A Concept of Plasma Assisted Catalyst System Using a DeNOx Catalyst for an Automobile Diesel Engine 2004-01-1834
Through the basic research of the plasma assisted catalyst system using DeNOx catalysts and the gas analysis of the system, its conceptual use for automobile diesel engine applications has been studied. This study has shown that the length between the plasma reactor and the catalyst reactor does not affect the NOx conversion. To obtain an efficient NOx conversion, the plasma should affect both the HC as the reductant and NOx at the same time. In the case of γ-Al2O3 and C3H6, the main component for NOx reduction was CH3CHO generated by the plasma. Under 250 deg. C, the temperature was too low for the γ-Al2O3 to become effective. Therefore, the NOx conversion became low. At 400 deg. C, the NOx conversion became high. However, at 600 deg. C, the CH3CHO for reducing NOx was not generated, and the NOx conversion decreased. By using multi-catalysts (Na-ZSM-5, In/Al2O3 and Pt/Al2O3), an efficient NOx conversion was obtained under the transient gas temperature conditions similar to those of the automobile exhaust.