摘要：隨著社會(huì)經(jīng)濟(jì)的不斷發(fā)展,鋼鐵冶煉、火力發(fā)電、汽車尾氣及垃圾焚燒等都會(huì)產(chǎn)生各種危害生態(tài)環(huán)境和人類健康的氣體,其中氮氧化物(NOx)是較難治理又危害極大的氣態(tài)污染物之一。氮氧化物是形成光化學(xué)煙霧的主要前驅(qū)物,控制和治理氮氧化物污染一直是國(guó)際環(huán)保領(lǐng)域的研究熱點(diǎn)。在眾多的脫硝方法中選擇性催化還原法(SCR)的研究和應(yīng)用最為廣泛,以氨氣為還原劑的SCR技術(shù)已在工業(yè)中廣泛應(yīng)用。 目前比較成熟的NH3-SCR催化劑是釩基催化劑,此催化劑具有較高的催化活性和抗硫性,工作溫度是300～400℃,相應(yīng)的脫硝裝置位于除塵脫硫之前,煙氣中高濃度的煙塵和SO2容易使催化劑堵塞或中毒,導(dǎo)致運(yùn)行成本增加。開發(fā)低溫催化劑(250℃以下)從而將脫硝裝置放在除塵脫硫之后,有效避免上述問題,因而這項(xiàng)研究工作深受國(guó)內(nèi)外同行的重視。錳基催化劑作為低溫NH3-SCR催化劑的活性組分顯現(xiàn)出優(yōu)越的低溫活性和N2選擇性,而且價(jià)格低廉,制備工藝比較簡(jiǎn)單,有很廣闊的應(yīng)用前景。本文自行設(shè)計(jì)了固定床NOx選擇性催化還原性能評(píng)價(jià)系統(tǒng)。研究發(fā)現(xiàn),此兩種催化劑都有非常好的低溫選擇性催化還原性能,在80℃時(shí),NO轉(zhuǎn)化率可達(dá)90%,N2選擇性可達(dá)60%以上,在120℃時(shí),NO轉(zhuǎn)化率接近100%,這兩種復(fù)合金屬氧化物催化劑都是很優(yōu)秀的NH3-SCR催化劑。

關(guān)鍵詞：氮氧化物 錳基 選擇性 低溫

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

本文正對(duì)錳基催化劑為主要的低溫SCR催化劑活性組分開展研究，并對(duì)負(fù)載與非負(fù)載催化劑進(jìn)行了對(duì)比。研究了催化劑的抗毒化性能，得到催化劑中毒的主要原因，并且通熱態(tài)連續(xù)脫硝實(shí)驗(yàn)來(lái)研究催化劑的催化劑性能。為了能夠使實(shí)驗(yàn)室催化劑向工業(yè)應(yīng)用方向轉(zhuǎn)變，本文還研究了兩種成型方法對(duì)催化劑活性的影響。