Mn-Fe尖晶石协同脱硝除汞研究

发布时间：2018-05-26 08:16

本文选题：Mn-Fe尖晶石 + NH_3-SCR反应　；参考：《南京理工大学》2015年硕士论文

【摘要】：大气污染现阶段已经成为我国环境污染最为突出的问题之一,与人们健康诉求的矛盾突出,其中燃煤烟气导致的大气污染较为严重。新修订的《中华人民共和国大气污染防治法(修订草案)》重点提出了大气污染的源头治理和科技治霾,旨在改善我国大气污染现状。因此,开发出燃煤烟气协同脱硝除汞技术显得尤为重要。本论文选取铁基尖晶石作为催化剂,考察了Mn-Fe尖晶石的氨选择性催化还原氮氧化物(NH3-SCR)性能,并通过模拟L-H和E-R反应,初步探究其NH3-SCR反应机理。同时,研究气态零价汞在Mn-Fe尖晶石表面的化学吸附以及烟气组分影响其吸附零价汞的作用机制。最后,通过水洗和热再生方法,恢复Mn-Fe尖晶石的NH3-SCR反应活性,同时对化学还原的零价汞集中回收处理,实现催化剂的再生。(1) Mn-Fe尖晶石在100℃～200℃范围内,具有良好的NH3-SCR反应活性,但其抗水性不理想。在Mn-Fe尖晶石表面,吸附态的NH3以及吸附态的NO均参与NH3-SCR反应,Mn-Fe尖晶石NH3-SCR反应通过L-H机制和E-R机制两种途径还原NO。(2) Mn-Fe尖晶石在100℃～200℃范围内,具有较高的零价汞吸附容量,低温会促进零价汞的吸附。一定量的S02在其表面形成新的反应活性位,会促进零价汞的吸附。而H2O会与零价汞竞争吸附活性位,从而抑制零价汞的吸附。(3) Mn-Fe尖晶石在100℃～200℃温度范围内可以实现NH3-SCR反应和零价汞化学吸附的兼容性。通过水洗和热处理的方法,可以实现Mn-Fe尖晶石催化剂的循环再生。
[Abstract]:Air pollution has become one of the most prominent problems in China's environmental pollution, and the contradiction between the people's health demands is prominent, and the air pollution caused by coal-fired flue gas is more serious. The newly revised People's Republic of China air pollution prevention and control law (Revised Draft) focuses on the source control of air pollution and scientific and technological haze treatment. In order to improve the current situation of air pollution in China, it is very important to develop the technology of co - denitrification and removal of nitric oxide from coal-fired flue gas. In this paper, iron based spinel was selected as a catalyst to investigate the performance of ammonia selective catalytic reduction of nitrogen oxides (NH3-SCR) of Mn-Fe spinel, and the mechanism of NH3-SCR reaction was preliminarily explored by simulating the reaction of L-H and E-R. The chemical adsorption of gaseous zero valent mercury on the surface of Mn-Fe spinel and the effect of flue gas composition on the adsorption of zero valent mercury were studied. Finally, the NH3-SCR reaction activity of Mn-Fe spinel was restored by water washing and thermal regeneration. At the same time, the concentration of zero valent mercury in chemical reduction was reclaimed to achieve the regeneration of the catalyst. (1) Mn-Fe spinel In the range of 100 ~ 200 c, it has good NH3-SCR reaction activity, but its water resistance is not ideal. On the surface of Mn-Fe spinel, the adsorbed NH3 and the adsorbed NO are all involved in the NH3-SCR reaction. The Mn-Fe spinel NH3-SCR reaction reduces the NO. (2) Mn-Fe spinel in the range of 100 to 200 c through the L-H mechanism and the E-R mechanism. Higher zero valent mercury adsorption capacity, low temperature will promote the adsorption of zero valent mercury. A certain amount of S02 forms a new reactive active site on its surface, which will promote the adsorption of zero valent mercury. And H2O will compete with zero valent mercury to adsorb active sites and inhibit the adsorption of zero valent mercury. (3) Mn-Fe spinel can achieve NH3-SCR reaction within the temperature range of 100 to 200. Compatibility with zero valent mercury chemisorption. Regeneration of Mn-Fe spinel catalyst can be achieved by washing and heat treatment.
【学位授予单位】：南京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X701

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