NO Removal using Multipoint-to-plane DBD Ozone Injector

Abstract

This paper describes an improvement of NO removal efficiency using dielectric barrier discharge (DBD) ozone injection system, with focusing comparison with a conventional plasma remediation system and effect of electrode configuration employed in the DBD reactor. Ozone was generated in the DBD reactor, and was fed to an oxidizing chamber to convert NO into NO2. The experiments were carried out with applying sinusoidal voltage of 10 kHz. Nitrogen, oxygen, and NO gas with concentration of several hundreds ppm was used as simulated gas of a diesel engine exhaust gas. For ozone injection system, we obtained the 18-g/kWh energy yield close to well-known 20 g/kWh. However, for the conventional plasma remediation system, we obtained the 10-g/kWh energy yield lower than well-optimized DBD reactor. Under well-optimized conditions, there was little difference in energy yield between the ozone injection system and the conventional plasma remediation system. On the other hand, the ozone injection system was also effective under unoptimized conditions. The electric fields of the needle-type electrodes were strongly distorted in spatial distribution, as a result, it caused the low-voltage operation and the dielectric loss compared with the plane electrode. The pyramid projection height was not dominant factor for the DBD reactor performance.