Flue gas treatment using dielectric barrier discharge with multipoint electrode

Abstract

An experimental study on NOx removal from a simulated diesel engine exhaust gas was carried out using dielectric barrier discharge (DBD) reactor for various electrode shapes to improve the removal efficiency. The electrode shapes employed in the experiment were a plane, a trench and a multipoint configurations. The right-pyramid, which was employed as multipoint, had 45/spl deg/ tip angle and a height of 5 mm. The multipoint electrodes have 528 to 5000 pyramids in an area of 132 cm/sup 2/ (6 cm x 22 cm). The trench one has knife-edge rails with 5 mm height and 45/spl deg/ tip angle. The 0.5 mm thickness of alumina (Al/sub 2/O/sub 3/) dielectric barrier was produced on a plane electrode via a powder flame spray. NO removal yield drastically decreases with increasing pyramids number on the electrode. NO removals in case of the plane and the trench electrodes were lower than that in case of the multipoint electrode. The DBD reactor with the multipoints electrodes was applied to 20 kVA diesel engine generator exhaust gas treatment. The contained NOx (NO+NO/sub 2/) is abated from 70 to 40 ppm at no-load to the generator, and from 340 to 300 ppm at 50 A load. The energy cost for the NOx removal is obtained to 32 g/kWh.