Reduction of NO sub(x) contained in combustion exhaust gas by using corona discharge tube

In order to develop methods of plasma injection for removing pollutants such as NO sub(x) and SO sub(x) contained in combustion exhaust gas, we have investigated radical formation in nitrogen arc plasma, and reported that the NO sub(x) removal efficiency has a maximum value in the range of low electrical power for plasma operated under stable conditions. In this paper, in order to further economize electrical energy in actual use, the simulated exhaust gas (N sub(2) + O sub(2) + CO sub(2) + NO) is excited by passing through a corona discharge tube in a high electric voltage field. The NO is oxidized to NO sub(2), and OH radical generated from H sub(2)O contained in gas reacts with NO sub(2), and NO concentration decreases as a result of generation of HNO sub(3). The effects of H sub(2)O, O sub(2) and CO sub(2) contents on the NO sub(x) reduction rate are discussed experimentally. The NO sub(x) reduction rate of about 25% is obtained under the input power of 45 watts.