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

Abstract

Abstract This paper studies 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 comprehensively evaluated by a response surface method under different operating parameters (discharge powers, gas flow rate, and initial concentrations) in the DBD plasma system. The results showed that the EY and degradation efficiency could reach 22.17 g kWh−1 and 72.3% when discharge power, initial concentration, and gas flow rate were 5.49 W, 1374.5 ppm, and 529.5 ml min−1, respectively. Furthermore, a mineralization effect was also analyzed related to different operating parameters. When the gas flow rate was 600 ml min−1 and the initial concentration was 2500 ppm, the CO x selectivity could reach 98.5%. Through 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 in the discharge space of the 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.