This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Desulafation Dynamics of NOx Storage Catalysts
Technical Paper
2002-01-2886
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
The dynamics of the desulfation of a Ba-containing and a K-containing NOx storage catalyst have been investigated. When both catalysts were desulfated using a temperature ramp in exhaust that simulated gasoline exhaust with a 13:1 A/F, the maximum desulfation rate for the Ba-containing catalyst was seen at 620°C, while the maximum for the K-containing catalyst was at 760°C. This is consistent with the widely known fact that K2SO4 is more stable than BaSO4.
The BaSO4 decomposed when either hydrogen or water was in the feed, but not when both were absent. The decomposition, therefore, requires hydrogen to be present and the water can provide sufficient hydrogen for the decomposition via the water-gas shift reaction. With either water or hydrogen in the uncycled feed, the primary sulfur compound formed from the decomposition was H2S for both the Ba and K-containing catalysts.
Cycling the feed increased the amount of sulfur released as SO2 from the Ba-containing catalyst, but was not as effective in removing sulfur as continuous rich operation. Cycling the feed to the K-containing catalyst greatly reduced the desulfation of the catalyst without significantly increasing the sulfur release as SO2.
Thermodynamic calculations of the desulfation reactions with CO or H2 are consistent with the experimental results. The sulfates (K2SO4, BaSO4, and Ce2(SO4)3) are far less stable in H2 than in CO and their decomposition to form H2S is clearly favored over their reactions with CO to form SO2. Among these sulfates, Ce2(SO4)3 is the least stable and is the only one that decomposes in the absence of hydrogen.
Recommended Content
Technical Paper | Hydrogen Added After-Burner System |
Technical Paper | NOx Destruction Behavior of Select Materials When Combined with a Non-Thermal Plasma |
Technical Paper | Performance Analysis of 18% HCNG fuel on Heavy Duty Engine |
Authors
Citation
Monroe, D. and Li, W., "Desulafation Dynamics of NOx Storage Catalysts," SAE Technical Paper 2002-01-2886, 2002, https://doi.org/10.4271/2002-01-2886.Also In
References
- Miyoshi, N. Matsumoto, S. Katoh, K. Tanaka, T. Harada, J. Takahashi, N. Yoaota, K. Sugiura, M. Kasahara, K. “Development of New Concept Three-Way Catalyst for Automotive Lean Burn Engines” S.A.E. Paper 950809 1995
- Iwachido, K. Tanada, H. Wananabe, T. Yamada, N. Nakayama, O. Ando, H. Hori, M. Taniguchi, S. Noda, N. Abe, F. “Development of the NOx Adsorber Catalyst for Use with High-Temperature Condition” SAE Paper 2001-01-1298 2001
- Brogan, M.S. BrisleY, R.J. Walker, A. P. Webster, D. E. Boegner, W. Fekete, N.P. Kramer, M. Krutzsch, B. Voightlander, D. “Evaluation of NOx Storage Catalysts as an Effective System for NOx Removal from the Exhaust Gas of Lean Burn Gasoline Engines” SAE Paper 952490 1995
- Hepburn, J. S. Tanasiu, E. Dobson, D.A. Watkins, W.L. “Experimental and Modeling Investigations of NOx Trap Performance” SAE Paper 962051 1996
- Strehlau, W. Leyrer, J. Lox, E. S. Kreuzer, T. Hori, M. Hoffman, M. “New Development in Lean NOx Catalysis for Gasoline Fueled Passenger Cars in Europe” SAE Paper 962047 1996
- Fekete, N. Kemmler, R. Voighlander, D. Krutzsch, B. Zimmer, E. ‘Wenninger, G. Strehlau, W. van den Tillaart, J. A. Leyrer, J. Lox, E.S. Muller, W. “Evaluation of NOx Storage Catalysts for Lean Bum Gasoline Fueled Passenger Cars” SAE Paper 970746 1997
- Bailey; O.H. Dou; D. Denison; G.W. “Regeneration Strategies for NOx Adsorption Catalysts” SAE Paper 972845 1997
- Koseki, K. Uchiyama, T. Kawamura, M. Shigeo, s. “A study of the effects of sulfur in gasoline on exhaust emissions” SAE Paper # 2000-01-1878
- Asanuma, T. Takeshima, S. Yamashita, T. Tanaka, T. Murai, T. Iguchi, S. Influence of sulfur concentration in gasoline on NOx storage-reduction” SAE Paper 1999-01-3501
- Li, A Theis, J.R. Chun, C. Goralski, C.T. Kudla, R.J. Watkins, W.L. Hurley, R.H. “Sulfur Poisoning and Desulfation th the Lean NOx Trap” SAE Paper 2001-01-2503 2001
- ACGIH 1991 Documentation of the Threshold Limit values and Biological Exposure Indices sixth American Conference of Governmental Industrial Hygienists, Inc. Cincinnati, OH 786 788
- Erkfeldt, S. Larsson, M. Hedblom, H. Skoglundh, M. “Sulfur Poisoning and Regeneration of NO x Trap Catalysts for Direct-Injection Gasoline Engines” S.A.E. Paper # 1999-01-3504
- Ziolek, M. Kujaawa, J. Saur, O. Aboulayt, A. Lavalley, J.C. Journal of Molecular Catalysis A: Chemical 1996 112 125 132
- Asik, J.R. Dobson, D.A. Meyer, G.M. “Supression of Sulfide Emissions During NO x Trap Regeneration” S.A.E. Paper # 2001-01-1299
- Schmieg, S. J. Belton, D. N. “Effect of Hydrothermal Aging on Oxygen Storage/Release and Activity in a Commercial Automotive Catalyst” Appl. Catal. B: Environ. 6 127 144 1995