Carbon Dioxide Conversion in a Portable Atmospheric Microwave Plasma with High Energy Efficiency

The conversion of carbon dioxide (CO2) driven by microwave plasma has garnered extensive attention due to its capability to recycle carbon resources and mitigate the greenhouse effect. However, the existing microwave plasma technologies suffer from cumbersome system setups and relatively low energy efficiency. This work investigates CO2 conversion using a portable atmospheric microwave plasma source, which requires low plasma-generating power. When the working gas is a mixture of CO2 and Ar, the minimum plasma-generating power required for the proposed portable microwave plasma source is only 50 W. A Fourier transform infrared spectrometer is used to quantify both the CO2 and CO concentrations, and the C2 Swan bands in the plasma are measured to determine the gas temperature. The maximum CO2 conversion rate is approximately 12.7%. Furthermore, the maximum energy efficiency reaches 87.9%, which exceeds that of most state-of-the-art atmospheric microwave plasma configurations. Owing to its simplicity of operation, portability, and high energy efficiency, this method is well-suited for distributed CO2 conversion systems.