Transactions of the Korean Society of Automotive Engineers (한국자동차공학회논문집)

The Korean Society of Automotive Engineers (한국자동차공학회)
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Modeling of $NH_3$-SCR Diesel $NO_x$ Reduction and Effects of $NO_2/NO_x,\;NH_3$/NO Ratios on the De-$NO_x$ Efficiency

$NH_3$-SCR 방법에 의한 디젤기관의 $NO_x$ 저감과정의 모델링 및 $NO_2/NO_x,\;NH_3$/NO비에 따른 저감효율 변화 해석

  • 정승채 (연세대학교 기계공학과 대학원) ;
  • 윤웅섭 (연세대학교 기계공학과)
  • Published : 2008.05.01
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Abstract

A mathematical modeling of $NO_x$ reduction in $NH_3$-SCR process is conducted. The present deterministic model solves one-dimensional conservation equations of mass and species concentrations for channel flows and the catalytic reaction. NO and NO_2$ reactions by the vanadium catalyst in the presence of $NH_3$ are calculated with the rate expressions of Langmuir-Hinshelwood scheme. The modeling was validated with extensive empirical data regarding $NO_x$ reduction efficiency. Analysis of De-$NO_x$ sensitivity conducted with regard to oxygen and water yielded highly accurate prediction over a wide range of $NO_2/NO_x$ ratios from 0 to 1 in a temperature range of $200^{\circ}C{\sim}550^{\circ}C$. The $NO_x$ reduction largely depends on $NO_2/NO_x$ ratio at temperatures lower than $300^{\circ}C$. NO reduction efficiency is significantly augmented with increasing in $NH_3$/NO ratio at higher temperatures, whereas rather insensitive to the $NH_3$/NO ratio at lower temperatures.

Keywords

References

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