纳米陶瓷负载钒系催化剂的制备与脱硝特性的实验研究

发布时间：2018-06-15 10:17

本文选题：脱硝 + NH_3-SCR　；参考：《华北电力大学》2015年硕士论文

【摘要】：近年来我国经济迅猛发展,但是大气污染日益严重,已经严重影响人们的正常生活。氮氧化物是大气污染的主要组成部分之一,也是形成雾霾的主要原因。燃煤电厂是主要的氮氧化物排放源,燃煤电厂采用烟气脱硝技术已经成为我国火电发展的必然选择。目前选择性催化NH3-SCR法脱硝以其工艺可靠、效率高的优势已成为火力发电机组脱硝的主流技术。但是在实际运行NH3-SCR脱硝中,还是存在一些问题比如催化剂烧结、催化剂积灰、硫酸铵附着催化剂等,这些问题都给火电厂的脱硝效率带来了很大影响。随着对选择性催化NH3-SCR脱硝的深入研究,发现载体性能的不同会给相应催化剂脱硝性能带来较大的差异。本文利用水解法制备了纳米Ti02,通过XRD、SEM等表征方法研究了纳米Ti02随着温度升高逐渐由锐钛矿转变为金红石的实验过程中,晶相和形貌尺寸的具体变化规律。利用熔盐法制备纳米陶瓷粉体的技术,合成了一种具有多孔结构的纳米Bi3NbTiO9陶瓷粉体。通过对合成的Bi3NbTiO9粉体TG-DTA、XRD、SEM、BET等表征结果的分析,来研究Bi3NbTiO9粉体的材料性能。将这两种材料通过浸渍法分别制成了传统V2O5-WO3/TiO2脱硝催化剂和新型V2O5-WO3/Bi3NbTiO9脱硝催化剂。利用自主搭建的脱硝试验台,通过催化剂脱硝性能评价实验,对比了两种催化剂在不同工况下脱硝性能的差异.发现新型V2O5-WO3/Bi3NbTiO9脱硝催化剂比V205-WO3/TiO2脱硝催化剂,在脱硝催化剂温度窗口宽度、空速对脱硝催化剂催化活性的影响、氨氮比对脱硝催化剂的影响、催化剂比表面积的大小等脱硝性能指标上具有较为明显的优势；但是在抗SO2方面,V2O5-WO3/TiO2脱硝催化剂有更大的优势。结合钒系催化剂脱硝反应机理,发现Bi3NbTiO9粉体强大的物理吸附能力是新型催化剂脱硝性能优于传统催化剂的主要原因。
[Abstract]:In recent years, China's economy has developed rapidly, but air pollution is becoming more and more serious, which has seriously affected people's normal life. Nitrogen oxide is one of the main components of air pollution and the main cause of smog. Coal-fired power plant is the main nitrogen oxide emission source. Flue gas denitrification technology has become the inevitable choice of thermal power development in China. At present, selective catalytic NH _ 3-SCR denitrification has become the mainstream technology of thermal power unit denitrification because of its reliable process and high efficiency. However, in the actual operation of NH3-SCR denitrification, there are still some problems, such as catalyst sintering, catalyst ash deposition, ammonium sulfate adhesion catalyst and so on. These problems have a great impact on the denitrification efficiency of thermal power plants. With the in-depth study of selective catalytic NH _ 3-SCR denitrification, it is found that the different performance of the support will bring great difference to the denitrification performance of the corresponding catalyst. In this paper, nanocrystalline Ti02 was prepared by hydrolysis method. The crystal phase and morphology of nano-Ti02 changed from anatase to rutile with the increase of temperature by means of XRD SEM and other characterization methods. A kind of nano-Bi3NbTiO9 ceramic powder with porous structure was synthesized by molten salt method. The properties of Bi3NbTiO9 powders were studied by analyzing the characterization results of the synthesized Bi3NbTiO9 powders. The traditional V _ 2O _ 5-WO3 / TIO _ 2 denitrification catalyst and the new V _ 2O _ 5-WO3 / Bi _ 3NbTiO _ 9 denitrification catalyst were prepared by impregnation method. The denitrification performance of the two catalysts under different operating conditions was compared by using an independent denitrification test rig and an evaluation experiment on the denitrification performance of the catalyst. It was found that a new type of V _ 2O _ 5-WO _ 3 / Bi _ 3NbTiO _ 9 denitrification catalyst was better than that of V _ 205-WO3 / TIO _ 2 denitrification catalyst. The effect of temperature window width and space velocity on the catalytic activity of denitrification catalyst and the effect of ammonia to nitrogen ratio on denitrification catalyst were found. The specific surface area of the catalyst has obvious advantages in denitrification performance, but the V _ 2O _ 5-WO3 / TIO _ 2 denitrification catalyst has more advantages in SO2 resistance. Combined with the mechanism of denitrification of vanadium catalyst, it is found that the strong physical adsorption ability of Bi3NbTiO9 powder is the main reason that the new catalyst has better denitrification performance than the traditional 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】：2015
【分类号】：TQ426;X773

【二级参考文献】