本文關(guān)鍵詞： 濕法脫硝 過硫酸鉀 Fe(II)EDTA 氧化 活化　出處：《華中科技大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：煙氣中氮氧化物排放日趨嚴格,煙氣濕法脫硝技術(shù)開發(fā)研究具有重大意義,并成為國內(nèi)外研究熱點。氧化法被認為是實現(xiàn)中小鍋爐煙氣一氧化氮排放控制的有效方法之一,本文選用過硫酸鉀法對NO凈化進行了實驗研究。在分析了化學(xué)反應(yīng)原理、動力學(xué)、熱力學(xué)、氣液傳質(zhì)原理的基礎(chǔ)上,在鼓泡反應(yīng)器中進行了過硫酸鉀濕式去除模擬煙氣中NO的實驗,確定了各操作條件對脫除NO過程的影響。為提高NO去除率,通過實驗確定了合適的添加劑,并得到了最佳工藝條件,同時對其反應(yīng)機理進行了研究。得到了如下研究結(jié)果:(1)通過對過硫酸鹽的標準電極電位分析,發(fā)現(xiàn)過硫酸鹽能夠有效地氧化去除NO;(2)過硫酸鉀氧化NO的熱力學(xué)過程分析表明,過硫酸鉀氧化NO的反應(yīng)是自發(fā)行為;推導(dǎo)出反應(yīng)達到平衡狀態(tài)下NO分壓與反應(yīng)溫度的關(guān)系,但溫度升高不利于NO的氧化;氣液傳質(zhì)理論分析顯示,NO氣體的吸收主要由液膜控制。(3)在鼓泡反應(yīng)器內(nèi)進行了過硫酸鉀單獨脫除NO實驗,結(jié)果表明:過硫酸鉀濃度低于0.03mol/L時,NO去除率隨過硫酸鉀濃度增大而增大,過硫酸鉀濃度大于0.03mol/L時,NO去除率基本保持不變;NO去除率隨反應(yīng)溫度變化曲線呈倒U型曲線,在60℃時達到最大去除率;堿性條件下NO去除率高于酸性條件下,在pH為13.0時達到最大去除率。(4)Fe(II)EDTA是合適的添加劑,當過硫酸鉀濃度為0.02mol/L,Fe(II)EDTA濃度為0.03mol/L,反應(yīng)溫度80℃,初始pH為9.0時,NO去除率可達93%。(5)Fe(II)EDTA聯(lián)合過硫酸鉀溶液去除煙氣中NO的機理研究顯示,Fe(II)EDTA不僅可有效活化過硫酸根產(chǎn)生強氧化性的硫酸根自由基?SO4-,同時與NO形成絡(luò)合物。
[Abstract]:The emission of nitrogen oxides from flue gas is becoming more and more strict, so it is of great significance to develop and study the technology of flue gas wet denitrification. Oxidation method is considered to be one of the effective methods to control the emission of nitric oxide in flue gas of medium and small boilers. In this paper, the purification of no by potassium persulfate method is studied experimentally. The chemical reaction principle, kinetics, thermodynamics and gas-liquid mass transfer principle are analyzed. The experiment of wet removal of no from simulated flue gas by potassium persulfate in bubbling reactor was carried out, and the effect of operation conditions on the process of no removal was determined in order to improve the removal rate of no. The suitable additives were determined by experiments and the optimum process conditions were obtained. The reaction mechanism was also studied. The following results were obtained: 1) the standard electrode potential analysis of persulfate was carried out. It is found that persulfate can effectively oxidize and remove no. 2) the thermodynamic process analysis of the oxidation of no by potassium persulfate shows that the oxidation of no by potassium persulfate is spontaneous; The relationship between the partial pressure of no and the reaction temperature is deduced when the reaction reaches equilibrium, but the increase of temperature is not conducive to the oxidation of no. The theoretical analysis of gas-liquid mass transfer shows that the absorption of no gas is mainly controlled by liquid membrane. The results showed that when the concentration of potassium persulfate was lower than 0.03mol / L, the removal rate of no increased with the increase of potassium persulfate concentration, and when the concentration of potassium persulfate was greater than 0.03mol / L. The removal rate of no remained basically unchanged; The curve of no removal rate varies with reaction temperature, and reaches the maximum removal rate at 60 鈩，

本文編號：1484381