Abstract
Continuous operation tests of the boiler emission treatment plant which consists of a commercial ozonizer for indirect NO oxidation and a Na_2SO_3 chemical scrubber are carried out for gas firing and heavy oil boilers. For gas firing boiler emission, the NO complete removal and the decrease in NO_x from 32 ppm to 3 ppm are achieved. This performance is maintained for 300 min by keeping -30 mV of oxidation-reduction potential (ORP) of circulating solution in the chemical scrubber. Concerning the treatment of heavy oil boiler emission, the decrease in NO_x from 90 ppm to less than 25 ppm is maintained for 250 min by keeping -30 mV of ORP. However, the unreacted NO of 15 ppm is detected at a scrubber outlet because the O_3 for NO oxidation is inadequate. By sufficient O_3 injection for NO oxidation, NO_x removal efficiency can be improved.
