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

NOx removal was carried out at a temperature of 600 degreesC using ammonia radicals, which were generated by flowing NH3 gas diluted with Ar gas through the dielectric barrier discharge with a one-cycle sinusoidal-wave power source. The discharge was intermittently formed between coaxial cylindrical electrodes with a space of 1.5 mm at an applied peak-to-peak voltage of 5-18 kV. The radicals were introduced in a reaction chamber and mixed with NO gas, which was diluted with N-2 The dependence on the discharge power was measured by varying the repetition rate and applied voltage. The NO reductions at various flow rates and concentrations of NO gas could be expressed as a constant volumetric NO reduction rate. There was an optimum discharge power and an optimum mean residence time of NH3 gas for effective NO reduction.