摘要
由于燃机烟气具有浓度低、NO2及H2O含量高等特点,传统催化剂难以直接用于其脱硝处理。文章针对高钒SCR脱硝催化剂低温活性好、宽温域、抗水性好等优势,开展高钒催化剂性能与反应机理的研究。采用浸渍法制备了一系列不同钒、钼添加量的催化剂。结果表明钒、钼的添加量(质量分数)分别为3%和4%时,催化剂具有最佳的脱硝性能,在220~440℃保持95%以上的脱硝效率。该催化剂具有较好的抗水性,O2浓度对催化性能的影响不大,NOx浓度过高或过低时,脱硝效率有所降低,烟气中适量NO2的存在对催化性能有促进作用。表征结果显示,该催化剂具有较大的比表面积,活性组分均匀分散,Bronsted酸和Lewis酸位显著增加。
Due to the low concentration of flue gas and high content of NO2 and H2O, traditional catalysts are difficult to be directly used for the denitrification treatment of gas turbine flue gas. Considering the advantages of catalyst with high content of vanadium, such as excellent low temperature activity, wide temperature range and strong water resistance, the performance and reaction mechanism of high vanadium catalysts were studied. A series of V-Mo/TiO2 catalysts with different amounts of V and Mo for selective catalyst reduction(SCR) of NO by NH3 were prepared by the impregnation method. The results showed that when V and Mo were added at 3 wt.% and 4 wt.%, respectively, the catalyst exhibited the highest catalytic activity and NO conversion could stabilize over 95% at the temperature window of 220~440 ℃. The catalyst exhibited strong water resistance, and O2 concentration had little effect on the catalytic performance. When the NOX concentration was too high or too low, the NO conversion was reduced, and the presence of an appropriate amount of NO2 in the flue gas could promote the catalytic performance. Characterization results indicated such optional catalyst had a larger specific surface area as well as a better dispersion of the active component. At the same time, Br?nsted acid and Lewis acid sites of the catalyst increased significantly.
作者
周凯
吴鹏
庄柯
王玲
王圣
张亚平
沈凯
ZHOU Kai;WU Peng;ZHUANG Ke;WANG Ling;WANG Sheng;ZHANG Yaping;SHEN Kai(State Power Environmental Protection Research Institute,Nanjing 210031,China;Key Laboratory for Energy Thermal Conversion and Control of Ministry of Education,School of Energy and Environment,Southeast University,Nanjing 210096,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2019年第8期162-168,共7页
Environmental Science & Technology
基金
国家重点研发计划(2017YFB0603201)
江苏省重点研发计划项目(BE2017716)
环保公益性行业科研项目(2016YFC0208102)
关键词
燃气轮机
SCR
高钒催化剂
钼改性
gas turbine
SCR
high vanadium catalyst
Mo modification
