Investigation of high-concentration toluene degradation by DBD plasma under different operating parameters

Abstract

This paper studied the degradation effect of high- concentration toluene in dielectric barrier discharge (DBD) plasma under different operating conditions. The degradation efficiency and energy yield (EY) were comprehensive evaluated by response surface method (RSM) under different operating parameters (discharge powers, gas flow rate, and initial concentrations) in the DBD plasma system. The results showed that EY and the degradation efficiency could reach 22.17 g/kWh and 72.3% when discharge power, initial concentration, and gas flow rate were 5.49 W, 1374.5 ppm, and 529.5 mL/min, respectively. Besides, mineralization effect was also analyzed related to different operating parameters. When the gas flow rate was 600mL/min and the initial concentration was 2500 ppm, the COx selectivity could reach 98.5%. Through the analysis of the effect of oxygen content in the background gas on high-concentration toluene degradation, it was found that oxygen content had a significant effect on the formation of oxygen-containing active substances. Emission spectra showed that normal air discharge occurred at the discharge space of DBD plasma, and nitrogen-containing active substances were generated. Therefore, active substances containing oxygen and nitrogen played an important role in DBD plasma degradation of high-concentration toluene.