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 % NH
3
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 N
2
. 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.