This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Laboratory and Engine Study of Urea-Related Deposits in Diesel Urea-SCR After-Treatment Systems
Technical Paper
2007-01-1582
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Diesel exhaust systems equipped with selective catalytic reduction (SCR) catalysts based on urea were subjected to an aging process where the exhaust gas temperature was below 300°C. Solid deposits related to urea injection were found on the wall of the exhaust pipe down stream of the urea injector and on a urea mixer in front of the SCR catalyst. In laboratory tests, an aqueous solution of urea (1.5wt%) was dripped onto an SCR catalyst core in a simulated lean gas mixture at a rate corresponding to a 1:1 NH3-to-NOx ratio (NOx = 350ppm) and a space velocity (SV) of 15,000 h-1 at various temperatures. At 300°C and below, urea-related deposits appeared on the SCR catalyst surface and totally plugged the SCR catalyst monolith within 250 hours. When the aging temperature was 350°C or above, no deposits were observed on the SCR catalyst core. The deposits from engine dynamometer and laboratory aging experiments were found to be similar, based on analyses by FTIR spectroscopy and powder X-ray diffraction. Thermal gravimetric analysis (TGA) demonstrated that most of the deposits vaporized at temperatures between 310 to 325°C when heated slowly, although the deposits did not vaporize quickly until the temperature was above 350°C when heated in a static oven. The temperature impact on the formation of the various deposits was also studied in the laboratory.
Recommended Content
Authors
- Lifeng Xu - Ford Research and Innovation Center Ford Motor Company
- William Watkins - Ford Research and Innovation Center Ford Motor Company
- Rachel Snow - Ford Research and Innovation Center Ford Motor Company
- George Graham - Ford Research and Innovation Center Ford Motor Company
- Robert McCabe - Ford Research and Innovation Center Ford Motor Company
- Christine Lambert - Ford Research and Innovation Center Ford Motor Company
- R. O. Carter - Ford Research and Innovation Center Ford Motor Company
Topic
Citation
Xu, L., Watkins, W., Snow, R., Graham, G. et al., "Laboratory and Engine Study of Urea-Related Deposits in Diesel Urea-SCR After-Treatment Systems," SAE Technical Paper 2007-01-1582, 2007, https://doi.org/10.4271/2007-01-1582.Also In
References
- Held W. Konig A. Richter T. Puppe L. Society of Automotive Engineers, Paper no. 900496 1990
- takiguchi M. Ikeda M. Ichihara S. Nakahira T. Tsujimura K. Kakegawa T. Aika K. Society of Automotive Engineers, paper no. 920469 1992
- Hug H.T. Mayer A. Hartenstein A. Society of Automotive Engineers, Paper no. 930363 1993
- Heck R.M. Chen J.M. Speronello B.K. Environ. Prog 13 1994 221
- Koebel M. Elsener M. Marti T. Combust. Sci. Technol. 121 1996 85
- Hums E. Catal. Today 42 1998 25
- Muller W. Heilig D. Meyer S. Porten G. Combust. Sci. Technol. 153 2000 313
- Xu L. McCabe R.W. Hammerle R.H. Appl. Catal. B 39 2002 51 63
- Sluder C.S. Storey J.M.E. Lewis S.A. Lewis L.A. SAE 2005-01-1858
- “Urea Decomposition and SCR Performance at Low Temperature” Oak Ridge National Laboratory Engine and Emission Control Technology FreedomCAR and Vehicle Technologies Progam DOE 2005
- Fang H.L. DaCosta H.F.M. Appl. Catal. B 46 2003 17 34
- Schaber P.M. Colson J. Higgens S. Dietz E. Theilen D. Anspach B. Brauer J. American Laboratory 14 Aug. 1999 13 21
- Ball J.C. SAE 2001-01-3621
- Schaber P.M. Colson J. Higgins S. Thielen D. Anspach B. Brauer J. Thermochimica Acta 424 2004 131 142
- Kowatari T. Hamada Y. Amou K. Hamada I. Funabashi H. Takaura T. Nakagome K. SAE 2006-01-0642
- Nishioka A. Sukegawa Y. Katogi K. Mamada H. Kowatari T. Mukai T. Yokota H. SAE 2006-01-0644
- Rokosz M.J. Chen A.E. Lowe-Ma C. K. Kucherov A.V. Benson D. Paputa M.C. McCabe R.W. Appl. Catal. B: Environ 33 2001 205
- Handbook of Chemistry and Physics 63rd 1982 1983 CRC Press Boca Raton, Florida