脱硝催化剂重金属中毒及其再生技术的研究

发布时间：2018-06-03 00:52

本文选题：SCR + 催化剂　；参考：《华北电力大学》2017年硕士论文

【摘要】：选择性催化还原法(SCR)是至今脱除烟气中氮氧化物最成熟最有效的方法,催化剂作为整个SCR脱硝系统的核心,其性能的好坏直接关系到了整体脱硝效率的高低。然而催化剂长时间的使用便会造成催化剂堵塞烧结以及催化剂中毒等,在这些影响中,重金属中毒也是不可忽视的重要因素。本文着重于脱硝催化剂重金属铅、砷中毒及其再生技术的研究。脱硝催化剂铅中毒及其再生:失活部分,分别配比不同浓度的醋酸铅作为前驱体溶液浸渍于新鲜催化剂中来模拟电厂催化剂中毒,并通过搭建催化剂评价装置实验台,来测不同温度、氨氮比、负载量、铅/钒摩尔比等对脱硝性能的影响。再生部分,选取上述最佳实验反应条件和铅/钒摩尔比对脱硝性能影响较大较为明显的一组,分别通过水洗、酸洗、络合物清洗以及结合混洗的方式来进行实验研究,得出:在再生铅中毒的催化剂时,水洗是必不可少的首选方法;酸洗中醋酸有较为明显的效果;选择的几种络合物中,二乙烯三胺和三乙烯四胺的再生效果明显,相对的三乙烯四胺效果更好;混合水、醋酸以及三乙烯四胺清洗的方法效果最好,脱硝效率几乎能够达到原来新鲜催化剂的94.05%。脱硝催化剂砷中毒及其再生:失活部分,分别配比不同浓度的砷标液作为前驱体溶液浸渍于新鲜催化剂中来模拟电厂催化剂中毒,并通过搭建催化剂评价装置实验台,来测不同温度、氨氮比、负载量、砷/钒摩尔比等对脱硝性能的影响。再生部分,选取上述最佳实验反应条件和砷/钒摩尔比对脱硝性能影响较大较为明显的一组,分别通过水洗、酸洗、碱性化合物清洗以及结合混洗的方式来进行实验研究,得出:在再生砷中毒的催化剂时,水洗是必不可少的首选方法;酸洗中醋酸有较为明显的效果;选择的几种碱性化合物中,硝酸钠和碳酸钠的再生效果明显,相对的碳酸钠的效果更好;混合水、醋酸以及碳酸钠清洗的方法效果最好,脱硝效率几乎能够达到原来新鲜催化剂的93.13%。
[Abstract]:The selective catalytic reduction method is the most mature and effective method to remove nitrogen oxides from flue gas. As the core of the whole SCR denitrification system, the performance of the catalyst is directly related to the overall denitrification efficiency. However, the use of catalyst for a long time will lead to catalyst blocking and sintering and catalyst poisoning, among which heavy metal poisoning is also an important factor that can not be ignored. This paper focuses on heavy metal lead, arsenic poisoning and regeneration of denitrification catalyst. Lead poisoning of denitrification catalyst and its regeneration: deactivation part, different concentrations of lead acetate were mixed separately as precursor solution impregnated in fresh catalyst to simulate the catalyst poisoning in power plant, and the experimental bench was set up to evaluate the catalyst. The effects of different temperature, ammonia / nitrogen ratio, loading amount and lead / vanadium molar ratio on denitrification performance were measured. In the regeneration part, the optimum reaction conditions and the ratio of lead to vanadium were selected to study the effects of water washing, acid cleaning, complex cleaning and combined washing respectively on the denitrification performance. It is concluded that water washing is the first choice for regenerating lead poisoning catalyst, acetic acid has obvious effect in acid pickling, and the regeneration effect of diethylenetriamine and triethylenetetramine is obvious among the selected complexes. The effect of mixed water acetic acid and triethylenetetramine cleaning method is the best and the denitrification efficiency can almost reach 94.05 of the original fresh catalyst. Arsenic poisoning of denitrification catalyst and its regeneration: deactivation part, different concentrations of arsenic standard solution were mixed separately as precursor solution to impregnate in fresh catalyst to simulate catalyst poisoning in power plant, and the experimental bench was set up to evaluate the catalyst. The effects of different temperature, ammonia / nitrogen ratio, loading amount and molar ratio of arsenic to vanadium on denitrification performance were measured. In the regeneration part, the optimum reaction conditions and the molar ratio of arsenic to vanadium were selected to study the effects of water washing, acid washing, alkaline compound cleaning and combined washing respectively. It is concluded that water washing is the first choice in the regeneration of arsenic poisoning catalyst, acetic acid has obvious effect in acid pickling, and sodium nitrate and sodium carbonate have obvious regeneration effect in the selected basic compounds. Compared with sodium carbonate, the cleaning method of mixed water, acetic acid and sodium carbonate is the best, and the denitrification efficiency can almost reach 93.1313 of the original fresh catalyst.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X773

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