發(fā)布時間：2018-06-26 20:31

  本文選題：煙氣脫硝 + 低溫等離子體�。� 參考：《大連理工大學(xué)》2015年碩士論文

【摘要】：氮氧化物(NOx)作為燃煤煙氣中主要的氣態(tài)污染物,對人類和生態(tài)環(huán)境造成嚴重的威脅。低溫等離子協(xié)同催化劑具有反應(yīng)速率高、不產(chǎn)生二次污染等特點,在污染物脫除領(lǐng)域受到廣泛關(guān)注。本研究針對工業(yè)煙氣低溫脫硝難度大、催化劑用量多等問題,提出利用低溫等離子體對NO預(yù)氧化與SCR協(xié)同快速脫硝,為NOx在低溫度窗口下脫硝探索一條新方法。本文研究了沿面放電氧活性物質(zhì)注入?yún)f(xié)同SCR和電暈放電協(xié)同SCR兩種煙氣脫硝方式。在沿面放電氧活性物質(zhì)注入中,清潔空氣通過沿面放電活化產(chǎn)生的氧活性物質(zhì)注入到煙氣中,將其中部分NO氧化；而在電暈放電中,煙氣則通過放電區(qū)域,NO的氧化反應(yīng)發(fā)生在低溫等離子體的發(fā)生區(qū)域。經(jīng)過低溫等離子體預(yù)氧化后,煙氣進入SCR反應(yīng)裝置完成脫硝反應(yīng)。本研究的主要工作及結(jié)果如下：(1)在低溫等離子體發(fā)生器優(yōu)化條件下,分別考察沿面放電氧活性物質(zhì)注入和電暈放電對含NOx的模擬煙氣的預(yù)處理效果。O3是沿面放電氧活性物質(zhì)注入氧化NO氧化的主要活性物質(zhì),而在電暈放電氧化的過程中,包括O·和OH·則都能參與到NO的氧化反應(yīng)中。(2)沿面放電氧活性物質(zhì)注入中,NO氧化效果隨著電壓的升高而升高,放電長度120mm,注入流量75mL/min,煙氣溫度150℃的實驗條件下,負載電壓2.7 kV時NO氧化效率為50%。(3)在電暈放電中,煙氣中含有一定量的H2O則對NO的氧化有顯著的促進作用,這歸因于H2O電離產(chǎn)生的OH·具有極高的氧化電位,對NO的氧化能力極強。(4)在150℃時,低溫等離子體協(xié)同SCR反應(yīng)的脫硝效率比單獨SCR提高了23%。低溫等離子體將煙氣中部分NO氧化形成N02,在催化劑表面形成NO3和NO2。一方面,NO2可以直接與NH3發(fā)生還原反應(yīng),另一方面,NO3對V4+-OH再氧化的加速作用進一步強化了低溫窗口下催化劑的脫硝能力。在高硫、高濕兩種煙氣的環(huán)境下,沿面放電協(xié)同SCR比標(biāo)準(zhǔn)SCR情況下的脫硝效率分別高出了31.9%和21.5%。而在電暈放電協(xié)同SCR中,H20的存在還會在電暈放電后引發(fā)低溫等離子體脫硝,脫硝效率比標(biāo)準(zhǔn)SCR效率高53%；當(dāng)向高濕的模擬煙氣中加入SO2時,脫硝效率則比單獨SCR情況下脫硝高出60%。
[Abstract]:Nitrogen oxides (NOx), as the main gaseous pollutants in coal-fired flue gas, pose a serious threat to human and ecological environment. Low temperature plasma synergistic catalyst has the characteristics of high reaction rate and no secondary pollution, so it has been paid more and more attention in the field of pollutant removal. In order to solve the problems such as the difficulty of denitrification at low temperature and the amount of catalyst used in industrial flue gas denitrification, a new method for NOx denitrification under low temperature window is proposed, in which no preoxidation and SCR can be rapidly denitrification by using low temperature plasma. Two ways of flue gas denitrification are studied in this paper: co-injection of oxygen active substances along surface discharge and co-discharge of corona discharge. In surface discharge oxygen active substance injection, clean air is injected into flue gas by surface discharge activation to oxidize part of no, while in corona discharge, The oxidation of no in flue gas occurs in the region of low temperature plasma. After low temperature plasma preoxidation, flue gas enters SCR reactor to complete denitrification. The main work and results of this study are as follows: (1) under the conditions of low temperature plasma generator optimization, The pretreatment effects of surface discharge oxygen active substance injection and corona discharge on NOx containing simulated flue gas were investigated respectively. O 3 is the main active substance for no oxidation by surface discharge oxygen active substance injection, but in the process of corona discharge oxidation, Both O and OH can participate in the oxidation of no. (2) the oxidation effect of no increases with the increase of voltage, the discharge length is 120mm, the injection flow rate is 75ml / min, and the flue gas temperature is 150 鈩，

本文編號：2071323