DPF systems comparison -: Fuel borne catalyst or catalysed particulate filter for diesel passenger cars?

The German Automobile industry has announced to fit at least a part of their Diesel models with particulate filters by the beginning of next year (2004). In contrast to the PSA concept, which is dependent on fuel additives to support the regeneration, the concept which most of the German car manufacturer want to launch on the market operates without additives. The innovative system they rely on needs a catalysed soot filter. The content of this paper is the technical comparison of both concepts with regard to exhaust backpressure, regeneration behaviour, packaging and resulting from this, fuel consumption and operating cost. In this comparison the fuel borne catalyst has clear technical advantages. A severe disadvantage is however the additional ash from the FBC fill up the filter earlier leading to reduced service interval. This issue can be solved using a bigger filter or using a new filter geometry. Using P-CAT, a calculation tool developed by Tenneco Automotive, it is possible to show that the back pressure targets of about 250000 km (useful life) set by the car manufacturers can be met with both systems. On one hand, the fuel additives have been optimised, which permitted a reduction in the dosage and thereby reduced ash production. On the other hand, a new generation of filters have been developed with optimised ash storage capacity.