Abstract
To broaden and lower the narrow temperature window of the selective non catalytic reduction (SNCR) of nitric oxide (NO), the use of activated ammonia as the reduction agent was examined A xenon excimer lamp emitting a wavelength of 172 nm (i.e., vacuum ultraviolet; VUV) was employed as the excitation source for molecular ammonia. The effects of reaction temperatures, oxygen concentrations, and NH_3/NO molar ratios (MRs) on NO removal were investigated in a lab-scale plug flow reactor. Temperatures ranged from 500℃ to 850℃. A temperature window enlargement of 150℃ was achieved at the lower boundary of the temperature window. Above 600℃, NO removal was effected by injection of activated ammonia, while around 750℃, conventional SNCR by injection of molecular ammonia was effective. An approximate 80% NO removal was attained at 700℃ with an MR=2.0 and 8.3% O_2.
