本文選題：NOx + 活性炭纖維�。� 參考：《河南科技大學(xué)》2015年碩士論文

【摘要】：氮氧化物是危害大氣的主要污染物之一,其排放已嚴重威脅著人類賴以生存的環(huán)境,并受到越來越廣泛的關(guān)注。選擇性催化還原(SCR)技術(shù)是脫除燃煤電廠排放煙氣中NOx的應(yīng)用最廣、有效技術(shù)之一。近年來低溫SCR技術(shù)由于具有節(jié)能減耗和運行成本低的特點正得到越來越多研究者的關(guān)注。從國內(nèi)外低溫SCR技術(shù)的研究現(xiàn)狀來看,該技術(shù)工業(yè)化的主要障礙是低溫范圍內(nèi)活性不高、催化劑抗毒化性能差、反應(yīng)機理不明確等問題。針對以上問題,本文使用以活性炭纖維為載體、Cu O和Zr O2作為主要活性成分的催化劑,對其低溫SCR脫硝性能進行了較為詳細的研究。本文選用濃硝酸處理的活性炭纖維為載體,以Cu O和Zr O2為活性組分,采用浸漬法制備出系列Cu O/ACFN、系列Zr O2/ACFN、系列Cu O-Zr O2/ACFN催化劑�？疾炝藵庀跛崽幚砘钚蕴坷w維、Cu O與Zr O2單獨作為活性組分、Cu O與Zr O2同時作為活性組分以及氧氣濃度、氨氮比等反應(yīng)條件對脫硝活性的影響,并通過比表面積(BET)與孔徑分析、X射線衍射(XRD)、掃描電鏡(SEM)、熱重差熱分析(TG-DTA)對催化劑進行分析和結(jié)構(gòu)表征,同時探討了氧含量、氨氮比等因素對系列催化劑的影響。研究結(jié)果表明活性炭纖維經(jīng)過濃硝酸處理后,比表面積增大了24.338m2/g,吸附量增大;負載Cu O與Zr O2后,催化劑的比表面積隨負載量的增加而降低,孔徑分析可知,Cu O與Zr O2的負載并未對活性炭的孔隙結(jié)構(gòu)造成明顯的影響,與XRD、SEM分析結(jié)果一致,Cu O、Zr O2負載量低于0.033Cu O/ACFN、0.025Zr O2/ACFN催化劑時,均為沒有明顯的Cu O、Zr O2特征峰的出現(xiàn),活性組分均勻的分布在活性炭纖維表面。結(jié)合脫硝活性實驗,系列Cu O-Zr O2/ACFN催化劑相比于系列Cu O/ACFN、系列Zr O2/ACFN催化劑在脫硝活性有較大的優(yōu)勢,3:1Cu O-Zr O2/ACFN催化劑在260℃達到最大92%的脫硝效率。氧氣能將NO氧化為NO2而促進脫硝反應(yīng)的進行,但氧氣濃度過小或過大時都不利于脫硝反應(yīng)的進行,經(jīng)測試氧氣濃度為3%時最佳;由脫硝反應(yīng)機理可知,NH3/NO=1:1,氨氮比過大會導(dǎo)致氧氣直接氧化NH3,從而降低脫硝效率,實驗結(jié)果顯示,NH3/NO=1時較為合理。通過本文的系統(tǒng)研究,開發(fā)了一種新型的Cu O-Zr O2/ACFN復(fù)合氧化物低溫SCR催化劑,與現(xiàn)有報道的SCR催化劑相比,該催化劑在低溫條件下的催化活性高、成本低等優(yōu)點,為低溫SCR工藝實現(xiàn)工業(yè)化應(yīng)用奠定了基礎(chǔ),為今后低溫SCR催化劑的進一步改進提供了指導(dǎo)。
[Abstract]:Nitrogen oxide is one of the main pollutants harmful to the atmosphere. Its emission has seriously threatened the environment on which human beings depend and has been paid more and more attention. Selective catalytic reduction (NOx) is one of the most widely used and effective technologies for removing NOx from flue gas from coal-fired power plants. In recent years, low temperature SCR technology has attracted more and more attention due to its characteristics of energy saving and low operation cost. According to the current research situation of low temperature SCR technology at home and abroad, the main obstacles to industrialization of this technology are low activity in low temperature range, poor antipoisoning performance of catalyst, unclear reaction mechanism and so on. In order to solve the above problems, the low temperature SCR denitrification performance of activated carbon fiber (ACF) supported by CuO and ZrO 2 catalysts was studied in detail. In this paper, a series of Cu O / A CFN, Zr O 2 / ACFN and Cu O-Zr O2/ACFN catalysts were prepared by impregnation method using concentrated nitric acid treated activated carbon fiber as carrier and CuO and ZrO 2 as active components. The effects of concentrated nitric acid treatment on denitrification activity of activated carbon fiber (ACF) treated with concentrated nitric acid, such as Cu O and ZrO 2 as active components, oxygen concentration, ammonia nitrogen ratio and so on, were investigated. The catalysts were characterized by specific surface area (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM) and thermogravimetric differential thermal analysis (TG-DTAA). The effects of oxygen content and the ratio of ammonia to nitrogen on the catalysts were also discussed. The results show that the specific surface area of activated carbon fiber increases by 24.338 m2 / g and the adsorption capacity increases after treatment with concentrated nitric acid, and the specific surface area of the catalyst decreases with the increase of loading amount of CuO and ZrO _ 2. The pore size analysis shows that the loading of CuO and ZrO 2 has no obvious effect on the pore structure of activated carbon. In accordance with the results of XRD SEM analysis, when the loading amount of Cu O 2 O 2 is lower than that of 0.033Cu O / A CFN O 0. 025 Zr O2/ACFN catalyst, there is no obvious characteristic peak of Cu O 2 O 2 O 2. The active components are uniformly distributed on the surface of the activated carbon fiber. Combined with the denitrification activity test, compared with the series Cu O / A CFN, the series of Cu O-Zr O2/ACFN catalysts have a better denitrification activity than the series Cu O / A CFN catalysts. The catalyst 3: 1 Cu O-Zr O2/ACFN has the highest denitrification efficiency of 92% at 260 鈩，

本文編號：1850991