Study of Catalytic Regeneration Mechanisms in Diesel Particulate Filters Using Coupled Reaction-Diffusion Modeling
Diesel particulate filters are today widely accepted as a viable technology for drastically reducing particulate emissions from diesel engines. Current applications are based on some form of catalytic assistance for the filter regeneration purposes, either in the form of a fuel borne catalyst or by employing catalyzed filters. This paper presents an experimental and computational study of the prevailing reaction mechanisms in the catalyst supported DPF systems. The knowledge of the soot reaction kinetics in uncatalyzed filters with O2 and NO2 is a prerequisite in this respect. Next, the reaction rates in the case of using a Ce-based fuel-borne catalyst are evaluated. Emphasis is given on the importance of oxygen diffusion effects during uncontrolled regeneration. Finally, the regeneration mechanisms in a catalyst coated filter are studied.