Modeling of Wall-flow Particulate Filters with Catalyst Zoning
Grigorios Koltsakis, Aristotle University Thessaloniki
Catalyzed wall-flow particulate filters are increasingly applied in diesel exhaust after-treatment. Apart from facilitating low-temperature catalytic regeneration, the catalytic coating may assist CO and hydrocarbon conversion, as well as exothermic heat generation during forced regeneration conditions, especially in single-brick systems.
The need for cost reduction necessitates optimum exploitation of the precious metal catalysts applied in the filter. In this respect, a promising approach is to apply the coating in part of the DPF, a technology referred to as “catalyst zoning”. To simulate the behavior of such a filter, one has to take into account the complex interactions between the reaction and mass-transport phenomena in the DPF channel together with the effects of non-uniform wall permeability. The coupled transport-reaction model of LAT/AUTh already developed and published in 2004 is applied in this work to study the potential of catalyst zoning as regards pressure drop effects, low-temperature regeneration and post-injection conditions.