Measurement and discharge-chemical kinetics calculation of radicals density at low-pressure discharge denitrification

Appearance Mass Spectroscopy, Radical Density, Low-Pressure, Discharge Denitrification Abstract: In a discharge denitrification process where discharge electrons collide with combustion gas to produce N, O, OH and II radicals, the produced radical is said to be a key factor which decides the denitrification performance through the oxidization and/or the reduction of NO_x. In this study N, O, OH and H radical densities have been measured by the appearance mass spectrometry in a low-pressure discharge tube in which the simulated combustion gas flows. The radical densities of about 10¹¹ -10 ¹² cm^-3 have been measured at the outside of cathode fall region when the s-n ratio is high. Boltzmann's equation for the electron energy distribution function has been solved numerically under conditions of the measured electric field and the experimental gas composition, and the denitrification chemical reactions have been calculated kinetically including the produced radical densities. The measured radical densities agree well with the analytical which correspond to the same electron density as the measured by the Langmuir probe.