This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Modeling of the Injection and Decomposition Processes of Urea-Water-Solution Spray in Automotive SCR Systems
Technical Paper
2011-01-1317
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
The current work aims to develop a reliable numerical model simulating the depletion and decomposition process of urea-water solution (UWS) droplets injected in a hot exhaust stream as experienced in an automotive urea-based selective catalytic reduction (SCR) system. The depleting process of individual UWS droplets in heated environment is simulated using a multicomponent vaporization model with separate depletion law for each component. While water depletion is modeled as a vaporization process, urea depletion from the UWS droplet is modeled using two different approaches. The first approach models urea depletion as a vaporization process with an experimentally determined saturation pressure. The second approach models urea depletion as a direct thermolysis process from molten urea to ammonia and isocyanic acid using various sets of kinetic parameters. Comparison with experimental data shows the superiority of modeling urea depletion as a vaporization process. The developed multicomponent vaporization model is implemented into a computational fluid dynamics code to simulate the injection of UWS spray and its interaction with the hot exhaust gas inside a typical exhaust pipe. While the exhaust gas is treated using the Eulerian frame of reference, the injected UWS droplets are tracked in the Lagrangian frame. Ammonia production from the evaporated urea is modeled using two-steps finite rate chemical reactions involving urea thermolysis and hydrolysis of isocyanic acid. The influence of operating conditions on ammonia generation from a UWS spray is investigated.
Recommended Content
Authors
Topic
Citation
Abu-Ramadan, E., Saha, K., and Li, X., "Modeling of the Injection and Decomposition Processes of Urea-Water-Solution Spray in Automotive SCR Systems," SAE Technical Paper 2011-01-1317, 2011, https://doi.org/10.4271/2011-01-1317.Also In
References
- Johnson, T.V. “Review of Diesel Emissions and Control,” SAE Int. J. Fuels Lubr. 3 1 16 29 2010 10.4271/2010-01-0301
- Twigg, M. V. “Progress and Future Challenges in Controlling Automotive Exhaust Gas Emissions,” Appl. Catal. B-Environ. 70 2 15 2007
- Cooper, B. J. McDonald, A. C. Walker, A. P. Sanchez, M. “The Development and on-Road Performance and Durability of the Four-Way Emission Control SCRT System,” US Department of Energy Emission Reduction (DEER) Conference Newport, Rhode Island 2003
- ACEA Report on Selective Catalytic Reduction “The Most Promising Technology to Comply with Imminent Euro IV and Euro V Emissions Standards for HD Engines,” Final Report 2003
- Koebel, M. Elsener, M. Kleemann, M. “Urea-SCR: a Promising Technique to Reduce NO x Emissions from Automotive Diesel Engines,” Catal. Today 59 335 345 2000
- Kleemann, M. Elsener, M. Koebel, M. Wakaun, A. “Hydrolysis of Isocyanic Acid on SCR catalysts,” Ind. Eng. Chem. Res. 39 4120 4126 2000
- Gabrielsson, P.L.T. “Urea-SCR in Automotive Applications,” Top. Catal. 28 177 184 2004
- Elvers, B. “Ullmann's Encyclopedia of Industrial Chemistry,” 5th VCH Weinheim A27 358 365 1985
- Johnson, T.V. “Diesel Emission Control in Review,” SAE Int. J. Fuels Lubr. 1 1 68 81 2008 10.4271/2008-01-0069
- Weisweiler, W. Buchholz, F. “Fester Harnstoff als Ammoniakquelle für die katalysierte Stickstoffoxid-Minderung in Dieselabgasen nach dem SCR-Verfahren,” Chem. Ing. Tech. 73 882 887 2001
- Tarabulski, T. J. Peter-Hoblyn, J.D. Valentine, J.M. “Reducing NO x Emission from and Engine by Selective Catalytic Reduction Utilitzing Solid Reagents,” U.S. Patent 5 809 775 Sep. 22 1998
- Jacob, E. Käfer, S. Müller, W. Lacroix, A. Herr, A. “Method and Apparatus for Producing Ammonia (NH 3 ),” U.S. Patent 6 928 807 Aug. 16 2005
- Koebel, M. Strutz, E.O. “Thermal and Hydrolytic Decomposition of Urea for Automotive Selective Catalytic Reduction Systems: Thermochemical and Practical Aspects,” Ind. Eng. Chem. Res. 42 2093 2100 2003
- Sluder, C.S. Storey, J.M.E. Lewis, S.A. Lewis, L.A. “Low Temperature Urea Decomposition and SCR Performance,” SAE Technical Paper 2005-01-1858 2005 10.4271/2005-01-1858
- Abu-Ramadan, E. Li, X. “Recent Advances and Future Challenges in the Modeling and Simulation of the Injection of Urea-Water-Solution for Automotive SCR Systems,” 2009 Directions in Energy-Efficiency and Emissions Research (DEER) Conference Dearborn, Michigan, USA 2009
- Munnannur, A. Liu, Z.G. “Development and Validation of a Predictive Model for DEF Injection and Urea Decomposition in Mobile SCR DeNOx Systems,” SAE Technical Paper 2010-01-0889 2010 10.4271/2010-01-0889
- Kim, J.Y. Ryu, S.H. Ha, J.S. “Numerical Predictions on the Characteristics of Spray-Induced Mixing and Thermal Decomposition of Urea Solution in SCR System,” Proc. 2004 Fall Technical Conference of the ASME Internal Combustion Engine Division Long Beach, California, USA 2004
- Birkhold, F. Meingast, U. Wassermann, P. Deutschmann, O. “Analysis of the Injection of Urea-Water-Solution for Automotive SCR DeNOx-Systems: Modeling of Two-Phase Flow and Spray/Wall-Interaction,” SAE Technical Paper 2006-01-0643 2006 10.4271/2006-01-0643
- Birkhold, F. Meingast, U. Wassermann, P. Deutschmann, O. “Modeling and Simulation of the Injection of Urea-Water-Solution for Automotive SCR DeNO x -Systems,” Appl. Catal. B-Environ. 70 119 127 2007
- Yi, Y. “Development of a 3D Numerical Model for Predicting Spray, Urea Decomposition and Mixing in SCR Systems,” SAE Technical Paper 2007-01-3985 2007 10.4271/2007-01-3985
- Ström, H. Lundström, A. Andersson, B. “Choice of Urea-Spray Models in CFD Simulations of Urea-SCR Systems,” Chem. Eng. J. 150 69 82 2009
- Wang, T.J. Baek, S.W. Lee, S.Y. Kang, D.H. Yeo, G.K. “Experimental Investigation on Evaporation of Urea-Water-Solution Droplet for SCR Applications,” AIChE. J. 55 3267 3276 2009
- Sirignano, W.A. “Fluid Dynamics and Transport of Droplets and Sprays,” Cambridge University Press London 1999
- Renksizbulut, M. Bussmann, M. Li, X. “A Droplet Vaporization Model for Spray Calculations,” Part. Part. Syst. Charact. 9 59 95 1992
- Saha, K. Abu-Ramadan, E. Li, X. “Multicomponent Evaporation Model for Pure and Blended Biodiesel Droplets in High Temperature Convective Environment,” 5 th International Green Energy Conference (IGEC-V) Waterloo, Ontario, Canada 2010
- Dittus, F. W. Boelter, M. K. Univ. Calif. Berkely Publ. Eng. 2 433 1930
- Stiesch, G. “Modeling Engine Spray and Combustion Processes” Springer-Verlag Berlin 2003
- Fluent 6.3 User Manual
- Taylor, G. I. “The Shape and Acceleration of a Drop in a High Speed Air Stream” Scientif Papers of G. I. Taylor Batchelor, G. K. 1963
- O'Rourke, P. J. “Collective Drop Effects on Vaporizing Liquid Sprays” Ph.D. Thesis Princeton University Princeton, New Jersey 1981
- Clift, R. Grace, J.R. Weber, M.E. “Bubbles, Drops, and Particles,” Academic Press New York 1978
- Ranz, W.E. Marshall, W.R. “Evaporation From Drops,” Chem. Eng. Prog. 487 141 146 173 180 1952
- Abu-Ramadan, E. Saha, K. Li, X. “Modeling the Depletion Mechanism of Urea-Water-Solution Droplet for Automotive Selective Catalytic Reduction Systems,” AIChE. J. 10.1002/aic.12523
- Schaber, O. M. Colson, J. Higgins, S. Thielen, D. Anspach, B. Brauer, J. “Thermal Decomposition (Pyrolysis) of Urea in an Open Reaction Vessel,” Thermochim Acta 424 131 142 2004
- Poling, B. E. Prauznitz, J. M. O'Connell, J. P. “The Properties of Gaseous and Liquids,” 5th McGraw-Hill New York 2001
- “Gmelin Handbook,” D1 410 411
- “AdBlue, Technical Leaflet” BASF Aktiengesellschaft Ludwigshafen, Germany February 2005
- Longsworth, L. G. “Temperature Dependence of Diffusion in Aqueous Solutions,” J. Phys. Chem. 58 770 773 1954
- Emel'yanenko, V. N. Kabo, G. J. Verevkin, S. P. “Measurement and Prediction of Thermochemical Properties: Improved Increments for the Estimation of Enthalpies of Sublimation and Standard Enthalpies of Formation of Alkyl Derivatives of Urea,” J. Chem. Eng. Data 51 79 87 2006
- Yim, S. D. Kim, S. J. Baik, J. H. Nam, I. Mok, Y. S. Lee, J. H. Cho, B. Oh, S. H. “Decomposition of Urea into NH 3 for the SCR Process,” Ind. Eng. Chem. Res. 43 4856 4863 2004
- Aoki, H. Fujiwara, T. Morozumi, Y. E. Miura, T. “Measuremetns of Urea Thermal Decomposition Reaction for NO Selective non-Catalytic Reduction,” Proc. of 5 th International Conference on Technologies and Combustion for a Clean Environment Instituto Superior Técnico Lisbon, Portugal 115 118 1999