Dielectric barrier discharge plasma assisted CO2 conversion: understanding the effects of reactor design and operating parameters

The experimental study of CO2 conversion is carried out in a coaxial cylinder dielectric barrier discharge reactor at atmospheric pressure, investigating the effects of internal electrode and different plasma processing parameters (discharge frequency, input power and feed flow rate) on CO2 conversion and energy efficiency. The major products of CO(2 )splitting are CO and O-2. The results show that the use of compact conductive powder as internal electrode gives rise to a stronger discharge, higher energy efficiency, maximum CO2 conversion and CO yield. Using copper powder as inner electrode obtains the enhanced CO yield, increasing by 138.46% than that of an electrode made of compact carbon powder and 50.33% than that of an electrode made of compact iron powder. Discharge frequency has a weak effect on CO2 conversion and energy efficiency when other parameters are kept constant. The higher input power or the lower CO2 flow rate leads to the increase of CO2 conversion, while energy efficiency descends. In addition, the produced activated species in CO2 plasma are detected via spectrum analysis, including CO, CO2+ and OH.