Ceramic DPF (diesel particle filter) are a great success from the point of view of ceramists; comparable to the oxidation catalyst carrier business. The number and variety will increase tremendously until 2014. The next future for car equipment will see a competition for the cheapest way to produce filters and materials which will stand the further optimized (lower) stresses during application. Most of the concepts use precious metal catalyst coatings which are by far more expensive than the filter itself. The price of platinum has tripled since 2001 to about 30 EUR/g (2007). A typical CDPF is coated with 3-4 g per liter filter. Therefore, concepts requiring only very low amounts of precious metals have to be focused. It is another question, how changing fuel quality will effect the emissions and the regeneration of the filters. A technical and commercial problem is the retrofit of older engines, which will be very much limited for the next 2-3 years, but for heavier engines, e.g. in busses or construction machines, this will be a long lasting business. A real challenge is a filter system with a reliably and continuously working regeneration, if possible combined with a DeNOx system. Currently a general shift to R&D for DeNOx systems can be observed, driven by the future emission limits. Main topics are the well known TiO2 supported V2O5 catalysts, used as honeycomb monoliths or coated on cordierite substrates; alternatively Cu/Fe-zeolithes are addressed for SCR. NOx storage traps need to be more robust. Pretreatment or aftertreatment devices for desulphurization, de-NH3 or de-NO2 will be necessary for some configurations. The introduction of particulate number limits in EURO 6/IV can cause a redesign of some filter strategies, although most of the current wall flow filter systems reach the proposed limit of 1011 particles/km. It is much more interesting that direct injection gasoline cars are producing measurable amounts of particulate emissions, well below the EURO 4 diesel emissions limit, but higher than trap-equipped diesel cars. Despite the success of the aftertreatment technologies, research for cleaner combustion like HDDI or other efficient energy sources like hydrogen will change this world completely in the long term range.
Ceramic diesel particulate filters - status and trends
2008
10 Seiten, 1 Bild, 36 Quellen
(nicht paginiert)
Aufsatz (Konferenz)
Englisch
Kraftfahrwesen | 2003
|Optimized Regeneration Conditions of Ceramic Honeycomb Diesel Particulate Filters
SAE Technical Papers | 1983
|Thermal durability of wall-flow ceramic diesel particulate filters
Kraftfahrwesen | 2001
|Thermal Durability of Wall-Flow Ceramic Diesel Particulate Filters
British Library Conference Proceedings | 2001
|Optimized Regeneration Conditions of Ceramic Honeycomb Diesel Particulate Filters
Kraftfahrwesen | 1983
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