Study on High Voltage Pulse Driven Air Plasma Interaction with NH3 through Direct/Indirect Manner

Removal or reuse of wasted NH3 by cold atmospheric plasma has great potential in industry and green agricultural and is benefit for energy saving and environment protection. This study investigated the interaction between pulse driven air plasma and gaseous NH3 through a direct and an indirect manner. A pin-pin discharge device was used. The gas phase products of direct reaction and indirect reaction of plasma and NH3 were compared and analyzed. It was found that double nitrogen fertilizer NH4NO3 could be formed during the indirect reaction manner while NH3 was decomposed by the direct reaction manner. Fourier transform infrared (FTIR) spectroscopy was used to measure the gas phase products. The concentration of NO, NO2 and NH3 vs. time was calculated to illustrate the chemical process inside the reaction chamber. The optical emission spectrum (OES) of discharging in different gas or gas mixture were recorded and the plasma temperature was fitted by using the spectrum of the N2 second positive system. The steady state temperature profile inside the reaction chamber during the discharge was also simulated. Finally, the possible reactions mechanisms during the direct and indirect reaction process were discussed.