Dielectric barrier discharge plasma assisted CO 2 conversion: understanding the effects of reactor design and operating parameters

The experimental study of CO 2 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 CO 2 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 CO 2 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 CO 2 conversion and energy efficiency when other parameters are kept constant. The higher input power or the lower CO 2 flow rate leads to the increase of CO 2 conversion, while energy efficiency descends. In addition, the produced activated species in CO 2 plasma are detected via spectrum analysis, including CO, and OH.