Investigation of operating parameters on CO₂ splitting by dielectric barrier discharge plasma

Experiments of CO₂ splitting by dielectric barrier discharge (DBD) plasma were carried out, and the influence of CO₂ flow rate, plasma power, discharge voltage, discharge frequency on CO₂ conversion and process energy efficiency were investigated. It was shown that the absolute quantity of CO₂ decomposed was only proportional to the amount of conductive electrons across the discharge gap, and the electron amount was proportional to the discharge power; the energy efficiency of CO₂ conversion was almost a constant at a lower level, which was limited by CO₂ inherent discharge character that determined a constant gap electric field strength. This was the main reason why CO₂ conversion rate decreased as the CO₂ flow rate increase and process energy efficiency was decreased a little as applied frequency increased. Therefore, one can improve the CO₂ conversion by less feed flow rate or larger discharge power in DBD plasma, but the energy efficiency is difficult to improve.