Application of a Three-­‐electrode Plasma Reactor for CO Treatment

F MINOTTI; J.GALLEGO; D. GRONDONA

Conferencia; 16th Latin American Workshop on Plasma Physics LAWPP 2017; 2017

The study on CO elimination has a great importance because it is a very toxic molecule, regarded as one of the most dangerous contaminants [1].In this work, we present a study on a three-electrode plasma reactor to treat CO gas in a N2 atmosphere. The reactor combines a dielectric-barrier discharge (DBD) with a remote, negatively biased third electrode. The DBD is generated by applying an alternating high voltage signal between two circular aluminum flat electrodes attached to opposite sides of a disc made of dielectric material. The third electrode consists in an external cylindrical mesh, coaxial with the DBD electrode system, and fixed to the inner wall of an insulating tube. The air gap between the edge of the DBD electrode system and the mesh electrode is approximately 20 mm wide. The discharge is composed of trains of streamers crossing the air gap through which the gas to be treated flows. Several DBD electrode systems can be connected in parallel along the reactor axis; hence a large plasma volume can be established [2]. The reactor was operated with a gas flow of CO 350 ppm, N2 balanced, and a significant CO removal was observed. CO elimination can be effected either through dissociation by electron impact, or through reactions with reactive species generated by electron collisions. In both cases the necessary energetic electrons are produced in the streamers.