摘要：随着社会经济的不断发展,钢铁冶炼、火力发电、汽车尾气及垃圾焚烧等都会产生各种危害生态环境和人类健康的气体,其中氮氧化物(NOx)是较难治理又危害极大的气态污染物之一。氮氧化物是形成光化学烟雾的主要前驱物,控制和治理氮氧化物污染一直是国际环保领域的研究热点。在众多的脱硝方法中选择性催化还原法(SCR)的研究和应用最为广泛,以氨气为还原剂的SCR技术已在工业中广泛应用。 目前比较成熟的NH3-SCR催化剂是钒基催化剂,此催化剂具有较高的催化活性和抗硫性,工作温度是300～400℃,相应的脱硝装置位于除尘脱硫之前,烟气中高浓度的烟尘和SO2容易使催化剂堵塞或中毒,导致运行成本增加。开发低温催化剂(250℃以下)从而将脱硝装置放在除尘脱硫之后,有效避免上述问题,因而这项研究工作深受国内外同行的重视。锰基催化剂作为低温NH3-SCR催化剂的活性组分显现出优越的低温活性和N2选择性,而且价格低廉,制备工艺比较简单,有很广阔的应用前景。本文自行设计了固定床NOx选择性催化还原性能评价系统。研究发现,此两种催化剂都有非常好的低温选择性催化还原性能,在80℃时,NO转化率可达90%,N2选择性可达60%以上,在120℃时,NO转化率接近100%,这两种复合金属氧化物催化剂都是很优秀的NH3-SCR催化剂。

关键词：氮氧化物 锰基 选择性 低温

Abstract：With the continuous development of social economy, steel smelting, power generation, automobile exhaust and waste incineration will have a variety of ecological environment and human health hazards of gas, including nitrogen oxides (NOx) is more difficult to control and extremely harmful gaseouspollutants.The formation of nitrogen oxides are the main precursors of photochemical smog, nitrogen oxide pollution control, and governance has been the focus of international research in the field of environmental protection.Denitrification in many ways Selective Catalytic Reduction (SCR) of the study and most widely used ammonia as a reducing agent in SCR technology has been widely used in industry.The relatively mature NH3-SCR catalyst is vanadium-based catalysts, this catalyst has high catalytic activity and sulfur tolerance, operating temperature is 300 ~ 400 ℃, the corresponding device in the dust removal and desulfurization denitration prior to high concentrations of dust in flue gas and SO2 easily blocked or poisoning the catalyst, resulting in increased operational costs.Development of low-temperature catalyst (250 ℃ or less) to the denitrification unit on after the dust removal and desulfurization, which can effectively avoid the above problems,so this research attention by domestic and foreign counterparts.Manganese-based catalysts at low temperature NH3-SCR catalyst as the active component showing excellent low-temperature activity and N2 selectivity, and low cost, relatively simple preparation process, a very broad application prospects.Study found that the two catalysts have very good low temperature performance of selective catalytic reduction, at 80 ℃, NO conversion rate of 90%, N2 selectivity of up to 60% or more, at 120 ℃, NO conversion rate close to100%, both mixed metal oxide catalysts are very good NH3-SCR catalyst.

Key words:  Nitrogen oxides   Manganese  Selective  Low Temperature

本文正对锰基催化剂为主要的低温SCR催化剂活性组分开展研究，并对负载与非负载催化剂进行了对比。研究了催化剂的抗毒化性能，得到催化剂中毒的主要原因，并且通热态连续脱硝实验来研究催化剂的催化剂性能。为了能够使实验室催化剂向工业应用方向转变，本文还研究了两种成型方法对催化剂活性的影响。