NOx removal by non-thermal plasma reduction: experimental and theoretical investigations

Green and efficient NOx removal at low temperature is still desired. NOx removal via non-thermal plasma (NTP) reduction is one of such technique. This work presents the experimental and theoretical study on the NOx removal via NTP reduction (NTPRD) in dielectric barrier discharge reactor (DBD). The effect of O-2 molar fraction on NOx species in the outlet of DBD, and effects of NH3/NO molar ratio and discharge power of DBD on NOx removal efficiency are investigated. Results indicate that anaerobic condition and higher discharge power is beneficial to direct removal of NOx, and the NOx removal efficiency can be up to 98.5% under the optimal operating conditions. It is also found that adding NH3 is favorable for the reduction of NOx to N-2 at lower discharge power. In addition, the NOx removal mechanism and energy consumption analysis for the NTPRD process are also studied. It is found that the reduced active species (N*, N-, N+, N-2*, NH2+, etc.) generated in the NTPRD process play important roles for the reduction of NOx to N-2. Our work paves a novel pathway for NOx removal from anaerobic gas in industrial application.

Automated summary

This study investigates the removal of NOx via non-thermal plasma reduction in a dielectric barrier discharge reactor. The results show that anaerobic conditions and higher discharge power contribute to a direct removal of NOx, with a maximum removal efficiency of up to 98.5% under optimized conditions. Adding NH3 favors the reduction of NOx to N-2 at lower discharge power. The study also reveals the role of reduced active species in the NOx removal mechanism during the non-thermal plasma reduction process.