REDUCTION OF NITRIC-OXIDE IN FLUE-GASES BY POINT TO PLANE CORONA DISCHARGE WITH CATALYTIC COATINGS ON THE PLANE ELECTRODE

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 catalytically active electrode coatings may allow the activation of the thermodynamically favourable NO-decay, e.g. into the 2NO →N2 + O2 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 4 mg 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 about 5% of its electrical power. © 1990, Taylor & Francis Group, LLC. All rights reserved.