Nonthermal plasma assisted desorption and conversion of captured CO2 from atmospheric air

Abstract

CO₂ capture and conversion are essential to mitigate the global climate crisis. However, sorbent regeneration frequently relies on the high-temperature thermal-driven process, making the integration of intermittent renewable energy into the process an inherent challenge. Herein, with a lime-based sorbent model system, we show that an electrified process for the desorption and conversion of captured CO₂ (to CO or CH₄) can be achieved through a non-thermal dielectric-barrier discharge plasma reactor. Specifically, up to 87.7% of captured CO₂ (by CaO from the air) can be converted into CO under the discharge of 10% H₂/Ar at a power of 24.7 W. The reaction can also be tuned for CH₄ production when a dual function material, Ni–Ru CaO/CeO₂–Al₂O₃, or a physical mixture of CaO and a Ru/Al₂O₃ methanation catalyst is employed. The kinetics of such a process are evaluated based on the nonsteady-state semi-batch reactor model. The reactions are identified to be first order for both CO₂ desorption and hydrogenation processes.