Comparison of single and double dielectric barrier discharge non-thermal plasma for toluene removal

In order to investigate the effect of dielectric barrier discharge (DBD) reactor structure on toluene degradation in non-thermal plasma, reactors with single and double barrier were designed. The discharge characteristics, toluene removal efficiency, mineralization rate, CO2 selectivity and energy efficiency of the two rectors were compared, and the effects of voltage and initial concentration on toluene degradation were analyzed. The results indicated that DDBD reactor had higher electric field strength and SDBD reactor had higher power under the same applied voltage. The removal efficiency of toluene in the DDBD reactor ranged from 9.4%~100%, 7.4%~99%, 5.1%~64% and that in the SDBD reactor ranged from 67%~98%, 46%~90%, 26%~59%, when the initial toluene concentration and the applied voltage were 616, 1 027, 1 848 mg·m−3 and were 14~24 kV, respectively. It showed that SDBD has a higher toluene removal efficiency at low applied voltage, while the removal efficiency is higher in DDBD at a higher applied voltage. Moreover, the decrease of toluene concentration and the increase of applied voltage were favorable for toluene degradation. In SDBD, the energy efficiency decreased with the increase of applied voltage, while that of the DDBD reactor first increased and then decreased. The energy efficiency of the DDBD reactor was higher than that of the SDBD reactor at 16~24 kV. The present study could provide reference for the application of DBD in VOCs abatement.