EFFECT OF OXYGEN ON NO_x REMOVAL IN CORONA DISCHARGE FIELD: NO_x BEHAVIOR WITHOUT A REDUCING AGENT

摘要

A DeNO_x process using a DC corona discharge was investigated experimentally. A mixture system of N_2/O_2/NO was used as a test gas. The compositions such as NO, NO_2, N_2O and so on were analyzed with Fourier transform infrared spectroscopy and an NO_2 meter. It was found that the characteristics of NO removal by corona discharge differed remarkably whether or not oxygen exists in the mixture. In regard to the spectrum of light emission from the corona discharge in N_2 atmosphere or N_2/O_2 mixture, some N_2 bands were detected. N_2 dissociation into atomic N and N_2 radical in the corona discharge field was conjectured. Furthermore, ozone was yielded by the corona discharge in the case of the N_2/O_2 mixture. Ozone gas from an ozonizer was added into the N_2/O_2 mixture without corona discharge to investigate the effect of O_3 on the characteristics of NO_x removal by corona discharge. In the case of the N_2/NO mixture, the process of NO reduction was mainly controlled by N_2 radicals excited by the corona discharge. On the other hand, in the case of the N_2/O_2/NO mixture, NO was oxidized by ozone generated from the corona discharge and converted to NO_2 and N_2O_5.