摘要
利用一维热态实验炉模拟煤粉燃烧的快速升温条件,考察烟煤添加选铁尾矿后在不同温度(750℃,800℃,850℃,900℃,950℃)、不同过量空气系数(0.8,0.9,1.0,1.1,1.2)以及不同选铁尾矿添加量(质量分数为1%,3%,5%)的条件下燃烧产生的NO_(x)的排放特性。结果表明:在750℃~950℃范围内,选铁尾矿存在一个合适的脱硝窗口即800℃~900℃;且选铁尾矿的脱硝活性随着过量空气系数的增加而增加,当过量空气系数为1.2时表现出最好的脱硝活性;选铁尾矿添加量对于NO_(x)脱除率的影响因温度不同表现出不同的结果,在750℃下选铁尾矿的NO_(x)脱除率随着其添加量的增加而增加,在800℃~950℃下3%为最佳添加量。通过对选铁尾矿的XRD分析以及Fe_(2)O_(3)的TG-MS分析得出,选铁尾矿具有催化脱硝活性的一个原因是选铁尾矿内的铁白云石受热分解后生成Fe_(2)O_(3),CO还原NO的催化还原过程主要是通过Fe_(2)O_(3)与FeO的氧化还原循环完成的。
The rapid heating conditions of pulverized coal combustion were realized by using a one-dimensional thermal experimental furnace to investigate the emission characteristics of NO_(x) from bituminous coal combustion at different temperatures(750℃,800℃,850℃,900℃,950℃),different excess air coefficients(0.8,0.9,1.0,1.1,1.2),and different iron beneficiation tailings addition amounts(mass fraction is 1%,3%.5%,respectively).The results show that in the range of 750℃-950℃,the appropriate denitrification temperature is between 800℃to 900℃for iron beneficiation tailings,and the denitrification activity of iron beneficiation tailings increases with the increase of excess air coefficient.The optimum denitrification performance is presented at the excess air coefficient of 1.2.The effect of iron beneficiation tailings addition on the NO_(x) removal rate demonstrates different results depending on the temperature.At 750℃,the NO_(x) removal rate increases with the increase of iron beneficiation tailings addition.While,the optimum addition amount of iron beneficiation tailings is 3%at 800℃-950℃.Through XRD analysis of iron beneficiation tailings and TG-MS analysis of Fe_(2)O_(3),it is concluded that one of the reasons for the catalytic denitrification activity of iron beneficiation tailings is that the iron dolomite in iron beneficiation tailings is thermally decomposed to produce Fe_(2)O_(3),and the catalytic reduction process for CO reduction of NO is mainly accomplished through the redox cycle of Fe_(2)O_(3) and FeO.
作者
张钊
戚瑞
徐亚欣
龚志军
武文斐
ZHANG Zhao;QI Rui;XU Yaxin;GONG Zhijun;WU Wenfei(School of Energy and Environment,Inner Mongolia University of Science and Technology,014010 Baotou,China;Collaborative Innovation Center of Integrated Exploitation of Bayan Obo Multi-metal Resources,Inner Mongolia University of Science and Technology,014010 Baotou,China;Key Laboratory of Efficient and Clean Combustion,Inner Mongolia Autonomous Region,014010 Baotou,China)
出处
《煤炭转化》
CAS
CSCD
北大核心
2023年第2期92-98,共7页
Coal Conversion
基金
内蒙古自治区自然科学基金项目(2019ZD13,2020MS05045).
关键词
选铁尾矿
煤粉燃烧
催化脱硝
CO还原NO
氧化还原循环
iron beneficiation tailings
pulverized coal combustion
catalytic denitrification
NO reduction by CO
redox cycle
