摘要
【目的】燃煤电厂排放的NO_(x)会对环境造成严重危害。因此,严格控制烟气中NO_(x)的排放有利于降低燃煤电厂对大气环境的污染,从而提升空气环境质量。目前,氨选择性催化还原法(ammonia-selective catalytic reduction,NH_(3)-SCR)是应用最为广泛的实现烟气脱硝的方法,该技术的核心是高效催化剂的设计。为提升MnO_(x)催化剂的脱硝效率,需要首先研究沉淀剂用量对其活性的影响。【方法】本研究采用共沉淀法制备了不同沉淀剂用量的MnO_(x)催化剂。并通过一系列表征测试手段,对不同沉淀剂用量的催化剂进行对比分析,探究沉淀剂用量对催化剂活性的影响机理。【结果】研究表明,以0.1 mol氨水为沉淀剂制备的0.1AH-MnO_(x)催化剂表现出最优的催化活性,在200~300℃范围内,NO转化率可达95%以上。沉淀剂用量过多加剧了催化剂的团聚现象,导致催化剂颗粒状结构增大,使得催化剂的比表面积、平均孔径和孔容减小。另外,随着沉淀剂用量的增加,催化剂的表面酸性也随之减小。这与催化剂的比表面积减小有关,而催化剂的比表面积减小导致催化剂表面的活性位点减少,不利于NH_(3)的吸附和活化,最终导致催化剂的反应活性下降。0.1AH-MnO_(x)催化剂的脱硝性能略优于0.2AH-MnO_(x)催化剂。但由于0.1AH-MnO_(x)催化剂沉淀剂用量较少,使得催化剂产量较低,导致生产成本增加。并且0.2AH-MnO_(x)与0.1AH-MnO_(x)催化剂的形貌结构、比表面积和表面酸性差异最小,同时0.2AH-MnO_(x)催化剂具有较高产量。【结论】因此,通过沉淀法制备催化剂,不仅要优化沉淀剂的种类,还要注重从沉淀剂用量和成本等方面进行综合考虑,以达到最优效果。
[Objective]The NO_(x) emissions from solid fuel combustion in coal-fired power plants can cause serious harm to the environment.Therefore,strict control of NO emissions in flue gas is beneficial for reducing the pollution of coalfired power plants to the atmospheric environment,thereby improving air quality.At present,Ammonia Selective Catalytic Reduction(NH_(3)-SCR)is the most widely used method for achieving flue gas denitrification,and the core of this technology is the design of efficient catalysts.In order to improve the denitrification efficiency of MnO_(x) catalyst,it is necessary to study the effect of precipitant dosage on its activity.[Methods]In this study,MnO_(x) catalysts with different amounts of precipitants were prepared using co precipitation method.And through a series of characterization testing methods,a comparative analysis was conducted on catalysts with different amounts of precipitants to explore the mechanism of the influence of precipitant dosage on catalyst activity.[Results]The results showed that the 0.1AH-MnO_(x) catalyst prepared with 0.1 mol ammonia water as the precipitant exhibited the best catalytic activity,with a NO conversion rate of over 95%in the range of 200-300℃.Through characterization results such as scanning electron microscopy and N_(2) adsorption desorption testing,it was found that excessive use of precipitant exacerbated the agglomeration phenomenon of the catalyst,promoted the increase of the catalyst particle structure,and reduced the specific surface area,average pore size,and pore volume of the catalyst.In addition,NH_(3)-TPD test results showed that as the amount of precipitant increased,the surface acidity of the catalyst also decreased.This is related to the decrease in the specific surface area of the catalyst,which leads to a reduction in the active sites on the catalyst surface,which is not conducive to the adsorption and activation of NH_(3),ultimately resulting in a decrease in the reaction activity of the catalyst.The denitrification performance of 0.1AH MnO_(x) catalyst is slightly better than that of 0.2AH MnO_(x) catalyst.However,due to the low amount of precipitant used in the 0.1AH-MnO_(x) catalyst,the catalyst yield is low,resulting in increased production costs.And the morphology,specific surface area,and surface acidity differences between 0.2AHMnO_(x) and 0.1AH-MnO_(x) catalysts are minimal,while the 0.2AH-MnO_(x) catalyst has a higher yield.[Conclusion]Therefore,when preparing catalysts by precipitation method,it is not only necessary to optimize the type of precipitant,but also to pay attention to comprehensive considerations from the aspects of precipitant dosage and cost,in order to achieve the optimal effect.
作者
封硕
刘欢欢
吕轩
苑鹏
王云飞
宋蕊
杨柳
李新强
FENG Shuo;LIU Huanhuan;LYU Xuan;YUAN Peng;WANG Yunfei;SONG Rui;YANG Liu;LI Xinqiang(Department of Mechanical and Electrical Engineering,Shijiazhuang Information Engineering Vocational College,Shijiazhuang 050035,Hebei China;Vertical takeoff and landing fixed wing intelligent unmanned aerial vehicle technology and application Hebei Engineering Research Center,Shijiazhuang 050035,Hebei China;Tianjin Recyclable Resources Institute,China CO.OP,Tianjin 300191;Northern Engine Research Institute of China,Tianjin 300400;Shijiazhuang Information Engineering Vocational College,Department of Agriculture,Forestry,Animal Husbandry and Medicine,Shijiazhuang 050035,Hebei China)
出处
《电力科技与环保》
2025年第5期811-821,共11页
Electric Power Technology and Environmental Protection
基金
河北省高等学校科学研究项目(ZC2025090)
关键词
催化剂
脱硝性能
沉淀剂含量
低温反应
NO转化率
catalyst
denitrification performance
precipitation agent content
low-temperature reaction
NO conversion rate
