摘要
CO作为大气主要污染物之一,来源较为广泛。工业炉窑、冶金工业以及机动车尾气排放等均会造成CO大量排放,污染环境。催化燃烧技术是公认的有效限制并消除CO的主流技术,可通过引入催化剂的方式实现CO低温高效转化,已在汽车尾气排放、CO优先氧化等低温催化氧化领域形成了产业化应用,且效果显著。Cu-Ce复合氧化物催化剂具有低温高效、寿命长且廉价等优点,成为应用于CO催化燃烧的首选催化剂。综述近年来Cu-Ce体系催化剂上CO催化燃烧反应的研究进展,列举了不同的催化剂制备方法,概括了Cu-Ce催化剂的结构形貌-性能关系与载体-活性组分的强相互作用规律(尺寸效应、界面效应),分析了基于表征技术、原位试验与反应动力学等方法得到的不同反应路径之间的差异,总结出CO催化燃烧微观反应机理。同时根据不同工业废气中CO浓度变化特点,介绍了中国科学院力学研究所高效洁净燃烧课题组近年的相关工作进展,最后对CO催化燃烧反应研究未来发展方向进行了展望。以转炉炼钢过程中产生的转炉放散煤气(CO≤35%)为例,设计制备出低温高效CuCe 0.75 Zr 0.25 O y催化剂,并进一步合成工业级蜂窝陶瓷催化剂,提出了CO自持催化燃烧技术,探究得到宽CO浓度范围(1%~20%)条件下的CO催化燃烧反应规律(诱导阶段、热飞温及热自持阶段),确定了较详细的CO催化燃烧反应路径(M-K和L-H机理)与稳燃机制(贫燃极限、稳燃温度场、换热特性),为转炉放散煤气从所需燃气引燃到自身能量回收利用的双向节能提供切实可行的技术方案。未来CO催化燃烧反应机理研究可从新型高效纳米Cu-Ce催化剂出发,寻找精细的形貌可控催化剂制备方法与规模化生产技术,制得活性位原子利用率高、持久高效的催化剂,采用先进的原位表征试验技术与理论模拟计算方法,深入研究催化剂载体-活性组分相互作用演化规律,开展CO催化燃烧吸附-反应-脱附过程的定性定量研究,以丰富CO催化燃烧安全控制理论,考察长时间复杂烟气环境下催化剂的各项性能,促进工业节能减排的发展。
CO,as one of the main atmospheric pollutants,comes from industrial furnaces,metallurgical industry and exhaust emission of motor vehicle,causing huge emissions of CO and serious environmental pollution.Currently,the catalytic combustion technology is an effective the mainstream technology to effectively limit and eliminate CO,which can realize low-temperature and high-efficiency conversion of CO by introducing catalyst.It has formed industrial application in low-temperature catalytic oxidation fields such as automobile exhaust emission and preferential oxidation of CO,and the effect is remarkable.The Cu-Ce complex oxide catalysts have attracted many researchers attentions due to its advantages of high efficiency at low temperature,long life and low cost,and widely used in the CO catalytic combustion.The research progress of CO catalytic combustion over Cu-Ce catalyst in recent years was reviewed,and the preparation methods,structure-activity relationship and carrier-active component interaction of Cu-Ce catalyst were summed up here.Based on the characterization techniques,in situ experiments and reaction kinetics models,the difference between various reaction pathways were discussed and the micro reaction mechanism of CO catalytic combustion was summarized.At the same time,according to the variation characteristics of CO concentration in different industrial waste gases,the relevant work progress in recent years carried out by high efficiency and clean combustion team from Institute of Mechanics,Chinese Academy of Science was introduced.Finally,the future development direction of CO catalytic combustion reaction is prospected.Taking the converter off gas(CO≤35%)produced during converter steelmaking process,the CO self-sustained catalytic combustion technology was proposed based on the CuCe 0.75 Zr 0.25 O y and industrial honeycomb ceramic catalyst catalyst,and the rule of CO self-sustained combustion under a wide range of CO concentration(induction,flying hot temperature and self-sustaining stages),reaction paths(M-K and L-H mechanisms)and stable-combustion region(lean burn limit,steady temperature field and heat transfer characteristics)were established,which provided a feasible technical solution to realize two-way energy-saving between the loss of converter gas from the gas ignition and its own energy recycling.The future research direction is also discussed:the research on CO catalytic combustion reaction mechanism can be further studied by the new efficient nano Cu-Ce catalyst,including a high utilization of active atom,lasting and efficient catalyst via a fine morphology of catalyst preparation method and large-scale production technology.It′s good for investigating evolution rule of the support-active component interaction via advanced in situ characterization technology,simulating calculation method,and the quantitative study of CO adsorption-reaction-desorption reaction process is carried out.The catalyst is also encouraged to extend from laboratory to practical industrial application,in order to investigate various properties of catalyst for complex flue gas environment for a long time using.This analysis can be expected to enrich safety control theory of CO catalytic combustion and promote the development of energy saving and emission reduction.
作者
康润宁
魏小林
宾峰
王子兵
KANG Running;WEI Xiaolin;BIN Feng;WANG Zibing(State Key Laboratory of High-Temperature Gas Dynamics,Institute of Mechanics,Chinese Academy of Science,Beijing 100190,China;School of Engineering Science,University of Chinese Academy of Sciences,Beijing 100049,China;Dalian National Laboratory for Clean Energy,Chinese Academy of Science,Dalian 116023,China;College of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,China)
出处
《洁净煤技术》
CAS
2020年第5期111-118,共8页
Clean Coal Technology
基金
国家自然科学基金面上资助项目(51776216)
国家重点研发计划资助项目(2016YFB0601501)
中国科学院战略性先导科技专项资助项目(XDA21040500)。
关键词
Cu-Ce催化剂
CO
催化燃烧
构效关系
反应机理
Cu-Ce catalyst
CO
catalytic combustion
structure-activity relationship
reaction mechanism
