NO Dissociation Process Of Pulse Discharge In N₂ Environment

As the main atmosphere pollutant, NO is great harm to human health. As people's awareness of environmental protection increases, NO Dissociation Technology, which is reasonable in economy and feasible in technology, becomes an important mathod of NO controlling. In this paper, NO is studied by dispersed fluorescence spectra in two kinds of pulsed streamer discharge mode. Meanwhile, the kinetics process of NO dissociation is investigated.With this Ar emission spectra,first, N2 plasma characteristics in pulse streamer discharge at atmospheric pressure is studied by using trace Ar dispersion fluorescence spectrometry method. Ar atomic fluorescence spectra are assigned, and then plasma electron excited temperatures are obtained using relative fluorescence intensity ratio method and Boltzmann plot method and Fermi– Dirac distribution model, respectively. The calculated plasma electron excited temperature from Boltzmann plot method is 7474±500 K, which is nearly equal to the one from Fermi– Dirac distribution model ,7480±500K. This fact shows that the atmospheric plasma by pulse streamer discharge is approximate in the state of local thermodynamic equilibrium(LTE) .Second, the kinetics process of NO dissociation is investigated by comparing the dispersed fluorescence spectra of only NO and NO in N2 at two kinds of discharge mode: negtive pulsed discharge and dielectric barrier discharge. The result shows that: in the former discharge mode, the mainly process of NO dissociation is that NO is discomposed into excited atoms N and O, and than N combine with each orther forming excited species N2, while the atoms O fromed excited species O2; After joining the N2 did not find changes in the product particles. in the latter discharge mode, the NO molecules which become NO+, firstly ourred inelastic collisions with high-enegy electrons, secondly NO+ dissociated into N+ and O, and then N+ combine with the electron forming the excited atoms N, finally N combine with each orther forming excited species N2, while the atoms O fromed O2. After joining the N2 did not find changes in the product particles too. Thus, the kinetics process of NO dissociation is different in the two kinds of dischage mode, and they are two different reaction channels. Join N2 does not change the main dissociation channel of NO.CO is also the main product of the combustion process. The impact of CO in this experiment is examined on NO removal. With the additive CO in two types of discharge mode: negtive pulsed discharge and dielectric barrier discharge, O atomic fluorescence spectral lines significantly decreased or even disappeared.It is show that CO captured the O atoms in NO dissociation,so add CO gas is conducive to NO removal.