Correlation of energy efficiency of NO removal by intermittent DBD radical injection method

Ammonia radicals are produced by a dielectric barrier discharge (DBD) in a chamber separate from the chamber that NO gas flows, and are injected in the NO gas flowing field to decompose NO gas. The power source for generating the DBD is a one-cycle sinusoidal (OCS) waveform so as to easily control the power consumed in the DBD plasma. The fundamental frequency of the OCS power source is 150 kHz. The correlation of the DeNOx characteristics was discussed, where the residence time of the ammonia gas in the radical injector and the power density consumed in the DBD plasma were considered. Their product was called residence energy density (RED). It was confirmed that the parametric data of the DeNOx energy efficiency were clearly correlated by the RED. Currently, the energy efficiency of 250 g/kWh was attained at a NO gas temperature of 600°C. In order to obtain a high-energy efficiency in this system, the suppression of the energy consumed in the DBD plasma is effective, and instead, the ammonia flow rate decreases, compensating the accepted energy of the ammonia particles by the residence in the radical injector.