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Swetha Bandaru,
Jayaprabakar Jayaraman,
Abstract
Selective Catalytic Reduction (SCR) is an effective aftertreatment technique designed to comply with rigorous emission criteria established by global regulatory authorities for the elimination of nitrogen oxides from exhaust streams. Since NOx and ammonia reagents are poisonous and an excess of either is therefore very undesired, it poses an intriguing control problem, particularly at high conversion. SCR systems must reduce NOx emissions as much as possible and reduce the possibility of solid deposit fouling, which can harm both the engine and the SCR system. The injection and vaporization of the urea, as well as the diffusion of ammonia in the exhaust gases, have a major impact on both.
Undecomposed urea can cause solid deposits to form, which unpleasantly impact system performance by raising back pressure of engine and lowering overall fuel efficiency. Two SCR models were evaluated: a base and a revised model, both simulated using CFD. The revised design demonstrated a significant 48.8% reduction in accretion rate and better NOx reduction performance, while compared with base model. Incorporate the hybrid mixer to enhance the SCR system efficiency in revised SCR model, compares the two optimized designs of Hybrid mixers. Mixer 1 design is better suitable to reduce the solid deposits and enhance the SCR system performance. The mixer 1 design achieves 4% reduction in accretion rate compared with mixer2 design of hybrid mixer in revised SCR model.
Keywords: Solid Deposits, Selective Catalytic Reduction, Mixer design, After treatment system, NOx reduction, optimized design.Solid Deposits, Selective Catalytic Reduction, Mixer design, After treatment system, NOx reduction, optimized design.
Swetha Bandaru, Jayaprabakar Jayaraman. Dosing Control of Urea in Selective Catalytic Reduction (SCR) to enhance the reduction of Nitrogen oxides. Journal of Polymer and Composites. 2025; 13(05):-.
Swetha Bandaru, Jayaprabakar Jayaraman. Dosing Control of Urea in Selective Catalytic Reduction (SCR) to enhance the reduction of Nitrogen oxides. Journal of Polymer and Composites. 2025; 13(05):-. Available from: https://journals.stmjournals.com/jopc/article=2025/view=0
References
- Palash S. M, Kalam M.A, Masjuki H.H, et al. Impacts of biodiesel combustion on NOx emissions and their reduction approaches. Renewable and Sustainable Energy Reviews. 2013; 23 (July 2013): 473–490
- Saleh HE. Effect of exhaust gas recirculation on diesel engine nitrogen oxide reduction operating with jojoba methyl ester. Renewable Energy. 2009; 34(10):2178–2186
- Tauzia X, Maiboom A, Rahman Shah S. Experimental study of inlet manifold water injection on combustion and emissions of an automotive direct injection diesel engine. 2010; 35(9):3628–3639.
- Mohammud Hanif Dewan. Marine Diesel Engine Exhaust Gas Emissions Control Technologies. 2014.
- Mehdi, G., Zhou, S., Zhu, Y., Shah, A., & Chand, K. Numerical Investigation of SCR Mixer Design Optimization for Improved Performance. Processes. 2019; 7(3), 168. doi:10.3390/pr7030168
- Venkatesh A, Ramesh K. Design of Static Mixer to Improve the Uniformity Index In Urea SCR System. 2019; 5(5). ISSN :2395-1052.
- Fischer S, Bitto R, Lauer T. et al. Impact of the Turbulence Model and Numerical Approach on the Prediction of the Ammonia Homogenization in an Automotive SCR System. SAE International Journal of Engines. 2012; 5(3), 1443–1458. doi:10.4271/2012-01-1291
- Park T, Sung Y, Kim T, Lee I. et al. Effect of static mixer geometry on flow mixing and pressure drop in marine SCR applications. International Journal of Naval Architecture and Ocean Engineering. 2014; 6(1), 27–38. doi:10.2478/ijnaoe-2013-0161
- Smith H, Zöchbauer M, Lauer T. Advanced Spray Impingement Modelling for an Improved Prediction Accuracy of the Ammonia Homogenization in SCR Systems. SAE Technical Paper Series. 2015. doi:10.4271/2015-01-1054.
- Ryan Eamon. European Union (Road Vehicles: Type – Approval and Market Surveillance) Regulations. Iris Oifigiúil. 2024; S.I. No. 201/2024.
- Martin Williams, Ray Minjares. A technical summary of Euro 6/VI vehicle emission standards. The International Council on Clean Transportation. 2016; Available from: https://theicct.org/sites/default/files/publications/ICCT_Euro6-VI_briefing_jun2016.pdf
- Zhiqing Zhang, Ziheng Zhao, Dongli Tan, et al. Experimental study of ammonia storage characteristics of selective catalytic reduction for diesel engine based on Cu-based catalysts. Process Safety and Environmental Protection. 2024; Volume 190, Part A, Pages 368-380
- Cavataio G, Girard J, Lambert C. Cu/Zeolite SCR on High Porosity Filters: Laboratory and Engine Performance Evaluations. SAE Technical Paper. 2009; 2009-01-0897. https://doi.org/10.4271/2009-01-0897.
- Haozhong Huang, Yajuan Chen, Zhihua Li, et al. Analysis of deposit formation mechanism and structure optimization in urea-SCR system of diesel engine. Fuel. 2020; Volume 265. https://doi.org/10.1016/j.fuel.2019.116941
- Anna Sandström. Investigation into Urea Deposit Risk by varying parameters in the control system related to urea evaporation [Master’s Thesis]. Scania CV AB, Sweden. KTH Royal Institute of Technology. 2022.
- Strots V, Santhanam S, Adelman B, et al. Deposit Formation in Urea-SCR Systems. SAE International Journal of Fuels and Lubricants. 2010; 2(2):283-289. https://doi.org/10.4271/2009-01-2780.
- Vernham, B, Kadam V, Masoudi M, Noorfeshan S, et al., Electrically Heated Mixer for Near-Zero Urea Deposit. SAE Technical Paper. 2024; 2024-01-2377. https://doi.org/10.4271/2024-01-2377.
- Herman A, Ming-Cheng Wu, Cabush D, et al. Model Based Control of SCR Dosing and OBD Strategies with Feedback from NH3 SAE International Journal of Fuels and Lubricants. 2009; Volume 2 (1). 2009-01-0911.
- Guo G, Warner J, Cavataio G, et al. The Development of Advanced Urea-SCR Systems for Tier 2 Bin5 and Beyond Diesel Vehicles. SAE Technical Paper. 2010; 2010-01-1183. https://doi.org/10.4271/2010-01-1183.
- Sahar Elkaee, Ajit Dattatray Phule, Jae Hwan Yang. Advancements in (SCR) technologies for NOx reduction: A comprehensive review of reducing agents. Process Safety and Environmental Protection. 2024; Volume 184, Pages 854-880.
- Zhengguo Chen, Qingyang Liu, Haoye Liu, et al. Recent Advances in SCR Systems of Heavy-Duty Diesel Vehicles – Low Temperature NOx Reduction Technology and Combination of SCR with Remote OBD. Atmosphere 2024, 15(8), 997.
- Jiarui Wu, Guofu Liu, Xin Zhang, Chao Zhang, et al. Design and Verification of Key Components of a New Selective Catalytic Reduction System in a Petrochemical Captive Power Plant. 2023; 11(10), 2837.
- Michiel J Van Nieuwstadt, Devesh U. Exhaust gas aftertreatment systems. FORD GLOBAL TECHNOLOGIES, LLC. 2004. Pub Num: US20040098968A1. App Num:US10/301,387
- Swetha Bandaru, Jayaprabakar J, Anbazhaghan N, et al. Comparative analysis of mixer designs for optimized NOx reduction and accretion control in SCR systems. Results in Engineering. 2025; 26, 104878.

Journal of Polymer and Composites
| Volume | 13 |
| 05 | |
| Received | 10/06/2025 |
| Accepted | 02/07/2025 |
| Published | 17/07/2025 |
| Publication Time | 37 Days |
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