Performance of CO2 decomposition in water-cooling DBD plasma reactor

Low-temperature plasma is recognized as a CO2 decomposition technology with substantial sustainable potential. Enhancing energy efficiency remains a critical challenge for plasma technology to achieve broader industrial adoption. This study developed two water electrode reactors-one with a stationary water electrode and the other with a flowing water electrode-designed to enhance energy efficiency in the CO2 decomposition process. A systematic performance comparison was subsequently made with a conventional aluminum mesh electrode reactor. The findings revealed that water electrode reactors significantly enhanced both heat transfer efficiency and power factor, thereby improving CO2 conversion performance. The stationary water reactor achieved a peak energy efficiency of 20.64%. The effects of input power, feed flow rate, and N2 content on dielectric barrier discharge plasma performance under high flow rate conditions were also explored in this study. The results indicated that as the input power increased, discharge intensity in all three reactors were intensified, leading to higher CO2 conversion. However, a portion of the energy was dissipated as heat, which gradually diminished overall energy efficiency. When the feed flow rate increased from 150 sccm to 600 sccm, the shorter residence time resulted in decreased CO2 conversion, while overall energy efficiency improved significantly. Increasing the N2 content caused an exponential rise in CO2 conversion, while the effective conversion rate and energy efficiency did not improve accordingly. Compared to previous studies, this research demonstrates a clear advantage in energy efficiency, offering useful insights for the industrial application of plasma technology in CO2 decomposition.