Search / Korean Journal of Chemical Engineering
HWAHAK KONGHAK,
Vol.35, No.1, 83-89, 1997
요소용액을 이용한 배연가스내의 질소산화물 제거 연구
A Study on NOx Removal from Flue Gas by Using Urea Solution
Pilot scale 연소로에서 반응 온도, NSR(Normalized Stoichiometric Ratio), 기상 첨가제, 액상 첨가제, SO2 가스의 존재 유무가 요소용액에 의한 NOx 환원 반응에 미치는 영향을 고찰하였다. 요소용액과 암모니아에 의한 최대 NOx 환원율은 각각 970℃와 950℃에서 나타났다. NSR이 증가할수록 NOx 전환율은 증가하였으며 NSR 2.0 이상에서 일정한 전환율을 유지하였다. 알콜 첨갖제의 농도가 蝷가할수록 최적 온도와 최대 NOx 저감률은 감소하였다. 기상 첨가제(C3H8, CO)의 농도 증가에 따라 NOx 저감이 나타나는 온도영역(temperature window)은 넓어지고, 최적 반응 온도는 감소하였다. 배가스내의 SO2 가스는 NOx 저감률에는 큰 영향을 주지 않았으나 요소용액과 반응하여 760℃ 부근에서는 SO2 농도가 저감됨을 관찰하였다.
The effects of reaction temperature, NSR(Normalized Stoichiometric Ratio), gas additives, liquid additives and the presence of SO2 gas on the reduction of NOx with urea solution have been determined in a pilot scale combustor. The maximum reduction conversions of NOx by urea and ammonia exhibit at 970℃ and 950℃, respectively and NOx reduction increases with increasing NSR up to 2.0. The optimum temperature and maximum conversion of NOx reduction decrease with increasing the concentration of the alcohol additives. Temperature window for the range of NOx reduction is widened and the optimum temperature decreases with an increase in the concentration of gas additives. The presence of SO2 gases in the flue gas slightly reduces the NOx reduction and ammonium salt is formed from the reaction between SO2 and ammonia from the decomposition of urea.
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