This content is not included in your SAE MOBILUS subscription, or you are not logged in.
The Effects of CO, H 2 , and C 3 H 6 on the SCR Reactions of an Fe Zeolite SCR Catalyst
ISSN: 0148-7191, e-ISSN: 2688-3627
Published April 08, 2013 by SAE International in United States
Annotation ability available
Selective Catalytic Reduction (SCR) catalysts used in Lean NOx Trap (LNT) - SCR exhaust aftertreatment systems typically encounter alternating oxidizing and reducing environments. Reducing conditions occur when diesel fuel is injected upstream of a reformer catalyst, generating high concentrations of hydrogen (H₂), carbon monoxide (CO), and hydrocarbons to deNOx the LNT. In this study, the functionality of an iron (Fe) zeolite SCR catalyst is explored with a bench top reactor during steady-state and cyclic transient SCR operation.
Experiments to characterize the effect of an LNT deNOx event on SCR operation show that adding H₂ or CO only slightly changes SCR behavior with the primary contribution being an enhancement of nitrogen dioxide (NO₂) decomposition into nitric oxide (NO). Exposure of the catalyst to C₃H₆ (a surrogate for an actual exhaust HC mixture) leads to a significant decrease in NOx reduction capabilities of the catalyst. A degradation mechanism is proposed to account for the decrease in NOx conversion efficiency, highlighted by reactions between NO₂ and C₃H₆ to make NO at a rate of similar order of magnitude as the Fast SCR reaction. This inhibits SCR reactions when the NO:NOx ratio favors NO, but can increase NOx conversion when the NO:NOx ratio favors NO₂.
Ammonia (NH₃) storage is only marginally affected by the presence of H₂, CO, or C₃H₆; but significant amounts of C₃H₆ can be stored on the catalyst. Further observation reveals that the oxidation effects of C₃H₆ are non-negligible and C₃H₆ strongly influences the oxidation of NH₃. The degradation mechanism includes seven proposed reactions to model the experimental results of adding H₂, CO, and C₃H₆ to the SCR feed gas during steady-state and transient operation.
|Technical Paper||Hydrocarbon Reactivity in a Plasma-Catalyst System: Thermal Versus Plasma-Assisted Lean NOx Reduction|
|Technical Paper||Performance of Zeolite-Based Diesel Catalysts|
CitationSmith, M., Depcik, C., Hoard, J., Bohac, S. et al., "The Effects of CO, H2, and C3H6 on the SCR Reactions of an Fe Zeolite SCR Catalyst," SAE Technical Paper 2013-01-1062, 2013, https://doi.org/10.4271/2013-01-1062.
Exhaust Emission Control, 2013
Number: SP-2338; Published: 2013-04-09
Number: SP-2338; Published: 2013-04-09
- Ball , D. , Nunan , J. , Blosser , P. , Wilson , J. et al. FlexMetal Catalyst Technologies SAE Technical Paper 2005-01-1111 2005 10.4271/2005-01-1111
- Omoto , H. , Kobayashi , T. , Ishikawa , K. , and Yamada , T. Catalyst Design for Meeting Stringent LEV-2 NOx Regulation SAE Technical Paper 2002-01-0348 2002 10.4271/2002-01-0348
- Heywood , J. Internal Combustion Engine Fundamentals 1988 New York McGraw-Hill Inc.
- Pulkrabek , W. Engineering Fundamentals of the Internal Combustion Engine 1997 New Jersey Prentice-Hall Inc.
- Stone , R. Introduction to Internal Combustion Engines Third 1999 Society of Automotive Engineers Inc. Warrendale, PA 978-0-7680-0495-3 1999
- Chimner , C. Transient On-Road Emission Reduction of an LNT + SCR Aftertreatment System SAE Int. J. Commer. Veh. 1 1 315 326 2009 10.4271/2008-01-2641
- Dykes , E. NOx Performance of an LNT+SCR System Designed to Meet EPA 2010 Emissions: Results of Engine Dynamometer Emission Tests SAE Int. J. Commer. Veh. 1 1 327 337 2009 10.4271/2008-01-2642
- Majewski , W.A. SCR Systems for Mobile Engines 2005 2005 February 9 2005 www.dieselnet.com/tech/cat_scr_mobile.html
- Olsson , L. , Sjövall H. , and Blint R.J. A kinetic model for ammonia selective catalytic reduction over Cu-ZSM-5 Applied Catalysis B: Environmental 2007 81 203 217
- Wurzenberger , J. and Wanker , R. Multi-Scale SCR Modeling, 1D Kinetic Analysis and 3D System Simulation SAE Technical Paper 2005-01-0948 2005 10.4271/2005-01-0948
- Kim , J. , Cavataio , G. , Patterson , J. , Laing , P. et al. Laboratory Studies and Mathematical Modeling of Urea SCR Catalyst Performance SAE Technical Paper 2007-01-1573 2007 10.4271/2007-01-1573
- Sjovall , H. , Blint R. , and Olsson L. Detailed Kinetic Modeling of NH 3 and H 2 O Adsorption, and NH 3 Oxidation over Cu-ZSM-5 Journal of Physical Chemistry C 2009 113 1393 1405
- Winkler , C. , Flörchinger , P. , Patil , M. , Gieshoff , J. et al. Modeling of SCR DeNOx Catalyst - Looking at the Impact of Substrate Attributes SAE Technical Paper 2003-01-0845 2003 10.4271/2003-01-0845
- Nova , I. , Ciardelli , C. , Tronconi , E. , Chatterjee , D. , and Brandl-Konrad B. NH 3 -NO/NO 2 Chemistry over V-based catalysts and its role in the mechanism of the Fast SCR reaction Catalysis Today 2006 114 3 12
- Epling , B. , Hou , P. , Luo , J. , Wijayakoon , P. , Li , W. , and Schmeig S. Spatially Resolving the Different SCR Reactions Cross-Cut Lean Exhaust Emissions Reduction Simulations Workshop 2010 2010 Deaborn Michigan
- Kuo , J. , Morgan , C. , and Lassen , H. Mathematical Modeling of CO and HC Catalytic Converter Systems SAE Technical Paper 710289 1971 10.4271/710289
- Montreuil , C. , Williams , S. , and Adamczyk , A. Modeling Current Generation Catalytic Converters: Laboratory Experiments and Kinetic Parameter Optimization - Steady State Kinetics SAE Technical Paper 920096 1992 10.4271/920096
- Olsson , L. and Andersson B. Kinetic Modelling in Automotive Catalysis Topics in Catalysis 2004 28 1 89 98
- Klinkert , S. , Hoard , J. , Sathasivam , S. , Assanis , D. , and Bohac S. Design of a Flow Reactor for Testing Multi-Brick Catalyst Systems Using Rapid Exhaust Gas Composition Switches ASME Paper ICEF2009-14016
- Smith , M. Experimental and Modeling Studies of Lean and Rich Exhaust Conditions for Selective Catalytic Reduction of NOx with NH 3 Mechanical Engineering 2010 University of Michigan Ann Arbor
- Sjovall , H. , Olsson , L. , Fridell , E. , and Blint R.J. Selective catalytic reduction of NOx with NH 3 over Cu-ZSM-5 - The effect of changing the gas composition Applied Catalysis: B Environmental 2006 64 180 188
- Louis-Rose , I. , Methivier C. , and Pradier C. Oxidation of NH 3 on polycrystalline copper and Cu(1 1 0): a combined FT-IRAS and kinetics investigation Catalysis Today 2003 85 267 278
- Kamasamudram , K. , Currier , N. , Chen , X. , and Yezerets A. Overview of the practically important behaviors of zeolite based urea-SCR catalysts, using compact experimental protocol Catalysis Today 2010 161 3-4 212 222
- Millet , C. and Benramdhane , S. A 3WCC Global Kinetic Model: A Calibration Method Using Laboratory Scale and Engine Test Bench Experiments SAE Technical Paper 2008-01-0453 2008 10.4271/2008-01-0453
- Chen , W. , Hsieg T. , and Jiang T. An experimental study on carbon monixed conversion and hydrogen generation from water gas shift reaction Energy Conversion and Management 2008 49 2801 2808
- Koltsakis , G.C. , Konstantinidis P.A. , and Stamatelos A.M. Development and Application Range of Mathematical Models for 3-Way Catalytic Converters Applied Catalysis B: Environmental 1997 12 2-3 161 191
- Koltsakis , G.C. and Stamatelos A.M. Modeling dynamic phenomena in 3-way catalytic converters Chemical Engineering Science 1999 54 4567 4578
- Sampara , C. Global Reaction Kinetics for Oxidation and Storage in Diesel Oxidation Catalysts Mechanical Engineering 2008 University of Michigan Ann Arbor 168
- Depcik , C. , Assanis D. , and Bevan K. A one-dimensional lean NOx trap model with a global kinetic mechanism that includes NH 3 and N 2 O Int, J. Engine Res. 2007 9 57 77
- Kwon , H. , Baik , J. , Kwon , Y. , Nam , I. , and Oh S. Detailed reaction kinetics over comercial three-way catalysts Chemical Engineering Science 2007 62 5042 5047
- Oh , S.H. and Cavendish J.C. Transients of Monolithic Catalytic Converters: Response to Step Changes in Feedstream Temperature as Related to Controlling Automobile Emissions Industrial and Engineering Chemistry Research 1982 21 1 29 37
- Depcik , C. , Loya S. , and Srinivasan A. Adaptive Carbon Monoxide Kinetics for Exhaust Aftertreatment Modeling 2009 ASME International Mechanical Engineering Congress & Exposition 2009 Lake Buena Vista, FL IMECE2009-11173
- He , Y. Development and Application of a Lean NOX Trap Model SAE Technical Paper 2006-01-0686 2006 10.4271/2006-01-0686
- Forzatti , P. , Lietti , L. , Nova , I. , and Tronconi E. Diesel NOx aftertreatment catalytic technologies: Analogies in LNT and SCR catalytic chemistry Catalysis Today 2010
- Yang , J. and Jung H. The effect of temperature on NOx reduction by H 2 in the presence of excess oxygen on a Pt/Al 2 O 3 monolithic catalyst Chemical Engineering Journal 2009 146 11 15
- Mosiewicz , P. , Porshnev , P. , Nester , S. , Kennedy , L. , Fridman , A. , Rabovister , J. , and Cygan D. Study of Low-Temperature Combustion in a Low-NOxBurner Combustion Science and Technology 2000 160 1 1 21
- El Kolli , N. , Potvin C. , and Thomas C. Evidence for the facile formation of nitrogen-containing compounds from NOx and propene species on tungstated zirconia-based catalysts: Are these compounds active or spectator species in the selective catalytic reduction of NOx by C 3 H 6 Journal of Catalysis 2008 259 2 240 249
- Luo , J. , Oh , H. , Henry , C. , and Epling W. Effect of C 3 H 6 on Selective Catalytic Reduction of NOx by NH 3 over a Cu/zeolite Catalyst: A Mechanistic Study Applied Catalysis B: Environmental 2012 123-124 296 305
- Montreuil , C. and Lambert , C. The Effect of Hydrocarbons on the Selective Catalyzed Reduction of NOx over Low and High Temperature Catalyst Formulations SAE Int. J. Fuels Lubr. 1 1 495 504 2009 10.4271/2008-01-1030
- Saidina Amin , N.A. and Chong C.M. SCR of NO with C 3 H 6 in the presence of excess O 2 over Cu/Ag/CeO 2 -ZrO 2 catalyst Chemical Engineering Journal 2005 113 1 13 25