An Urea Lean NOx Catalyst System for Light Duty Diesel Vehicles 952493
Future European air quality standards for light duty diesel vehicles will include stringent NOx emission regulations. In order to meet these regulations, a lean NOx catalyst system may be necessary. Since the catalytic removal of NOx is very difficult with the large concentration of oxygen present in diesel exhaust, a reductant is usually added to the exhaust to increase the NOx conversion. This paper describes a lean NOx catalyst system for a Transit light-duty truck which uses a reductant solution of urea in water.
In this work, a microprocessor was used to vary the amount of the reductant injected depending on the operating conditions of a 2,5 L naturally aspirated HSDI engine. The NOx conversions were 60% and 80% on the current European driving cycle and the U.S. FTP cycles, respectively. Data on the emissions of HC, CO, NOx, particulate mass and composition, individual HC species, aldehydes, PAH and most HC species were evaluated. No detectable levels of ammonia were emitted when the catalyst volume was optimized. The average consumption of the urea-water solution was 2,5 cc/km. Problems associated with supplying sufficient urea-water solution over the life of the vehicle are discussed.
Citation: Lüders, H., Backes, R., Hüthwohl, G., Ketcher, D. et al., "An Urea Lean NOx Catalyst System for Light Duty Diesel Vehicles," SAE Technical Paper 952493, 1995, https://doi.org/10.4271/952493. Download Citation
Author(s):
H. Lüders, R. Backes, G. Hüthwohl, D. A. Ketcher, R. W. Horrocks, R. G. Hurley, R. H. Hammerle
Affiliated:
FEV Motorentechnik, Ford Motor Co.
Pages: 15
Event:
1995 SAE International Fall Fuels and Lubricants Meeting and Exhibition
ISSN:
0148-7191
e-ISSN:
2688-3627
Related Topics:
Air pollution
Environmental regulations and standards
Diesel exhaust emissions
Quality standards
Catalysts
Water
Nitrogen oxides
Particulate matter (PM)
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