Reduction of Nitric Oxide in Flue Gases by Point to Plane Corona Discharge with Catalytical Coatings on the Plane Electrode

Abstract

Abstract A corona discharge with catalytical coatings on its plane electrodes has been studied as a technique for NOx reduction in gas mixtures. The underlying concept is that the combination of a gas discharge with calalytically active electrode coatings may allow the activation of the thermodynamically favourable NO-decay, e.g. into the 2NO → N2 + 02 reaction channel. Widely differing materials such as metal oxide catalysts, conductive polymers, Si3N4-passivation and nitro enamon were tested as electrode coatings. With given corona polarity the different coatings gave widely differing DeNOx-efficiencies, the values of which are distributed over an interval of about two orders of magnitude. The largest energy yield this far obtained is 4mg of reduced NO per dissipated kilojoule of electrical energy. Further experiments will aim at improving this value by a factor of five at least, so that a typical coal power plant‚s flue gas could be cleaned of its NO from, for example, 1200 ppm to 200 ppm by employing ...