Lean NOx Trap Regeneration Studies on a Light-Duty Diesel Engine with In-Cylinder Air-to-Fuel Control

James  Parks, Oak Ridge National Laboratory

The efficiency of the regeneration of lean NOx trap catalysts will play a critical role in the feasibility of the technology for diesel engine applications. In-cylinder control of air-to-fuel ratio is one method being investigated for regeneration of lean NOx traps. The reductant chemistry produced during implementation of in-cylinder regeneration will differ depending on injection timing and other strategy details. In the study presented here, a lean NOx trap catalyst is regenerated with different in-cylinder regeneration strategies. The performance of the lean NOx trap for NOx reduction and reductant utilization is characterized. A magnetic sector mass spectrometer was implemented for H2 measurement during regeneration; non-dispersive infrared analyzers were used for measurement of CO. Hydrocarbons were analyzed with FTIR, GC-MS (via bag sampling), and flame ionization detector analyzer techniques. Issues relevant to the regeneration process of lean NOx trap catalysts will be discussed.

Download oral presentation: