SCR气氛条件下Ce基催化剂汞氧化性能与机制  

Mercury oxidation performance and mechanism of Ce-based catalyst under SCR flue gas

作　　者：张庚 何川[1,2] 吴迅 唐荣富 兰小洪[3] 张丹平 赵丽娟[3] 吴国勋 李乐田 陈兴 李昂 李国良 ZHANG Geng;HE Chuan;WU Xun;TANG Rongfu;LAN Xiaohong;ZHANG Danping;ZHAO Lijuan;WU Guoxun;LI Letian;CHEN Xing;LI Ang;LI Guoliang(Xi’an Thermal Power Research Institute Co.Ltd.,Xi′an 710054,China;Suzhou TPRI Ener&Enviro Tech Co.Ltd.,Suzhou 215153,China;Huaneng Luohuang Generation Co.Ltd.,Chongqing 402283,China;School of Energy and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]西安热工研究院有限公司,西安710054 [2]苏州西热节能环保技术有限公司,苏州215153 [3]华能重庆珞璜发电有限责任公司,重庆402283 [4]北京科技大学能源与环境工程学院,北京100083

出　　处：《环境工程学报》2025年第2期491-499,共9页Chinese Journal of Environmental Engineering

基　　金：华能集团科技项目(HNKJ23-H39);国家自然科学青年基金资助项目(52200121)。

摘　　要：燃煤电厂和工业锅炉为我国最大的大气汞固定排放源,我国采用多种污控措施协同控制技术降低燃煤行业烟气汞排放。该控制技术的关键是通过协同脱硝脱汞催化剂将Hg^(0)氧化为Hg^(2+),继而被湿法脱硫技术吸收捕集。针对Ce基催化剂在SCR组分下汞氧化率低和抗硫性差的问题,本研究采用浸渍方法以CeO_(2)为活性位点、TiO_(2)为载体、WO_(3)和CuO为改性剂,制备了Ce5Ti、Ce5W9Ti、Cu5Ce5W9Ti 3种Ce基催化剂,并探究了各种催化剂在不同烟气条件下汞氧化性能。Ce5Ti和Ce5W9Ti催化剂在中温(250~400℃)条件下表现出较高的汞催化氧化效率,分别达到58.4%~69.1%和68.8%~81.3%,但在低温(100~200℃)条件下的汞氧化率较低(低于53.1%和62.5%)。CuO的掺杂提高了Cu5Ce5W9Ti催化剂在低温区间(100~200℃)的汞氧化率,可达到76.3%~85.5%。WO_(3)的掺杂提高了Ce5W9Ti催化剂在SCR烟气组分下的汞氧化率,依然可达到62.4%以上;CuO的掺杂提高了Cu5Ce5W9Ti催化剂在SCR和SCR+SO_(2)烟气组分下汞氧化率,分别达到81.3%和78.8%。CuO、WO_(3)引入使Cu5Ce5W9Ti表面形成强弱碱性多反应活性区域,分离NH3、SO_(2)和Hg^(0)吸附反应区域,降低NH3、SO_(2)和Hg^(0)的竞争吸附,提高催化剂Hg^(0)氧化能力和抗硫性能,为多污控措施协同控制汞排放提供关键催化理论。Coal-fired power plants and industrial boilers are the largest sources of atmospheric mercury emission in China.Multi pollution synergistic control measures are adopted to reduce flue gas mercury emission in coal-fired industries.The key of synergistic control technology is to oxidizing Hg^(0) to Hg^(2+)through synergistical denitrification and mercury removal catalyst(SCR catalyst),and be captured by the wet desulfurization technology.In view of the low mercury oxidation efficiency and poor sulfur resistance of Cebased SCR catalysts,three Ce-based catalysts of Ce5Ti,Ce5W9Ti and Cu5Ce5W9Ti were prepared by the impregnation method with CeO_(2) as the active site,TiO_(2) as the carrier,and WO_(3) and CuO as the modifying agent.The mercury oxidation efficiency of various catalysts were investigated at different flue gas components.Ce5Ti and Ce5W9Ti catalysts showed higher mercury oxidation efficiency(58.4%~69.1%and 68.8%~81.3%,respectively)in the middle temperature range(250~400℃),but lower mercury oxidation efficiency(lower than 53.1%and 62.5%)in the low temperature range(100~200℃).CuO doping improved the mercury oxidation efficiency(76.3%~85.5%)of Cu5Ce5W9Ti catalyst in the low temperature range(100~200℃);WO_(3) doping increased the mercury efficiency of Ce5W9Ti catalyst to 62.4%under SCR flue gas component.The mercury oxidation efficiencies of Cu5Ce5W9Ti in SCR and SCR+SO_(2) flue gases increased to 81.3%and 78.8%,respectively.The introduction of CuO and WO_(3) to Cu5Ce5W9Ti catalyst led to form strong and weak alkaline multi-reactive zones on its surface,separate NH3,SO_(2) and Hg^(0) adsorption zones,reduce their competitive adsorption and improve the Hg^(0) oxidation capacity and sulfur resistance of catalysts.This study provides key technical theories for the mercury emission reduction of multi-pollution synergistic control measures.

关 键 词：催化剂 CeO_(2) 汞氧化 酸碱性 协同控制 

分 类 号：X705[环境科学与工程—环境工程]