Influence of Background Gas for Plasma-Assisted Catalytic Removal of Ethylene in a Modified Dielectric Barrier Discharge-Reactor

The main objective of this work was to investigate the effect of background gas on ethylene removal. Specifically, based on the O₂ content in the background gas, the effectiveness of the system in terms of C₂H₄ abatement and recognition of reaction pathways has been identified. A comparison between packed and non-packed catalysts in a dielectric barrier discharge (DBD) plasma reactor, as well as the behavior of the catalyst-packed system in the absence and presence of water vapor in the feed gas and the effect of shielding the ground electrode with the feed gas have been studied. For the plasma system without the catalyst, the C₂H₄ removal increased with increased specific input energy along with larger toxic byproduct (O₃, NO_x) generation. In the presence of a catalyst, the C₂H₄ removal was enhanced along with lower traces of toxic byproducts due to the availability of active sites for C₂H₄ and reactive species adsorption. The results also revealed that the C₂H₄ removal efficiency was reduced in the presence of water content in the feed gas. Furthermore, C₂H₄ was successfully removed by a modified DBD plasma reactor (the ground electrode was shielded with the feed gas and the reactor was packed with Pd/ZSM-5 catalysts) in which the toxic byproducts formed around the ground electrode passed through the plasma–catalyst zone. Finally, the modified DBD plasma reactor resulted in reduced overall byproducts while maintaining the removal efficiency.