Pulsed electrical discharges assisted by dielectric pellets/catalysts for diesel engine exhaust treatment

This paper reports the study on gaseous pollutants (NOx, CO and HCs) using a combination of electric discharge plasma and catalysts. In this study, catalysts being used in conventional catalytic converters of gasoline engine were tried, for the first time, in diesel engine exhaust treatment assisted by electric discharge plasma. Initial studies investigate the effect of packed dielectric materials and catalysts on NOx removal. Both conventional and non-conventional catalysts were used in the studies. With plasma alone, the removal efficiency of oxides of nitrogen was around 75% and with a suitable combination of catalytic reactor the removal efficiency was as high as 90%. Among the catalysts studied, a new catalyst (CuMnAlO₄) was found to be as effective as the conventional expensive catalyst. The formation of byproducts like N₂O and HNO₃ have been studied and the results are discussed.