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Exhaust gas from diesel engines will be subjected to new and stringent emissions standards. To lower the emissions of carbon particulates (soot), a filtration system has to be fitted in the exhaust line. Diesel Particulate Filters (DPF) trap the soot, which then has to be removed by combustion. Soot doped with cerium-based additives leads to an enhancement of reactivity with O2. It is also well known that the presence of NO2 significantly accelerates the carbon oxidation rate. The CRTTM (Continuous Regeneration Trap) system is based on this property. More recently, the DPNR system (Diesel Particulate NOx Reduction system), which is a DPF impregnated with a NOx trap catalyst, was proposed. The aim of the present study was to investigate the effect of different catalytic materials on soot combustion. Two catalysts were tested: a commercial Oxygen Storage Catalyst (OSC) and a Lean NOx trap catalyst (laboratory made). Different types of soot, both with and without an additive were tested.

Comparisons between 1D simulations and experiments on a mini scale SiC filter are presented. First of all, experiments with regeneration for different loading mass and soot composition enabled us to derive an improved pressure drop correlation. The assumption of constant particulate layer permeability proves unable to predict the influence of the gas temperature on the pressure drop. This discrepancy seems to be linked to the high Knudsen number of the flow in the particulate layer. A new correlation is proposed. This correlation contains four adjustable constants which have been determined on a single experimental run. Without modifying these constants, other cases have been correctly simulated. Obviously, more work is needed to substantiate this approach. In a second step, regenerations with and without additive (Cerium) for two different soot compositions have been simulated and compared with experimental results.