NOx removal using ammonia radicals prepared by intermittent dielectric barrier discharge in atmospheric pressure

The NOx removal was made at a temperature of 950°C by using ammonia radicals. The radicals were efficiently produced by flowing 1–3 % NH3 in Ar through the dielectric barrier discharge of a one-cycle sinusoidal (OCS)-wave power source. The discharge was intermittently made between coaxial cylindrical electrodes with a space of 1.5 mm at an applied peak-to-peak voltage of 10–35 kV. At the mixing zone in the reaction chamber the spectrum of the NH radical was observed at 336.7 nm. The radicals were introduced to a reaction chamber, and were mixed with 1000 ppm NOx in N2. The NOx reduction increased with increasing the concentration of the NH radical. The dependence of NOx reduction on the duty cycle of OCS voltage was also discussed.