Increased diesel vehicle use and growing concerns about the health and environmental effects of exhaust gas pollutants lead to a greater attention upon the reduction of vehicle emissions. The evolution of driving patterns and vehicle technologies lead to lower average exhaust gas temperatures. This can limit the diesel aftertreatment (catalyst) system's ability to meet increasingly stringent emissions legislation. A thermally efficient aftertreatment system can be produced through advanced and novel catalyst designs. The research work presented in this thesis investigates diesel oxidation catalyst (DOC) and exhaust gas properties that can enhance aftertreatment performance at low temperatures. Firstly, an advanced two-catalyst configuration is designed that widens the aftertreatment system operating temperature window. Catalyst cell density, wall thickness and material choices were optimised using theoretical equations, modelling tools and an experimental approach. Secondly, strategics were developed to assist the aftertreatment low temperature activity through the understanding of exhaust species interactions (inhibition and promotion) within the catalyst. This was achieved by varying the exhaust composition at the catalyst inlet, using alternative fuels and combustion modes. Finally, a catalyst component combining a filtration/oxidation function (partial-flow filter) was found to promote particulate removal while reducing the needs for diesel particulate filter active regeneration.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:669094 |
| Date | January 2015 |
| Creators | Lefort, Isaline |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/6299/ |
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