Investigation on luminescence and NOx removal by pulse corona discharges

In a streamer dominated pulse corona the energetic electrons can interact w ith the gas molecules and produce radicals. Emission of second positive ban d (SPB) of the nitrogen, which was considered to correspond to local yield of N radical, was monitored in this study for analyzing N radical effect on removal of nitrogen oxides (NOx) from exhaust gases. It was found that the length of high luminous region (HLR) is related to energy efficiency of NO , removal. It was also testified that total emission intensity of SPB is li nearly proportional with NOx removal in NO/N-2 mixture gas. Analysis of exp erimental data shows that the NOx removal energy efficiency is smaller when pulse width is longer. The energy efficiency also decreases with the incre ase of injected power and length of HLR, respectively. It was assumed that the local concentrated production of N radical in HLR is not effectively us ed for NO removal in the condition of low initial NOx concentration. It is concluded that the luminescence analysis provides a good method to understa nd NOx removal process in pulse discharge corona. (C) 2001 Elsevier Science B.V. All rights reserved.