The effect of O₂ in a humid O₂/N₂/NO_x gas mixture on NO_x and N₂O remediation by an atmospheric pressure dielectric barrier discharge

A numerical model for N_xO_y remediation in humid air plasma produced with a dielectric barrier discharge at atmospheric pressure is presented. Special emphasis is given to NO₂ and N₂O reduction with the decrease of O₂ content in the feedstock gas. A detailed reaction mechanism including electronic and ionic processes, as well as the contribution of radicals and excited atomic/molecular species is proposed. The temporal evolution of the densities of NO, NO₂ and N₂O species, and some other by-products, is analyzed, and the major pathways for the N_xO_y remediation are discussed for one pulse. Subsequently, simulations are presented for a multi-pulses case, where three O₂ contents are tested for optimization of the remediation process. It is found that when the gas mixture O₂/N₂/H₂O/NO^x has no initial O₂ content, the best NO_x and N₂O remediation is achieved.