【作者】 刘洪涛；

【导师】 张军营； 郑楚光；

【作者基本信息】 华中科技大学 ， 热能工程， 2007， 硕士

【摘要】 近年来,由于燃煤电厂的大量建立,以及煤在今后一段时间内依然是极为重要的能源,因而继SO_x、NO_x、CO₂等污染物之后,燃煤排放中重金属污染问题在世界范围内引起了广泛的关注,尤其是汞元素,会对人类的健康和生态环境产生严重的危害。如何找到即经济又高效的脱除硫硝以及重金属汞的方法,目前这方面的研究还处于探索阶段,其中利用选择性催化还原法（SCR,Selected Catalytic Reductation）对NOx脱除的高效,在通过合适的催化剂将Hg⁰氧化然后通过湿法烟气脱硫装置将NOx、SOx以及重金属汞脱除不失为一种行之有效的联合脱除方法,因此,本文就这一流程中的若干问题进行了有益的探讨。本文首先综合国内外最新资料,对燃煤烟气中汞的控制脱除技术进行归纳总结,并对选择性催化还原法脱除硝的过程中汞的氧化机理以及脱除的研究进行科学描述归纳,明确自己的研究思路。然后为了研究在SCR反应过程中不同因素对汞氧化的影响,我们利用自己制备的六种不同的催化剂（V₂O₅/SiO₂、V₂O₅/TiO₂<浸渍法制备>、V₂O₅/TiO₂<溶胶凝胶法制备>、WO₃/TiO₂、V₂O₅-WO₃/TiO₂、CuO/γ-Al₂O₃）在模拟部分烟气的情况下对汞在反应后催化氧化情况进行了实验,重点考查了氨气浓度、温度、以及不同催化剂对其形态变化的影响,然后在随后的实验中还考察了上述六种催化剂对汞的吸附性能。结果表明,HCl可以显著促进SCR反应过程中汞单质的氧化和催化剂的吸附性能,氨气浓度的增大则会使汞的氧化效率和催化剂对其的吸附效率都下降。然后,为了对不同汞催化氧化的机理进行深入探讨,我们对SCR反应过程中汞的氧化和吸附的模型进行了分析,并将模型模拟结果与实验结果进行对比分析,两者都互相符合的很好。更多还原

【Abstract】 In recent years, because of a great deal of establishment of the coal-burning power station, and in a period of time the coal is still an extremely important energy of the world. As a result of pollutant such as SO_x, NO_x, CO₂ etc., the problem of coal-burning that caused an extensive concern in the scope of the world, particularly the mercury pollution, will produce serious bane to the mankind’s health and the ecosystem environment. How to find economic and effective method to take off the pollution of the SOx,NOx and the heavy metals ? The research of this aspect is still placed on the road. Making use of the selectivity catalyst Reductation method（SCR） can reduce NOx in the coal-fired flue gas. And it is also reported that SCR system can oxidize mercury as well, so this thesis paid attention on the mercury oxidation in the SCR system.This text firstly synthesized lately data at home and abroad, then took off to the control of the mercury in the coal-fired flue gas. Then in the purpose of studying the influence of the different factor upon the mercury species’variety in the SCR process, we made use of six kinds of different catalysts （V₂O₅/SiO₂, V₂O₅/TiO₂, V₂O₅/TiO₂< sol-gel>, WO₃/TiO₂, V₂O₅-WO₃/TiO₂, CuO/γ-Al₂O₃） in the experiments. The point is to investigate the influence on mercury oxidation and catalysts’adsorbtion of ammonia concentration, SCR temperature, and different catalysts, and in the addition, we carry on an evaluation to the different catalysts.Then, in order to carry on the deep discussion for the mercury catalysis oxidized mechanism, we analyzed some mercury catalysis oxidized and adsorbed model in SCR process, and compare the results with experimental results. The final result shows that they match well.更多还原