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NOx Control Development with Urea SCR on a Diesel Passenger Car
Technical Paper
2004-01-1291
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
Diesel vehicles have significant advantages over their gasoline counterparts including a more efficient engine, higher fuel economy, and lower emissions of HC, CO, and CO2. However, NOx control is more difficult on a diesel because of the high O2 concentration in the exhaust, making conventional three-way catalysts ineffective. Two current available technologies for continuous NOx reduction onboard diesel vehicles are Selective Catalytic Reduction (SCR) using aqueous urea and lean NOx trap (LNT) catalysts. This paper discusses an application with SCR. SCR with ammonia has been used for many years at stationary sources. Aqueous urea is a convenient way to deliver ammonia onboard a vehicle and high NOx efficiencies have been shown in past work by Ford and others using urea.
Tailpipe NOx emissions from a modified European production level 1.8L diesel Ford Focus TDCi were reduced to the range of ULEVII levels (0.05 g/mi NOx) with a green catalyst system. The green system also had results within the Tier 2 SFTP US06 standard (0.14 g/mi NMHC+NOx). An oxidation catalyst was used to convert engine-out HC and CO upstream of the urea SCR system. Aqueous urea was added to the exhaust using a Ford-developed air-assisted injection system. A base metal/zeolite SCR catalyst utilized the added reductant to convert NOx to N2 under lean conditions.
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Citation
Tennison, P., Lambert, C., and Levin, M., "NOx Control Development with Urea SCR on a Diesel Passenger Car," SAE Technical Paper 2004-01-1291, 2004, https://doi.org/10.4271/2004-01-1291.Also In
Diesel Emissions on CD-ROM from the SAE 2004 World Congress
Number: SP-1835CD; Published: 2004-03-08
Number: SP-1835CD; Published: 2004-03-08
References
- Heck R.M. Farrauto R.J. “Catalytic Air Pollution Control,” Van Nostrand Reinhold New York 1995
- Luders H. Backes R. Huthwohl G. Ketcher D.A. Horrocks R.W. Hurley R.G. Hammerle R.H. “An urea lean NOx catalyst system for light duty diesel vehicles,” SAE 952493
- Held W. Konig A. Richter T. Puppe L. “Catalytic NOx reduction in net oxidizing exhaust gas,” SAE 900496
- Miller W.R. Klein J.T. Mueller R. Doelling W. Zuerbig J. “The development of urea-SCR technology for US heavy duty trucks,” SAE 2000-01-0190
- Mueller W. Ölschlegel H. Schäfer A. Hakim N. Binder K. “Selective Catalytic Reduction - Europe's NOx Reduction Technology” SAE 2003-01-2304
- “Selective Catalytic Reduction (SCR) Infrastructure Study” Project Review Meeting Little Arthur D. October 1 2001
- Jackson M.D. Fable S. Venkatesh S. “Viability of Urea Infrastructure for SCR Systems” TIAX, LLC, U.S. Environmental Protection Agency Clean Diesel Engine Implementation Workshop Chicago, Illinois August 6-7 2003
- Fable S. Venkatesh S. “Development of a Urea Infrastructure to Support MY2007+ Heavy-duty Vehicle Emission Requirements”
- Baker D. Hammerle B. Backes R. Aachen, Ger. October 2000
- Levin M.B. Baker R.E. “Co-fueling of Urea for Diesel Cars and Trucks” SAE 2002-01-0290
- Hug H.T. Mayer A. Hartenstein A. “Off-highway exhaust gas after-treatment combining urea-SCR, oxidation catalysis and traps,” SAE 930363
- Koebel M. Elsener M. Marti T. “NOx-Reduction in diesel exhaust gas with urea and selective catalytic reduction,” Combust. Sci. and Tech. 121 1996 85 102
- Lambert C. Montreuil C. Vanderslice J. “Application of Organic Freeze-point Depressants in Aqueous Urea Solutions: Effect on NOx Reduction,” SAE 2003-01-0775
- Hughes R. “Deactivation of Catalysts,” Academic Press New York 1984