Conversion of carbon dioxide in microwave plasma torch sustained by gyrotron radiation at frequency of 24 GHz at atmospheric pressure

Abstract The first experimental results of using focused continuous microwave radiation of the gyrotron at a frequency of 24 GHz and power up to 5 kW for carbon dioxide decomposition are presented. The experiments were performed in pure CO2 and CO2/Ar mixture at atmospheric pressure. The highest conversion of 31.3% was observed at the CO2/Ar ratio of 1:5 at the optimum total gas flow rate of 30 LPM, while the energy efficiency was about 9.5% at SEI of 4.7 eV/molecule. The optical spectroscopy measurements confirmed that non-equilibrium plasma of microwave discharge with electron temperature not less than 4000−8000 K (0.3−0.7 eV) and gas temperature at the level of 2000−3500 K, is well suited for the effective decomposition of carbon dioxide.