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Influence of Hydrocarbon Storage on the Durability of SCR Catalysts
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 14, 2008 by SAE International in United States
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Selective catalytic reduction (SCR) is a technology capable of meeting Tier 2 Bin 5 emissions levels of oxides of nitrogen (NOX) for diesel engines. Base metal zeolite catalysts show the best combination of thermal durability and NOX conversion activity. It is shown in this work that some base metal zeolite catalysts can store high levels of hydrocarbons (HCs). Also, base metal zeolite catalysts can catalyze oxidation of HCs under certain conditions. Oxidation of stored hydrocarbons can lead to permanent catalyst deactivation due to the exotherm generated in the SCR catalyst (over-temperature condition leading to SCR catalyst damage). This paper discusses a laboratory bench test to characterize hydrocarbon storage and burn-off characteristics of several SCR catalyst formulations, as well as engine dynamometer tests showing hydrocarbon storage and exotherm generation. The storage of hydrocarbons is primarily a concern at temperatures below around 200°C, and the oxidation occurs at temperatures around 300°C to 350°C. It is shown that improved SCR formulations have lower HC storage and therefore have much less risk of exotherms based on hydrocarbon storage.
CitationGirard, J., Snow, R., Cavataio, G., and Lambert, C., "Influence of Hydrocarbon Storage on the Durability of SCR Catalysts," SAE Technical Paper 2008-01-0767, 2008, https://doi.org/10.4271/2008-01-0767.
- Lambert, C. Hammerle, R. McGill, R. Khair, M. Sharp, C. 2004 “Technical Advantages of Urea SCR for Light-Duty and Heavy-Duty Diesel Vehicle Applications,” SAE Paper No. 2004-01-1292
- Tennison, P. Lambert, C. Levin, M. 2004 “NOx Control Development with Urea SCR on a Diesel Passenger Car,” SAE Paper No. 2004-01-1291
- Lambert, C. Montreuil, C. Vanderslice, J. 2003 “Application of Organic Freeze-Point Depressants in Aqueous Urea Solutions: Effect on NOx Reduction,” SAE Paper No. 2003-01-0775
- van Kooten, W.E.J. Krijnsen, H.C. van den Bleen, C.M. Calis, H.P.A. 2000 “Deactivation of Zeolite Catalysts Used for NOx Removal,” Appl. Catal. B: Env. 25 2000 125 135
- Schmieg, S.J. Cho, B.K. Oh, S.H. “Hydrocarbon Reactivity in a Plasma-Catalyst System: Thermal Versus Plasma-Assisted Lean NOx Reduction,” SAE Paper No. 2001-01-3565
- Adams, K. M. Cavataio, J. V. Hammerle, R. H. “Lean NOx Catalysis for Diesel Passenger Cars: Investigating Effects of Sulfur Dioxide and Space Velocity,” Appl. Catal. B: Env. 10 1996 157 181