Browse Publications Technical Papers 2004-01-0696

Reaction and Diffusion Phenomena in Catalyzed Diesel Particulate Filters 2004-01-0696

The objective of this study is to explain the physical and chemical mechanisms involved in the operation of a catalyzed diesel particulate filter. The study emphasizes on the coupling between reaction and diffusion phenomena (with emphasis on NO2 “back-diffusion”), based on modeling and experimental data obtained on the engine dynamometer. The study is facilitated by a novel multi-dimensional mathematical model able to predict both reaction and diffusion phenomena in the filter channels and through the soot layer and wall. The model is thus able to predict the species concentration gradients in the inlet/outlet channels, in the soot layer and wall, taking into account the effect of NO2 back diffusion. The model is validated versus engine dyno measurements. Two sets of measurements are employed corresponding to low-temperature “controlled” regenerations as well as high-temperature “uncontrolled” conditions. Good agreement is observed between measured and computed results in both regeneration modes. It is concluded that at low temperatures, the main reaction mechanism involves NO2 produced on the catalytic sites and partially diffusing back to the soot layer (re-cycling). At high temperature regeneration modes, NO2 is not favored due to chemical equilibrium limitations and therefore the main reaction path involves oxygen reaction with soot.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 17% off list price.
Login to see discount.
Special Offer: Download multiple Technical Papers each year? TechSelect is a cost-effective subscription option to select and download 12-100 full-text Technical Papers per year. Find more information here.
We also recommend:

Modeling and Experimental Study of Uncontrolled Regenerations in SiC Filters with Fuel Borne Catalyst


View Details


Microstructural Aspects of Soot Oxidation in Diesel Particulate Filters


View Details


Validation of a Model and Development of a Simulator for Predicting the Pressure Drop of Diesel Particulate Filters


View Details