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A Convergence Study on the Effects of NH3/NOx Ratio and Catalyst Type on the NOx Reduction by Urea-SCR System of Diesel Engine

디젤엔진의 Urea-SCR 시스템에 의한 NH3/NOx 비율 및 촉매 방식이 NOx 저감에 미치는 영향에 관한 융합연구

Yoon, Heung-Soo;Ryu, Yeon-Seung
윤흥수;류연승

  • Received : 2019.01.09
  • Accepted : 2019.04.20
  • Published : 2019.04.28

Abstract

Diesel engines have important advantages over its gasoline counterpart including high thermal efficiency, high fuel economy and low emissions of CO, HC and $CO_2$. However, NOx reducing is more difficult on diesel engines because of the high $O_2$ concentration in the exhaust, marking general three way catalytic converter ineffective. Two method available technologies for continuous NOx reduction onboard diesel engines are Urea-SCR and LNT. The implementation of the Urea-SCR systems in design engines have made it possible for 2.5l and over engines to meet the tightened NOx emission standard of Euro-6. In this study, we investigate the characteristics of NOx reduction with respect to engine speed, load, types of catalyst and the $NH_3$/NOx ratio and present the conditions which maximize NOx reduction. Also we provide detailed experimental data on Urea-SCR which can be used for the preparation for standards beyond Euro-6.

Keywords

Selective Catalytic Reduction(SCR);Ammonia($NH_3$);Cu-CHA catalysts;Cu-ZSM-5 catalysts;Euro-6

References

  1. John. B. Heywood. (1998). Internal Combustion Engine Fundamentals, 491-566. McGraw-Hill.
  2. Kraftfahrt-Bundesamt(KBA). (2008). Fuel consumption in MNEDC, at least EU4 certification.
  3. S. Jung & W. Yoon. (2008). Modeling of $NH_3$-SCR Diesel NOx Reduction and Effects of $NO_2$/NOx, $NH_3$/NO Ratio on the DeNOx Efficiency. Transactions of KSAE, 16,(3), 179-187.
  4. D. Chatterjee, T. Burkhardt, T. Rappe, A.Guthenke & M. Weibel. (2008). Numerical Simulation of DOC+DPF+SCR Systems: DOC Influence on SCR Performance. SAE 2008-01-0867.
  5. G. Madia, M. Manfred, M. Elsener & A. Wokaun. (2002). The Effect on an Oxidation Precatalyst on the NOx Reduction by Ammonia SCR. Ind. Eng. Chem. Res. 41(15), 3512-3517. https://doi.org/10.1021/ie0200555
  6. B. Yun, C. Kim, M. Kim, G. Cho, H. Kim & Y. Jeong. (2010). Numerical Modeling of Vanadia-based Commercial Urea-SCR plus DOC Systems for Heavy-duty Diesel Exhaust Aftertreatment Systems. Transactions of KSAE, 18(2), 24-30.
  7. Dieter H. E. Seher, Michael Reichelt & Stefan Wickert. (2003). Control Strategy for NOx - Emission Reduction with SCR. SAE 2003-01-3362.
  8. L. Sharifian, Y. M. Wright & K. Boulouchos. (2011). Transient simulation of NOx reduction over a Fe-Zeolite catalyst in an $NH_3$-SCR system and study of the performance under different operating conditions. SAE 2011-01-2084.
  9. G. R. Chandler, B. JCooper, J. P. Harris, J. E. Thoss, A. Uusimaki, A. P. Walker & J. P. Warren. (2000). An Integrated SCR and Continuously Regenerating Trap System to Meet Future NOx and PM Legislation. SAE 2000-01-0188.
  10. A. Herman, M. C. Wu, D. Cabush & M. Shost. (2009). Model Based Control of SCR Dosing and OBD Strategies with Feedback from $NH_3$ Sensors. SAE 2009-01-0911.
  11. J. Hu, Y. Zhao, Y. l. Zhang, S. Shuai, J. X. Wang, T. Chen & Z. Chen. (2011). Development of Closed-loop Control Strategy for Urea-SCR Based on NOx Sensors. SAE 2011-01-1324.
  12. J. S. Lee & N. Y. Kim. (2008). Characterization of SCR System for NOx Reduction of Diesel Engine (II). Transactions of KSPE, 25(11), 83-89.
  13. Y. J. Cha. (2013). An Experimental Study on NOx Reduction Characteristics using Zeolite Based Catalyst. Kookmin Univ..
  14. M. J. Song. (2013). A Numerical Analysis on $NH_3$ Flow Uniformity Depending on the Changes In shape a Diffuser and Mixer. Kookmin Univ.
  15. H. J. Kim. (2014). An Experimental Study on Charateristics of NOx Reduction with Urea-SCR System depending on EGR Type and a ratio in Passenger Diesel Engine. Kookmin Univ.