Korean Chemical Engineering Research, Vol.49, No.1, 89-94, February, 2011
파일럿 규모 반응기에서 Hybrid SNCR-SCR 공정의 질소산화물 저감 특성
DeNOx Characteristics of Hybrid SNCR-SCR Process in a Pilot Scale Flow Reactor
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초록
하이브리드 SNCR-SCR 공정의 질소산화물 저감특성을 파일럿 규모의 흐름반응기를 이용하여 고찰하였다. SNCR 공정의 질소산화물 저감효율은 970 oC에서 80% 수준이었으며 하이브리드 SNCR-SCR 공정은 NSR = 2.0, 940 ℃에서 92%의 저감율을 보였다. SNCR 단일 공정과 비교할 때, 하이브리드 SNCR-SCR 공정은 940 ℃보다 낮은 저온영역에서 보다 효과적이었다. 암모니아 유출농도는 비교적 높은 공간속도조건에서 1 ppm 이하로 유지되었으며 요구되는 촉매양은 SCR 단일공정과 비교할 때 2/3 수준으로 감소하였다. 질소산화물 저감을 위한 하이브리드 SNCR-SCR 공정의 주요인자는 SNCR 공정에 분사되는 요소용액의 질소산화물에 대한 선택도와 생성되는 암모니아 농도로 조사되었다.
DeNOx characteristics of hybrid SNCR-SCR process have been investigated in a pilot scale flow reactor. DeNOx efficiency of SNCR reaction was about 80% at 970 ℃ and hybrid SNCR-SCR process showed 92% at 940 ℃ with NSR = 2.0. Compared to SNCR process alone, hybrid SNCR-SCR process was more effective at cool side, which is lower than 940 ℃. It should be also noted that ammonia slip from hybrid SNCR-SCR process was below 1ppm at the condition of higher space velocity and the required catalyst volume can be decreased to 2/3 of SCR process. Key factors for DeNOx efficiency of hybrid SNCR-SCR process were found to be NH3 concentration and NOx selectivity of urea injected in SNCR process.
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