过硫酸钾湿法氧化净化一氧化氮实验研究

发布时间：2018-02-02 11:15

  本文关键词： 湿法脱硝 过硫酸钾 Fe(II)EDTA 氧化 活化　出处：《华中科技大学》2015年硕士论文　论文类型：学位论文

【摘要】：烟气中氮氧化物排放日趋严格,烟气湿法脱硝技术开发研究具有重大意义,并成为国内外研究热点。氧化法被认为是实现中小锅炉烟气一氧化氮排放控制的有效方法之一,本文选用过硫酸钾法对NO净化进行了实验研究。在分析了化学反应原理、动力学、热力学、气液传质原理的基础上,在鼓泡反应器中进行了过硫酸钾湿式去除模拟烟气中NO的实验,确定了各操作条件对脱除NO过程的影响。为提高NO去除率,通过实验确定了合适的添加剂,并得到了最佳工艺条件,同时对其反应机理进行了研究。得到了如下研究结果:(1)通过对过硫酸盐的标准电极电位分析,发现过硫酸盐能够有效地氧化去除NO;(2)过硫酸钾氧化NO的热力学过程分析表明,过硫酸钾氧化NO的反应是自发行为;推导出反应达到平衡状态下NO分压与反应温度的关系,但温度升高不利于NO的氧化;气液传质理论分析显示,NO气体的吸收主要由液膜控制。(3)在鼓泡反应器内进行了过硫酸钾单独脱除NO实验,结果表明:过硫酸钾浓度低于0.03mol/L时,NO去除率随过硫酸钾浓度增大而增大,过硫酸钾浓度大于0.03mol/L时,NO去除率基本保持不变;NO去除率随反应温度变化曲线呈倒U型曲线,在60℃时达到最大去除率;碱性条件下NO去除率高于酸性条件下,在pH为13.0时达到最大去除率。(4)Fe(II)EDTA是合适的添加剂,当过硫酸钾浓度为0.02mol/L,Fe(II)EDTA浓度为0.03mol/L,反应温度80℃,初始pH为9.0时,NO去除率可达93%。(5)Fe(II)EDTA联合过硫酸钾溶液去除烟气中NO的机理研究显示,Fe(II)EDTA不仅可有效活化过硫酸根产生强氧化性的硫酸根自由基?SO4-,同时与NO形成络合物。
[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，

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