NOx Removal Using Discharge Plasma and Electrophoresis

A NOx (a general term describing the sum of NO and NO₂) removal process for diesel exhaust has been investigated. NO was oxidized to NO₂ and HNO₃ using the pulsed discharge plasma, and then was adsorbed to the adsorption cell. Electrophoresis was made in the adsorption cell to maintain the adsorbing ability. In the NOx oxidation process, about 60% to 80% of NO was oxidized to NO₂ and HNO₃ by the pulsed discharge plasma with the specific input energy of 45J/L. 95% of NO₂ and HNO₃ was adsorbed by the gamma alumina adsorption cell. When a DC voltage was applied to the absorption cell, nitrate ions were driven to the anode, and the sodium ions were concentrated to the cathode side. The absorbing ability was maintained when the electrophoresis was conducted. A molecular sieves 13X were also studied as the adsorbent in this study.