Electrochemical exhaust after treatment system
In a project lead by Fuel Cells and Solid State Chemistry Division, in collaboration with Dinex and our research group, an electrochemical exhaust after treatment system is under development. The method is able to remove NOx, soot, CO and un-burnt hydrocarbons in a small scale facility. Our part in the project is to assist with engine experience and experiments in up-scaling and adaption of the system to the real engine application.
Modeling of DPF and DOC for road vehicles
Currently our experience from experiments with DPF’s and DOC’s is used to validate and develop models of complete after treatment system. The models are made in AVL BOOST and AVL FIRE provided by AVL. [Cordtz, R.L. et. al., 2011]
NO to NO2 conversion in exhaust after treatment systems
NOx is the common term for NO and NO2. The current emission regulations for vehicles only restrict the emissions of NOx and therefore treat NO and NO2 evenly. Because NO2 is an effective soot oxidizer many exhaust after treatment system convert NO to NO2 to improve regeneration of the diesel particulate filter (DPF). While the NOx directly from a diesel engine typically contain 20 % NO2, the emission after DPF and DOC may contain up to 70 % NO2 depend on the catalyst.
This has become a growing concern because NO2 is more harmful to humans than NO. The exposure threshold limit values are about 10 times lower. A maximum limit for the air quality of 40 μg/m3, which will be required by the European Union from year 2010 is already exceeded in many city streets.
Haldor Topsoe A/S develops palladium based catalytic coatings for diesel particulate filters that offers efficient soot oxidation without conversion of NO to NO2.
Our research group has a long record of collaboration with Haldor Topsoe A/S about performance testing of their catalytic coatings for diesel particulate filters (DPF) and diesel oxidation catalysts (DOC). Also long term performance of coated DPF’s in taxi fleets has also been tested on our chassis dynamometer. [Johansen, K. et. al., 2008]
Performance testing of DPF and DOC for road vehicles
The research group has a long record of collaboration with Haldor Topsoe A/S, one of the world leading catalyst developers. Our contribution to the collaboration has been performance testing of catalytic coatings for diesel particulate filters (DPF) and diesel oxidation catalysts (DOC) in an engine test stand. Long term performance of coated DPF’s in taxi fleets has also been tested on our chassis dynamometer.
Haldor Topsoe A/S has succeeded with the development and patenting of a palladium based catalytic coating for diesel particulate filters. It offers efficient soot oxidation without conversion of NO to harmful NO2 (link-NO to NO2 conversion in exhaust after treatment systems). Further advantages of the palladium coating compared to conventional platinum coating are better cost efficiency and higher resistance against sulfur. [Johansen, K. et. al., 2008]
Performance testing of DPF for marine diesel generators
The higher sulfur resistance of palladium based catalytic DPF coatings are believed to enable new applications for DPF’s. In a current project the performance of a palladium coated DPF is tested on a 500 kW MAN diesel genset fueled with diesel containing 0.1 % sulfur. This combination of genset and fuel is typically used for electricity generation on container ships in harbor. [Cordtz, R.L. et.al., 2009].
Project partners: Maersk A/S and Haldor Topsoe A/S, AVL, Austria, DTU Risø, DINEX A/S.