發(fā)布時(shí)間：2018-03-14 20:46

  本文選題：燃煤煙氣　切入點(diǎn)：脫砷　出處：《華北電力大學(xué)》2017年碩士論文　論文類(lèi)型：學(xué)位論文

【摘要】：我國(guó)的大氣污染屬于典型的煤煙型污染,煤炭燃燒過(guò)程產(chǎn)生的SO_2、NOx、顆粒物、痕量重金屬、VOCs等污染物,對(duì)生態(tài)環(huán)境和人類(lèi)健康造成了嚴(yán)重危害。砷是煤中最易揮發(fā)的有害微量元素之一,被國(guó)際癌癥研究機(jī)構(gòu)列為第一類(lèi)致癌物,應(yīng)格外引起人們的關(guān)注。目前對(duì)于燃煤電廠砷污染控制的研究相對(duì)較少,因此開(kāi)發(fā)一種投資費(fèi)用少、運(yùn)行成本低、綠色環(huán)保的煙氣脫砷工藝對(duì)燃煤電廠砷的減排以及最終實(shí)現(xiàn)多種污染物聯(lián)合脫除有著極為重要的意義。本文在閱讀大量文獻(xiàn)的基礎(chǔ)上設(shè)計(jì)了脫砷實(shí)驗(yàn)方案,搭建脫砷室驗(yàn)臺(tái)。通過(guò)篩選多種氧化劑,最終選取了H_2O_2為基礎(chǔ)氧化劑,Na_2S_2O_8為添加劑制作復(fù)合氧化劑。采用自行設(shè)計(jì)的脫砷實(shí)驗(yàn)臺(tái)考察了復(fù)合氧化劑的濃度配比和反應(yīng)條件等因素對(duì)脫砷效率的影響,確定了H_2O_2/Na_2S_2O_8復(fù)合氧化劑的最佳反應(yīng)條件:Na_2S_2O_8與H_2O_2的最佳摩爾濃度比為0.01/1(mol/mol),反應(yīng)溫度為50℃,復(fù)合氧化劑p H值為5.5,煙氣流量為1.0L/min、入口處砷濃度為0.421mg/m~3。在最佳反應(yīng)條件下獲得的平均脫砷效率96.3%。為了模擬燃煤電廠煙氣的實(shí)際工況,分別考察了O_2、CO_2、SO_2、NO濃度對(duì)脫砷效率的影響,實(shí)驗(yàn)結(jié)果表明:隨著O_2和CO_2濃度的增加,脫砷效率幾乎不受影響;隨著SO_2濃度增大,脫砷效率呈下降趨勢(shì);隨著NO濃度增大,脫砷效率先下降后緩慢上升。通過(guò)對(duì)脫砷產(chǎn)物進(jìn)行AFS、液相色譜和XRD檢測(cè),證實(shí)了脫砷產(chǎn)物為Ca_3(As O_4)_2。根據(jù)產(chǎn)物表征結(jié)果和相關(guān)文獻(xiàn),推測(cè)了H_2O_2/Na_2S_2O_8復(fù)合氧化劑的脫砷機(jī)理。
[Abstract]:The air pollution in our country belongs to the typical coal smoke pollution, so _ 2no _ x, particulates, trace heavy metals such as VOCs produced by the coal combustion process, etc. Arsenic is one of the most volatile harmful trace elements in coal. There is relatively little research on arsenic pollution control in coal-fired power plants, so the development of a kind of arsenic pollution has low investment cost and low operating cost. The process of removing arsenic from flue gas by green environment is of great significance to the reduction of arsenic in coal-fired power plants and the realization of combined removal of various pollutants. Based on the reading of a large number of literatures, the experimental scheme of arsenic removal is designed in this paper. Setting up a laboratory test bench for arsenic removal. By screening various oxidants, Finally, H _ 2O _ 2 was selected as the basic oxidant to make composite oxidant. The influence of the concentration ratio and reaction conditions of the compound oxidant on the efficiency of arsenic removal was investigated by using the self-designed experimental bench. The optimum reaction conditions for the composite oxidant, the one of the H2O2S _ 2O _ 8, were determined: the optimum molar concentration ratio of the two was 0.01 / 1 mol / mol / h, and the reaction temperature was 50 鈩，

本文編號(hào)：1612822