Comparison of electrical discharge techniques for nonthermal plasma processing of NO in N/sub 2/

Abstract

This paper presents a comparative assessment of three types of electrical discharge reactors: 1) pulsed corona, 2) dielectric-barrier discharge, and 3) dielectric-pellet bed reactor. The emphasis is on the efficiency for electron-impact dissociation of N/sub 2/(e+N/sub 2//spl rarr/e+N+N) and the subsequent chemical reduction of NO by nitrogen atoms (N+NO/spl rarr/N/sub 2/+O). By measuring the concentration of NO as a function of input energy density in dilute mixtures of NO in N/sub 2/, it is possible to determine the specific energy cost for the dissociation of N/sub 2/. Our experimental results show that the specific energy consumption (eV per NO molecule reduced) of different types of electrical discharge reactors are all similar. These results imply that, during radical production in electrical discharge reactors, the electric field experienced by the plasma is space-charge shielded to approximately the same value. The specific energy consumption for the dissociation of N/sub 2/ using electrical discharge processing is measured to be around 240 eV per nitrogen atom produced. In the NO-N/sub 2/ mixture, this corresponds to a specific energy consumption of around 240 eV per NO molecule reduced.