Carbon dioxide conversion by means of coplanar dielectric barrier discharges

To face the worldwide problem of anthropogenic carbon dioxide (CO2) emission new techniques have to be developed. One approach for carbon capture utilization (CCU) is the conversion of CO2 to more valuable chemicals, e. g., carbon monoxide (CO) by means of non- thermal plasma generated at ambient conditions and supplied by excess energy from renewable sources. This paper reports about the effect of the admixture of inert gases, namely nitrogen or argon to CO2 in a coplanar dielectric barrier discharge (DBD). Systematic experiments were conducted to investigate the effects of applied voltage, frequency, flowrate and CO2 concentration in the influent. The composition of products, energy efficiency and yield were determined. Within the investigated parameter ranges, the maximum conversion of CO2 to CO efficiency of 1% was achieved when the specific input energy was 190 J L-1, whereas the maximum CO yield of 0.7% was achieved when the specific input energy was 210 J L-1. In conclusion, the energy efficiency can be significantly increased by operating the plasma in a diluted CO2 gas.