Pulsed Dielectric Barrier Discharges for Gas-Phase Composition Control: A Simulation Model

Featured Application: Control or at least prediction of the gas-phase composition in atmospheric pressure cold plasmas is very important to evaluate the potential of plasma treatments, which could be considered in several applications, from health and environmental processes targeting hazard agents to the production of advanced materials through suitable surface functionalization. We present results obtained from the numerical simulation of the gas-phase chemical kinetics in atmospheric pressure air non-equilibrium plasmas. In particular, we addressed the effect of the pulsed operation mode of a planar dielectric barrier discharge. As conjectured, the large difference in the time scales involved in the fast dissociation of molecules in plasmas and their subsequent reactions to produce stable chemical species makes the presence of a continuously repeated plasma production stage unnecessary and a waste of electrical power and efficiency. The results on NOx remediation, ozone production, water vapor and ammonia dissociation are discussed. A few comparisons with experimental findings in a dielectric barrier discharge reactor already used for applications are also briefly addressed. Our results clearly indicate a pattern for the optimization of the discharge using a carefully designed repetition rate and duty cycle.