竹炭协同低温等离子体脱硝机理研究

发布时间：2018-02-11 09:35

本文关键词： 低温等离子体竹炭 NO　出处：《武汉纺织大学》2017年硕士论文　论文类型：学位论文

【摘要】：大气污染防治工作面临的形势依然严峻,氮氧化合物(NOX)是大气污染物的成分之一。NOX的超标排放会导致一系列严重的问题,如环境污染、人体健康问题。因此,发展技术来控制NOX的排放已广泛的引起了关注。相比于其他去除NO的技术,低温等离子体(NTP)技术具有去除率高、占地面积少和能同时去除多种污染物等优点,因此利用低温等离子体技术来净化NO具有重要的参考价值。本文将竹炭与介质阻挡放电产生的等离子体结合起来,利用两者之间的协同作用来对燃煤烟气中NO的去除进行研究。本文主要内容和结论如下:(1)分别采用竹炭单独处理系统、NTP单独处理系统和竹炭协同NTP处理系统对NO的去除展开了研究,结果表明竹炭协同NTP处理系统对NO的净化效果是最好的。(2)竹炭单独去除NO在不同阶段去除的原理不同。实验刚开始时,竹炭的物理吸附是主要的,之后竹炭的化学吸附就发挥了重要的作用。在NTP单独处理和协同系统中,NO均被生成的活性物种分解为N2从而NO得到去除。竹炭在协同处理中有两个功能:延长气体的停留时间和有效地消耗氧物种。(3)在协同处理中,分别考察了输入的电压、O_2含量和SO_2浓度对NO净化的影响。输入电压在50 V-80 V范围内,当电压上升时,NO的脱除率相应的增加,但是继续增加反而导致效率下降。O_2含量在0-20%范围内,NO的去除效率随O_2含量的增加呈现出显著地下降趋势。SO_2的加入显著的抑制了NO的去除效率。当电压为80 V,O_2含量为8%时,在协同处理中,NO的最大去除效率可以达到74.0%。(4)对空白和经过等离子体反应后的竹炭分别进行了SEM、XRD、N2等温吸附和XPS等表征来分析反应前后竹炭的物理化学特性。等离子体的刻蚀作用使竹炭表面出现大量的小孔,导致BET比表面积和增加。竹炭是无定型碳结构,在反应后,石墨碳的相对含量是下降的,而C=O和-COO相对含量是上升的,这与协同处理去除NO的机理相符合。
[Abstract]:The situation of air pollution prevention and control work is still severe. Nitrogen oxide compounds (NOX) is one of the components of atmospheric pollutants... The development of technology to control the emission of NOX has attracted wide attention. Compared with other technologies for removing no, the low temperature plasma technology has the advantages of high removal rate, less area and the ability to remove many kinds of pollutants at the same time. Therefore, the use of low-temperature plasma technology to purify no has important reference value. In this paper, bamboo charcoal is combined with plasma produced by dielectric barrier discharge. In this paper, the main contents and conclusions of this paper are as follows: 1) using bamboo charcoal alone treatment system and bamboo charcoal NTP system to treat no, respectively. Has been studied, The results showed that bamboo charcoal combined with NTP system had the best purifying effect on no. (2) the principle of removing no by bamboo charcoal alone was different in different stages. At the beginning of the experiment, the physical adsorption of bamboo charcoal was the main one. After that, the chemical adsorption of bamboo charcoal played an important role. In the NTP treatment alone and in the synergistic system, the active species of no were decomposed into N2 and no was removed. Bamboo charcoal had two functions in the synergistic treatment: prolonging gas. Body residence time and effective oxygen consuming species. The effects of input voltage O _ 2 content and SO_2 concentration on no purification were investigated, respectively. When the input voltage was in the range of 50 V-80 V, the removal rate of no increased when the voltage increased. However, further increase resulted in a decrease in efficiency. The removal efficiency of no in the range of 0-20% was significantly decreased with the increase of the content of O _ 2. The addition of so _ 2 significantly inhibited the removal efficiency of no. When the voltage was 80 V, the content of O _ 2O _ 2 was 8%. The maximum removal efficiency of no can reach 74.0.% in the synergistic treatment) the physical and chemical properties of bamboo charcoal before and after the reaction were analyzed by means of SEMX XRDX N2 isothermal adsorption and XPS, respectively, for the blank bamboo charcoal and the bamboo charcoal after plasma reaction. A large number of pores appeared on the surface of bamboo charcoal due to the etching of the bamboos. The specific surface area and specific surface area of BET were increased. Bamboo charcoal was amorphous carbon structure, the relative content of graphite carbon decreased after the reaction, while the relative content of CfO and -COO increased, which was consistent with the mechanism of removal of no by synergistic treatment.
【学位授予单位】：武汉纺织大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X701

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