摘要:当前,全球各地有几种主要的烟气脱硝技术,其中应用广泛的技术叫做选择性催化还原法,又称SCR。对于其来说,催化剂是能够左右SCR系统整体NOx去除效果的重要组成部分。然而,当今市面上常用的SCR催化剂V2O5-WO3(MoO3)/TiO2依然存在着许多缺点。比如,(1)达到最佳催化效果时的温度仍然有300 ~ 400℃;(2)容易产生催化剂失活现象,造成这种现象的罪魁祸首是SO2与粉尘。因此,开发低温SCR催化剂, 让SCR系统置于除尘脱硫装置之后是当前低温脱硝技术研究工作中的重点。研究发现,相比于Ce、Al、Cu等金属而言,Mn、Fe及其氧化物具有优异的低温SCR活性。活性炭这一特殊材料自发现以来,便因为其巨大的比表面积,强大的吸附性能被各界关注。在催化剂领域,活性碳也得到了广泛应用。作为活性炭材料中的佼佼者,碳纳米管表现出了更为优异的性能。62067
本文以经硝酸处理后的多壁碳纳米管为载体,Mn、Fe及其氧化物为负载物,用等体积浸渍法制备一系列催化剂。考察活性组分负载量、焙烧温度等对脱硝性能的影响。通过电镜等一些表征方法对催化剂活性的影响因素进行探讨。
毕业论文关键词: 选择性催化还原;多壁碳纳米管;低温;锰;铁
Preparation and properties of low-temperature flue gas denitration catalyst
Abstract:Currently, worldwide there are several major flue gas denitrification technology, in which a wide range of technical applications, called selective catalytic reduction, also known as SCR. For it, the catalyst is capable of about SCR NOx removal system as a whole an important part. However, the market today commonly used SCR catalyst V2O5-WO3 (MoO3) / TiO2 there are still many shortcomings. For example, (1) to a temperature optimum catalytic effect when there are still 300 ~ 400 ℃; (2) prone to deactivation of the catalyst, the result of this phenomenon is the culprit SO2 and dust. Thus, after the development of low-temperature SCR catalyst, so that dust SCR system is placed in the current low-temperature flue gas desulfurization equipment denitrification technology research focus of the work. The study found that compared to Ce, Al, Cu, etc. in terms of metal, Mn, Fe oxide and has excellent low temperature SCR activity. This special activated carbon material since found it because of its huge surface area, strong adsorption properties of all walks of life are concerned. In the field of catalysts, activated carbon has been widely used. As a leader in the activated carbon material, carbon nanotubes exhibit a more excellent performance.
In this paper, multi-wall carbon nanotubes after nitric acid treatment of the carrier, Mn, Fe and oxides of loads, a series of catalysts prepared by impregnation method.The SCR activity, structure and chemical characteristics will be studied. The effects of Mn loading, calcination temperature on selective catalytic reduction (SCR) of NO with NH3 were investigated .The factors of the activity of the catalyst were discussed by means of SEM、XRD.
Keywords: SCR;Multi-wall carbon nanotubes;Mn;Fe
1 绪论 1
1.1氮氧化物污染的概况 1
1.1.1氮氧化物的来源 1
1.1.2氮氧化物的性质 1
1.1.3我国及其他国家对于氮氧化物排放要求 2
1.1.4氮氧化物的控制技术 2
1.2锰基催化剂 3
1.2.1单组份锰氧化物催化剂 4
1.2.2铁等金属氧化掺杂的多组分锰氧化物催化剂 4
1.3 碳基催化剂