摘要
利用烧结烟气循环流化床燃烧的深度净化技术,可低成本、高效地实现烧结烟气中污染物的超低排放。为了探究该技术中循环流化床密相区内焦炭还原NO的机理,以焦作无烟煤所制焦炭为实验对象,利用高温立式管式炉实验台模拟循环流化床密相区,在750℃~950℃温度下,研究烧结烟气中分别加入组分CO,CO_(2),O_(2)时,焦炭还原NO的转化率随时间变化规律。结果表明:在无O_(2)通入的反应条件下,随着反应温度的提高,焦炭对NO的还原率逐渐增加;CO的加入提升了焦炭对NO的还原率,在反应温度为900℃时,加入体积分数为0.4%的CO可最大提升17%的NO还原率;CO_(2)的加入则抑制了焦炭对NO的还原率,在反应温度为950℃时,加入体积分数为10%的CO_(2)使得NO还原率最大降低了21%;O_(2)的加入明显抑制了焦炭对NO的还原效果,在反应温度为950℃,通入气体中体积分数为13%的O_(2)时,NO的还原率下降至31%,且明显缩短了焦炭的还原时间。研究结果可为烧结烟气循环流化床燃烧技术的脱硝工艺提供参考。
The deep purification technology of sintering flue gas can be realized by applying circulating fluidized bed combustion technology.It can achieve ultra-low pollutant emissions in sintering flue gas with low cost and high efficiency.It is necessary to further explore the mechanism of NO reduction by coke in the dense phase zone.Coke made from Jiaozuo anthracite was taken as the experimental object.The reaction environment of the circulating fluidized bed dense phase zone was simulated by applying a high-temperature vertical tube furnace.The main components in sintering flue gas,CO,CO_(2),and O_(2),were added in the reactor separately,and the coke-NO reaction characteristics under the temperature range of 750℃to 950℃were discussed.The results show that if oxygen is not added to the gas inflow,the rate of NO reduction by coke increases gradually as the reaction temperature rises.The addition of CO can significantly increase the reduction rate of NO.When the reaction temperature is 900℃,the addition of volume fraction 0.4%of CO can help increase the NO reduction rate by 17%at most.While,CO_(2) can limit the reduction of NO by coke.When the reaction temperature is 950℃,the addition of volume fraction 10%CO_(2) reduces the reduction rate by_(2)1%at most.In addition,the reduction effect of coke on NO is evidently restricted with O_(2) present in the gas.When the reaction temperature is 950℃and the O_(2) volume fraction in gas is 13%,the reduction rate of NO decreases to 31%,and the reduction time of coke is significantly shortened.This work can guide the optimization of the denitrification process of sintering flue gas in the circulating fluidized bed.
作者
黄增辉
周托
王永刚
赵强
吕俊复
HUANG Zenghui;ZHOU Tuo;WANG Yonggang;ZHAO Qiang;LYU Junfu(School of Chemical and Environmental Engineering,China University of Mining and Technology(Beijing),100083 Beijing,China;Department of Energy and Power Engineering,Tsinghua University,100084 Beijing,China;College of Electrical and Power Engineering,Taiyuan University of Technology,030024 Taiyuan,China)
出处
《煤炭转化》
CAS
CSCD
北大核心
2022年第6期38-45,共8页
Coal Conversion
基金
太原市“揭榜挂帅”项目.
关键词
烧结烟气
循环流化床
焦炭
NO
还原
sintering flue gas
circulating fluidized bed
coke
NO
reduction
