Design of highly regenerable zeolite-based carbon-dioxide adsorbent in temperature swing adsorption

Abstract

Solid adsorbents such as amine-included materials and zeolites have been widely investigated for post-combustion $CO_2$ capture. Amine-included porous materials have shown promising $CO_2$ uptake in a wet flue gas, but suffer from amine deactivation due to urea formation under a desorption condition (e.g., desorption under pure $CO_2$ at the temperature higher than $130^\circ C$) of temperature swing adsorption (TSA) cycles. In contrast, purely inorganic zeolites are thermochemically stable but do not adsorb $CO_2$ from a wet flue gas because of the preferential $H_2O$ adsorption. In the present work, we synthesized an amine-grafted Y zeolite, which can synergistically combine the strengths of both adsorbent systems. The amine groups can effectively capture $CO_2$ in a wet flue gas, while the strongly co-adsorbed $H_2O$ within the hydrophilic zeolite micropores suppresses urea formation. Because the adsorbent is prepared from a commercially available zeolite, it is also cost efficient and suitable for mass production.