Emission spectrometry of microplasma for NOx removal process

Emission spectra of the microplasma discharge in N2, NO and O2 gas mixture was analyzed. The diagnosis of microplasma discharge was performed in order to understand the processes of NOx removal. An experimental Marx Generator was used as a pulsed power supply. Emission spectra for N2 gas show N2 second positive band system (N2 SPS) and N2 first negative band system (N2 FNS). 1000 ppm NO in N2 emission spectra shows N2 SPS, N2 FNS and NO γ band. 950 ppm NO and 5% O2 in N2 gas emission spectrum shows N2 SPS and N2 FNS with lower intensities comparing with microplasma discharge in N2 gas. Emission signal of the photomultiplier, show short lifetime emission signal for N2 SPS of 337.1 nm. Lifetime of emission signal is longer (2μs) than that of N2 SPS due to the excitation by the collision of N2 metastable states. Temperature measurements are also carried out, which show the temperatures are specific for non-equilibrium plasmas.