Jerks-and-jumps type electrode diagnostics in a DBD reactor by OES

Abstract

This work reports on the successful measurement of the second-positive N2(B − C) and the first-negative N +2 (B − X) band system emissions intensities for the transitions observed in the 337.1-and 391.4-nm wavelengths, respectively, by optical emission spectroscopy (OES). By determining the electron energy distribution function and the spectroscopy results, it is possible to obtain the average electron energy of the system. Two dielectric barrier discharge reactors of rectangular geometry have been used for this purpose: a first reactor, endowed with a single dielectric and a modified electrode, in which discontinuities of the jerks-and-jumps type were manufactured in order to confine the discharge, and a second reactor of conventional flat electrodes and a double dielectric. The final objective of this study is to ascertain which of the reactors provides a higher efficiency in the NO x removal from a gas mixture. The results indicate that, for the first reactor, energies on the order of 11 eV were reached, while lower energies up to 8 eV were obtained in the second reactor. This indicates clearly that the first reactor is close to the corona discharge behavior. As to the removal efficiency, the first reactor showed a better performance with inferior concentrations around a 50-μmol/mol mixture.