Journal of Korean Society of Environmental Engineers (대한환경공학회지)

Korean Society of Environmental Engineers (대한환경공학회)
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Effect of Ozone Injection into Exhaust Gas on Catalytic Reduction of Nitrogen Oxides

촉매 공정의 배기가스 질소산화물 저감 성능에 미치는 오존주입의 영향

  • Yun, Eun-Young (Department of Chemical Engineering & Clean Technology, Cheju National University) ;
  • Mok, Young-Sun (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)
  • 윤은영 (제주대학교 청정화학공학과) ;
  • 목영선 (제주대학교 청정화학공학과) ;
  • 신동남 (포항산업과학연구원 환경연구팀) ;
  • 고동준 (포항산업과학연구원 환경연구팀) ;
  • 김경태 (포항산업과학연구원 환경연구팀)
  • Published : 2005.03.31
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Abstract

The ozone injection method was proposed to improve the catalytic process for the removal of nitrogen oxides ($NO_x$). Nitric oxide (NO) in the exhaust gas was first oxidized to nitrogen dioxide ($NO_2$) by ozone produced by dielectric barrier discharge, and then the exhaust gas containing the mixture of NO and $NO_2$ was directed to the catalytic reactor where both NO and $NO_2$ were reduced to $N_2$ in the presence of ammonia as the reducing agent. A commercially available $V_2O_5-WO_3/TiO_2$ catalyst was used as the catalytic reactor. The $NO_2$ content in the mixture of NO and $NO_2$ was changed by the amount of ozone added the exhaust gas. The effect of reaction temperature, initial $NO_x$ concentration, feed gas flow rate, and ammonia concentration on the removal of $NO_x$ at various $NO_2$ contents was examined and discussed. The increase in the content of $NO_2$ by the ozone injection remarkably improved the performance of the catalytic reactor, especially at low temperatures. The present ozone injection method appears to be promising for the improvement of the catalytic reduction of $NO_x$.

본 연구에서는 촉매공정의 질소산화물 제거 성능을 향상시키기 위하여 배기가스에 오존을 주입하였다. 배기가스에 오존을 주입하면 배기가스에 포함되어 있는 NO의 일부가 $NO_2$로 빠르게 산화되며, NO와 $NO_2$ 혼합물은 촉매반응기에서 $N_2$로 환원된다. 오존의 발생을 위해 유전체 장벽 방전 반응기가 사용되었고 촉매로는 상용 $V_2O_5-WO_3/TiO_2$ 촉매가 사용되었다. 질소산화물의 환원제는 암모니아였다. 촉매반응기 전단의 $NO_2$ 함량은 오존 주입량에 의해 변화될 수 있었으며, $NO_2$ 함량 변화가 촉매의 질소산화물 저감성능에 미치는 영향에 대해 살펴보았다. $NO_2$ 함량이 촉매반응기의 성능에 미치는 영향은 다양한 조건에서 수행되었는데, 주요 변수로 선정한 것은 반응온도, 초기 $NO_x$ 농도, 암모니아 농도, 그리고 배기가스 유량이었다. 오존주입에 의한 $NO_2$ 함량 증가는 촉매공정의 질소산화물 제거 성능을 크게 향상시킬 수 있었으며, 이러한 성능 향상 효과는 반응온도가 낮을수록 두드러졌다. 본 연구의 오존 주입 방법은 기존 촉매 공정의 개선에 크게 유용할 것으로 판단된다.

Keywords

References

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