Cold plasma activated CO2desorption from calcium carbonate for carbon capture

Abstract

This work investigates the non-equilibrium regeneration of one scalable sorbent material for carbon capture, calcium oxide, in a customized flow reactor coupled to a low-temperature atmosphericpressure plasma source. The results show that such a plasma is capable of desorbing CO2 from CaCO3, with an operating temperature far below the thermal decomposition temperature of carbonate. The desorbed CO2 is further converted to CO in situ. The energy cost is 1.90 × 103 kWh per tCO2, as the same order of magnitude as the state-of-the-art high temperature regeneration technology. A nonequilibrium kinetic mechanism is proposed in which CO2 desorption is coupled into air plasma chemistry. Electron-impact reactions in air lead to the generation of vibrationally excited nitrogen and ozone. Subsequent quenching of atomic oxygen on the carbonate surface can regenerate CaO, while NOx will pollute the surface. Compared with the previous methods used in sorbent regeneration, plasma-based technologies offer an electrified, sustainable, and low-temperature solution based on the non-equilibrium plasma chemistry. Possible scaling strategies include fluidization, flow pulsation, and plasma catalysis. This work demonstrates the feasibility of non-equilibrium plasma processing of the sorbent material for cyclic capture and regeneration in atmospheric air using thermally low-intensity processes.