含铈材料烟气脱汞性能研究进展  

Research progress on Hg removal performance of Ce-containing materials

作　　者：吕强[1] 关昱 刘银河[1] LYU Qiang;GUAN Yu;LIU Yinhe(School of Energy and Power Engineering,Xi′an Jiaotong University,Xi′an710049,China)

机构地区：[1]西安交通大学能源与动力工程学院,陕西西安710049

出　　处：《洁净煤技术》2022年第8期69-83,共15页Clean Coal Technology

基　　金：陕西省自然科学基金资助项目(2022JQ-114)。

摘　　要：控制燃煤锅炉的汞排放是我国减少重金属汞排放的关键,研发高效低成本的脱汞材料对燃煤烟气汞污染控制具有重要意义。铈是丰度最高的稀土元素,其氧化物具有无毒性、低成本等特点,且铈氧化物具有优异的储氧能力和氧化还原反应活性,使其在烟气脱汞领域具有较大的应用潜力。综述了含铈材料在烟气脱汞领域的最新研究进展,分析了含铈材料各种制备方法的特点,并指出其分子模型构建的关键;介绍了含铈材料的脱汞性能,探讨了炭基材料和非炭基材料的发展现状;论述了主要燃煤烟气组分对含铈材料脱汞性能的影响,重点关注了SO_(2)、H_(2)O、NO、HCl、NH_(3)和O_(2)等对单质汞脱除的促进或抑制机理;最后对含铈脱汞材料的研究进行展望。研究表明,浸渍法制备含铈材料简单易得,但活性成分均匀性难以保证,共沉淀法不适用于负载量低的样品,溶胶凝胶法可实现分子水平的均匀混合,模板法、水热法和溶剂热法制得的样品分散性好,火焰法则有待进一步发展,含铈材料分子模型的构建需考虑铈含量、铈分散状态;物理吸附、化学吸附和催化氧化对含铈材料脱汞均有贡献;低浓度SO_(2)有助于汞氧化,但高浓度SO_(2)会在铈氧化物表面与汞竞争吸附;相比其他材料,含铈材料的抗H_(2)O性能更佳;NO可与含铈材料中的氧反应生成NO_(2)促进汞氧化;向含铈材料中添加CuO可缓解NH_(3)对脱汞的不利影响;HCl与O_(2)对脱汞效率的促进程度受铈氧化物含量影响。在已有研究基础上,含铈脱汞材料在商业化应用前仍有以下问题亟待解决:汞与烟气组分在含铈多元金属材料表面的竞争机制或协同脱除机理,含铈材料的环境影响,含铈材料在实际烟气中的脱汞性能,脱汞反应器及脱汞装置的设计及优化,含铈脱汞材料的技术经济性研究。基于现有试验和模拟研究,总结了含铈材料的脱汞性能及Controlling mercury emission from coal-fired boilers is the top priority of mercury reduction in China.It is of great significance to develop efficient and low-cost mercury removal materials for mercury pollution control from coal-fired flue gas.Ce is the most abundant rare earth element,and cerium oxide has the virtues of non-toxicity and relatively inexpensive.More importantly,excellent oxygen storage capacity and redox reaction activity of cerium oxide make it have great application potential in the field of mercury removal.The latest research progress of cerium-containing materials in removing mercury from flue gas was reviewed.The various preparation methods of cerium-containing materials were analyzed,and the key points for building the molecular model of cerium-containing catalysts or adsorbents were emphasized.The mercury removal performance of cerium-containing materials was introduced,and the direction for future study on carbon-based materials and non-carbon-based materials were discussed.The influences of the main flue gas components on the mercury removal performance of cerium-containing materials were discussed in detail.The promotion or inhibition mechanisms of SO_(2)、H_(2)O、NO、HCl、NH_(3) and O_(2) on the elemental mercury removal were summarized.Finally,the prospects of the research on cerium-containing mercury removal materials were proposed.The results show that the preparation of cerium containing materials by impregnation is simple,but the uniformity of the active components is hard to achieve.The coprecipitation method is unsuitable for low loading samples.The sol-gel method can ensure uniform mixing at the molecular level.The materials prepared through template method,hydrothermal method and solvothermal method have good dispersion characteristics,while the flame synthesized catalysts still need further development.The content of cerium and the cerium dispersion state should be considered in the construction of cerium-containing materials molecular model.Physisorption,chemisorption a

关 键 词：燃煤烟气 汞污染 铈氧化物 脱汞技术 烟气组分 

分 类 号：X511[环境科学与工程—环境工程]