Journal of Korean Society of Environmental Engineers (대한환경공학회지)

Korean Society of Environmental Engineers (대한환경공학회)
권호 표지

Simultaneous Removal of $SO_2$ and NOx Using Ozone Generator and Absorption- Reduction Technique

오존발생장치와 흡수환원법을 이용한 배기가스 동시 탈황 탈질 공정

  • Mok, Young-Sun (Department of Chemical Engineering & Clean Technology, Cheju National University) ;
  • Lee, Joo-Hyuck (Department of Chemical Engineering & Clean Technology, Cheju National University) ;
  • Shin, Dong-Nam (Environment Research Team, Research Institute of Industrial Science and Technology) ;
  • Koh, Dong-Jun (Environment Research Team, Research Institute of Industrial Science and Technology) ;
  • Kim, Kyong-Tae (Environment Research Team, Research Institute of Industrial Science and Technology)
  • 목영선 (제주대학교 청정화학공학과) ;
  • 이주혁 (제주대학교 청정화학공학과) ;
  • 신동남 (포항산업과학연구원 환경연구팀) ;
  • 고동준 (포항산업과학연구원 환경연구팀) ;
  • 김경태 (포항산업과학연구원 환경연구팀)
  • Published : 2006.02.28
Download PDF
⟨ Previous Next ⟩

Abstract

The injection of ozone, produced by dielectric barrier discharge, into the exhaust gas gives rise to a rapid oxidation of NO that is the main component of nitrogen oxides($NO_x$) in most practical exhaust gases. Once NO is converted into $NO_2$, it on readily be reduced to $N_2$ in the next step by a reducing agent such as sodium sulfide and sodium sulfite. The reducing agents used ca also remove $SO_2$ effectively, which makes it possible to treat $NO_x\;and\;SO_2$ simultaneously. The present two-step process made up of an ozonizing chamber and an absorber containing a reducing agent solution was able to remove about 95% of the $NO_x$ and 100% of the $SO_2$, initially contained in the simulated exhaust gas. The formation of $H_2S$ from sodium sulfide was prevented by using a strong basic reagent(NaOH) together with the reducing agent. The removal of $NO_x$\;and\;SO_2$ was more effective for $Na_2S$ than $Na_2SO_3$.

유전체장벽방전에 의해 발생된 오존을 배기가스에 주입하면 질소산화물의 주성분인 NO가 빠르게 $NO_2$로 산화된다. 일단 NO가 $NO_2$로 산화되면 다음 단계에서 황화나트륨이나 아황산나트륨과 같은 환원제에 의해 쉽게 $N_2$로 환원될 수 있다. 본 연구에 사용된 환원제들은 $SO_2$도 효과적으로 제거시킬 수 있으므로 $NO_x$와 $SO_2$를 동시에 처리하는 것이 가능하다. 오존처리실과 흡수환원반응기로 구성된 본 연구의 2단계 공정은 모사 배기가스에 포함된 $NO_x$를 95%, $SO_2$를 100% 제거시킬 수 있었다. 환원제인 황화나트륨으로부터 발생되는 황화수소는 강염기인 수산화나트륨을 환원제와 함께 사용함으로써 방지할 수 있었다. $NO_x$와 $SO_2$를 동시에 처리하기 위한 환원제로 $Na_2SO_3$보다 $Na_2S$가 더 우수한 성능을 보여주었다.

Keywords

References

  1. Takashina, T., Honjo, S., Ukawa, N., and Iwashita, K., 'Effect of ammonium concentration on $SO_2 $ absorption in a wet limestone gypsum FGD process,' J Chem. Eng. Japan, 35, 197 - 204(2002) https://doi.org/10.1252/jcej.35.197
  2. Wark, K., Warner, C. F., and Davis, W. T., Air pollution: its origin and control, Addison-Wesley, Inc.(1999)
  3. Cooper, C. D. and Alley, F. C. Air pollution control, Waveland Press, Inc.(1994)
  4. Mok, Y. S., Dors, M., and Mizeraczyk, J., 'Effect of reaction temperature on $NO_x$ removal and formation of ammonium nitrate in nonthermal plasma process combined with selective catalytic reduction,' IEEE Trans. Plasma Sci., 32, 799-807(2004) https://doi.org/10.1109/TPS.2004.826057
  5. Koebel, M., Elsener, M., and Madia, G., 'Reaction pathways in the selective catalytic reduction process with NO and $NO_2$ at low temperatures,' Ind. Eng. Chem. Res., 40, 52 - 59(2001) https://doi.org/10.1021/ie000551y
  6. Huang, L., Hari, T., Nakajyo, K., Ozawa, S., and Matsuda, H., 'Reduction of NO by CO in a pulsed corona reactor incorporated with CuO catalyst,' J Chem. Eng. Japan, 34, 10 12 - 10 16(2001) https://doi.org/10.1252/jcej.34.1012
  7. Mok, Y. S., 'Oxidation of NO to $NO_2 $ using the ozoni- zation method to improvement of selective catalytic reduction,' J Chern. Eng. Japan, 37, 1337 -1344(2004) https://doi.org/10.1252/jcej.37.1337
  8. Kawamura, K. and Shui, V. H., 'Pilot plant experience in electron-beam treatment of iron-ore sintering flue gas and its application to coal boiler,' Radiat. Phys. Chem., 24, 117-127(1984)
  9. Tsuji, K. and Shiraishi, I., 'Combined desulfurization, denitrification and reduction of air toxics using activated coke,' Fuel, 76, 549-553(1997) https://doi.org/10.1016/S0016-2361(97)00010-0
  10. Shimizu, T., Asazuma, J., Shinkai, M., Matsunaga, S., Yamagiwa, K., and Fujiwara, N., 'Simultaneous reduction of $NO_x$, $N_2O $, $SO_2$ emissions from a fluidized bed coal combustor using alternative bed material,' J Chern. Eng. Japan, 36, 782-787(2003) https://doi.org/10.1252/jcej.36.782
  11. Lee, Y. H., Jung, W. S., Choi, Y. R., Oh, J. S., Jang, S. D., Son, Y. G., Cho, M. H., Narnkung, W., Koh, D. J., Mok, Y. S., and Chung, J. W., 'Application of pulsed corona induced plasma chemical process to an industrial incinerator,' Environ. Sci. Technol., 37, 2563 -2567 (2003) https://doi.org/10.1021/es0261123
  12. Yamamoto, T., Okubo, M., Nakao, T., and Hayakawa, K., 'Simultaneous removal of $NO_x$ , $SO_2$, and $CO_2$ at elevated temperature using a plasma-chemical hybrid process,' IEEE Trans. Ind. Appl., 38, 1168 - 1173(2002) https://doi.org/10.1109/TIA.2002.802911
  13. Kogelschatz, U, 'Dielectric barrier discharges: their history, discharge physics, and industrial applications,' Plasma Chem. Plasma Proc., 23, 1-46(2003)
  14. Mok, Y. S., Lee, H. Dors, M., and Mizeraczyk, J., 'Improvement in selective catalytic reduction of nitrogen oxides using dielectric barrier discharge,' Chem. Eng. J, 110, 79 - 85(2005) https://doi.org/10.1016/j.cej.2005.02.032
  15. Margolis, E. J., Chemical principles in calculations of ionic equilibria, 1st ed., The Macmillan Company, New York(1966)