fly Ash Grafted Acrylic Acid/Acrylamide Hydrogel for Carbon Dioxide (CO₂) Adsorption and Its Kinetic...

In most carbon dioxide (CO₂) capture processes, chemical absorption using an amine solvent is widely used technology; however, the solvent is prone to solvent degradation and solvent loss which leads to the formation of corrosion. This paper investigates the adsorption performance of amine-infused hydrogels (AIFHs) to increase carbon dioxide (CO₂) capture by leveraging the potency of amine absorption and adsorption properties of class F fly ash (FA). The solution polymerization method was used to synthesize the FA-grafted acrylic acid/acrylamide hydrogel (FA-AAc/AAm), which was then immersed in monoethanolamine (MEA) to form amine infused hydrogels (AIHs). The prepared FA-AAc/AAm showed dense matrices morphology with no obvious pore at the dry state but capable of capturing up to 0.71 mol/g CO₂ at 0.5 wt% FA content, 2 bar pressure, 30 °C reaction temperature, 60 L/min flow rate, and 30 wt% MEA contents. Cumulative adsorption capacity was calculated and Pseudo-first order kinetic model was used to investigate the CO₂ adsorption kinetic at different parameters. Remarkably, this FA-AAc/AAm hydrogel is also capable of absorbing liquid activator that was 1000% more than its original weight. FA-AAc/AAm can be used as an alternative AIHs that employ FA waste to capture CO₂ and minimize the GHG impact on the environment.