화학공학소재연구정보센터
HWAHAK KONGHAK, Vol.41, No.1, 86-92, February, 2003
가압유동층연소로에서 국내무연탄의 황산화물 배출특성
The Characteristics of SO2 Emission with Korean Anthracite in a Pressurized Fluidized Bed Combustor
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초록
본 연구는 가압유동층연소로에서 국내 무연탄을 연소함에 있어서 SO2 배출농도에 대하여 고찰하였다. Bench scale PFBC에서 석탄을 연소하는 동안에 탈황제로 석회석을 사용하였으며, 배가스의 배출특성을 조사함에 있어서 SO2의 제어에 주안점을 두었다. 석탄은 강원도 태백지역에서 채탄된 무연탄이고, 석회석은 강원도 삼척지역에서 얻은 것이다. 실험장치는 층 직경 0.17 m, freeboard 직경 0.25 m이고, 총 높이가 5 m로 이루어졌다. 실험은 운전압력(1-6 atm), 운전온도(850-950 ℃), 과잉공기(10-30%), Ca/S 몰비(0.8-4.8)의 조건으로 수행하였다. 결과적으로 최대 탈황율을 보인 층(bed)온도는 1, 2 기압일 때 850 ℃, 4 기압일 때 900 ℃, 6 기압일 때 950 ℃로 나타났다. 또 탈황율은 모든 실험조건에서 운전압력, Ca/S 몰비, 과잉공기가 증가함에 따라 증가하였다. 국내무연탄의 가압유동층연소시 안정적인 SO2의 배출을 위하여 각각의 운전압력에서 적정한 Ca/S 몰비는 2 기압 이하일 때 Ca/S≥4.8, 4 기압일 때 Ca/S=4.8, 6 기압 이상일 때 Ca/S≤4.8를 보였다.
This study was to investigate the SO2 emission with Korean anthracite in a PFBC (Pressurized Fluidized Bed Combustor). This work focuses on the control of SO2, one of the severe air pollutants in flue gas, emission characteristics by injecting sorbent during the combustion of coal in a bench scale PFBC. The coal and limestone used in this work were Taeback anthracite and Samchuck limestone, respectively, in Korea. The effects of operation parameters such as pressure (1-6 atm), bed temperature (850-950 ℃), excess air ratio (10-30%) and Ca/S mole ratio (0.8-4.8) on desulfurization was investigated in PFBC (0.17 m of bed diameter, 0.25 m of freeboard diameter and 5.0 m height). The bed temperature showing maximum sulfur capture increased from 850 ℃ at 1 and 2 atm. to 950 ℃ at 6 atm. with 10% of excess air ratio. Sulfur capture increased as excess air ratio increased at all experimental condition. Both the sulfur capture and the temperature showing maximum sulfur capture increased as operation pressure increased. It was recognized that Ca/S mole ratio higher than 4.8 was needed below 2 atm. and lower Ca/S mole ratio than 4.8 was needed at 4 and 6 atm. for the stable SO2 emission in combustion of Korean anthracite.
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