Design and characterization of an electromagnetic-resonant cavity microwave plasma reactor for atmospheric pressure carbon dioxide decomposition

Plasma processes are ideally suited for the conversion of renewable electricity into gas-phase reactivity, such as for the decomposition of carbon dioxide (CO₂). The design, development, and characterization of a microwave plasma reactor for atmospheric pressure undiluted carbon dioxide decomposition are presented. The reactor operates as an electromagnetic-resonant cavity in which the generated plasma forms a bulb attached to a converging-diverging nozzle and stabilized by streams of tangentially injected processing gas. Electromagnetic wave confinement, residence time, and critical gas vorticity constitute fundamental reactor sizing and operation parameters. Experimental results show that flow rate plays a dual role in plasma stabilization and process performance, whereas deposited power has a minor role in CO₂ decomposition.