4-way Catalyst Modeling in Wall-Flow and Deep-bed Substrates

Grigorios  Koltsakis, Aristotle University Thessaloniki

Due to the increasing pressures to develop small-size and low-cost after-treatment systems meeting the legislative demands it is desirable to integrate multiple functionalities in a single package. The catalyzed wall-flow particulate filter is a suitable reactor for this purpose. The well-known DPNR system targets 4-way catalysis by using appropriate NOx trapping catalytic components and sophisticated engine calibraion. The integration of SCR-based de-NOx functionality on a wall-flow reactor is also conceivable. In the present work, an extended 3-dimensional modeling tool capable of treating 4-way wall-flow catalysts will be presented. This is accomplished by integrating NOx storage/release and SCR reaction schemes in the existing coupled transport-reaction model developed by LAT/AUTh in the past. Representative simulation results and comparisons with experimental data will be presented. In addition, 4-way diesel after-treatment may be accomplished by deep-bed reactors, e.g based on foam substrates. The presentation will also deal with the simulation of foam based 4-way catalysts, illustrating the progress of multi-dimensional filtration, transport/reaction modeling in this area. The foam model is also calibrated and validated against extensive experimental data. Both 4-way catalyst models are readily integratable in a complete exhaust line simulation platform supporting the design and control of modern diesel after-treatment systems.

Download Presentation: