Journal of Advanced Marine Engineering and Technology

The Korean Society of Marine Engineering (한국마린엔지니어링학회)
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Experimental study of NOx reduction in marine diesel engines by using wet-type exhaust gas cleaning system

선박용 디젤엔진의 NOx를 저감하기 위한 습식 배기가스 처리기술 적용에 관한 실험적 연구

  • Received : 2017.01.19
  • Accepted : 2017.03.06
  • Published : 2017.03.31
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Abstract

Diesel engines have the highest brake thermal efficiency among internal combustion engines. Therefore, they are utilized in medium and large transportation vehicles requiring large amounts of power such as heavy trucks, ships, power generation systems, etc. However, diesel engines have a disadvantage of generating large quantities of nitrogen oxides during the combustion process. Therefore, the authors tried to reduce the amount of nitrogen oxides in marine diesel engines using a wet-type exhaust gas cleaning system utilizing the undivided electrolyzed seawater method. In this method, electrolyzed seawater in injected into the harmful gas discharge from the diesel engine using real seawater. The authors investigated the reduction of NO and NOx from the pH value, available chlorine concentration, and the temperature of electrolyzed seawater. The results of this experiment indicated that when the electrolyzed seawater is acidic, the NO oxidation rate in the oxidation tower is higher than that when the electrolyzed seawater has a neutral pH. Likewise, the NO oxidation rate increased with the increase in concentration of chlorine. Further, it was confirmed that the electrolyzed seawater temperature had no effect on the NO oxidation rate. Thus, the NOx exhaust emission value produced by the diesel engine was reduced by means of electrolyzed seawater treatment.

디젤엔진은 내연기관 중에 제동 열효율이 가장 높은 엔진이기 때문에 큰 동력을 필요로 하는 대형트럭과 같은 중 대형 운송 차량 및 선박 등의 수송분야 및 발전시스템 등의 다양한 분야에서 사용되어지고 있다. 하지만, 디젤엔진은 연소과정에서 질소산화물(이하 NOx) 발생량이 많은 단점을 가지고 있다. 따라서 본 연구에서는 선박용 디젤엔진의 NOx를 저감하기 위해서 습식 배기가스 처리 기술인 무격막식 해수 전기분해 방식을 이용하여 NOx 저감을 시도하였다. 실제 해수를 사용하여 디젤엔진에서 배출되는 유해가스에 전기 분해된 해수인 전해수를 분사하여 보았다. 전해수의 pH 농도 및 유효염소농도, 온도에 따른 NO 산화율 및 NOx 감소량을 조사하였다. 본 실험을 통해서 전해수의 pH가 약산성 영역일 경우가 중성일 경우보다 산화탑에서의 NO 산화율이 상승하였고, 유효염소농도가 높을수록 NO 산화율이 증가하는 것을 확인할 수 있었다. 또한, 전해수 온도는 NO 산화율에 영향이 없음을 추가적으로 확인할 수 있었으며 디젤엔진에서 생성된 배기배출물에 전해수를 분사함으로써 NOx가 저감됨을 확인할 수 있었다.

Keywords

References

  1. Jo. B. Heywood, Internal Combustion Engine Fundamentals, New York, USA, McGraw-Hill, Inc., 1988.
  2. W. W. Pulkrabek, Engineering Fundamentals of the Internal Combustion Engine, 2ND Edition, Pearson, 2004.
  3. https://www.dieselnet.com, Accessed January 17 2017.
  4. D. Blanco-Rodriguez, G. Vagnoni, and B. Holderbaum, "EU6 C-segment diesel vehicles, a challenging segment to meet RDE and WLTP requirements," IFAC-PapersOnLine, vol. 49, no. 11, pp. 649-656, 2016.
  5. Y. H. Ryu, Y. S. Lee, and J. G. Nam, "An experimental study of the fuel additive to improve the performance of a 2-stroke large diesel engine," Journal of the Korean Society of Marine Engineering, vol. 39, no. 6, pp. 620-625, 2015 (in Korean). https://doi.org/10.5916/jkosme.2015.39.6.620
  6. Y. H. Ryu, Y. S. Lee, and J. G. Nam, "Performance and emission characteristics of additives-enhanced heavy fuel oil in large two-stroke marine diesel engine," Fuel, vol. 182, pp. 850-856, 2016. https://doi.org/10.1016/j.fuel.2016.06.029
  7. Y. H. Ryu, Y. S. Lee, and J. G Nam, "Improvement of the performance and emission in a four-stroke diesel engine using fuel additive," Journal of the Korean Society of Marine Engineering, vol. 40, no. 9, pp. 762-767, 2016 (in Korean). https://doi.org/10.5916/jkosme.2016.40.9.762
  8. Y. H. Ryu, H. R. Kim, G. B. Cho, H. S. Kim, and J. G. Nam, "A study on the installation of SCR system for generator diesel engine of existing ship," Journal of the Korean Society of Marine Engineering, vol. 39, no. 4, pp. 412-417, 2015 (in Korean). https://doi.org/10.5916/jkosme.2015.39.4.412
  9. G. Panomsuwan, R. Rujiravanit, T. Ueno, and N. Saito, "Non-thermal plasma technology for abatement of pollutant emission from marine diesel engine," Journal of the Korean Society of Marine Engineering, vol. 40, no. 10, pp. 929-934, 2016. https://doi.org/10.5916/jkosme.2016.40.10.929
  10. T. W Kim, S. J. Choi, J. H. Kim, and J. Y. Song, "A study on the NOx reduction of flue gas using un-divided electrolysis of seawater," Korean Chemical Engineering Research, vol. 50, no. 5, pp. 825-829, 2012 (in Korean). https://doi.org/10.9713/kcer.2012.50.5.825
  11. T. W. Kim, J. H. Kim, and J. Y. Song, "A study on the NOx reduction of flue gas using seawater electrolysis," Journal of the Korean Oil Chemist′ Society, vol. 29, no. 4, pp. 570-576, 2012 (in Korean). https://doi.org/10.12925/jkocs.2012.29.4.570
  12. L. Chen, C. H. Hsu, and C. L. Yang, "Oxidation and absorption of nitric oxide in a packed tower with sodium hypochlorite aqueous solutions," Environmental Progress, vol. 24, no. 3, pp. 279-288, 2005. https://doi.org/10.1002/ep.10075
  13. L. R. Czarnetzki and L. J. J. Janssen, "Formation of hypochlorite, chlorate and oxygen during NaCl electrolysis from alkaline solutions at an $RuO_2$/$TiO_2$ anode", Journal of Applied Electrochemistry, vol. 22, pp. 315-324, 1992. https://doi.org/10.1007/BF01092683
  14. J. H. Park and S. H. Paik, "The problems of chemistry teachers' and pre-service teachers' conceptions in the prediction of electrolysis products," Journal of the Korean Chemical Society, vol. 48, no. 5, pp. 519-526, 2004 (in Korean). https://doi.org/10.5012/jkcs.2004.48.5.519
  15. H. J. Park, S. W. Lee, M. G. Ku, and J. H. Lim, "Electrochemical treatment of dye wastewater using $IrO_2$/Ti electrode," Applied Chemistry, vol. 14, no. 1. pp. 37-40, 2010.
  16. S. H. An, "Air pollution protection onboard by seawater and electrolyte," Journal of the Korean Society of Marine Engineering, vol. 30, no. 1, pp. 93-101, 2006.
  17. S. S. Kim, H. J. Choi, and S. C. Hong, "A study on reaction characteristics of $H_2$ SCR using Pt/$TiO_2$ catalyst," Applied Chemistry for Engineering, vol. 21, no. 1, pp. 18-23, 2010.
  18. Z. Liu, J. Li, and S. I. Woo, "Recent advances in the selective catalytic reduction of NOx by hydrogen in the presence of oxygen," Energy & Environmental Science, 5, pp. 8799-8814, 2012. https://doi.org/10.1039/c2ee22190j
  19. M. Henze, M. C. M, van Loosdrecht, G. A. Ekama, and D. Brdjanovic, Biological Wastement Treatment, IWA Publishing Books, p. 236, 2008.
  20. R. T. Guo, W. G. Pan, X. B. Zhang, H. J. Xu, Q. Jin, C. G. Ding, and S. Y. Guo, "The absorption kinetics of NO into weakly acidic NaClO solution," Separation Science and Technology, vol. 48, no. 18, pp. 2871-2875, 2013. https://doi.org/10.1080/01496395.2013.808214

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