燃煤烟气中单质汞氧化和吸附脱除研究

论文总字数：27638字

摘 要

一、进行了UV/H2O2高级氧化工艺氧化脱汞的试验研究，研究了紫外灯功率、H2O2初始浓度、Hg0初始浓度和溶液体积对Hg0去除效率的影响，研究内容和结论概括如下：

（1）UV/H2O2高级氧化工艺作为一种新型技术，可以有效去除烟气中的部分Hg0；

（2）研究了三种紫外灯功率（0W、15W和25W）下的Hg0去除效率，研究发现：紫外灯的引入可以显著提高Hg0去除效率，并且25W紫外灯较之15W紫外灯对Hg0的去除效果要好；

（3）研究了不同H2O2初始浓度下的Hg0去除效率，研究发现：当H2O2初始浓度较低时，Hg0去除效率随着H2O2初始浓度的增加而上升；但是当H2O2初始浓度增加到一定程度后，Hg0去除效率的上升幅度显著降低直至Hg0去除效率出现下降的趋势；

（4）通过调节恒温水浴5的温度研究了不同Hg0初始浓度下的Hg0去除效率，研究发现：Hg0去除效率随着Hg0初始浓度的增加而下降；

（5）研究了不同溶液体积下的Hg0去除效率，研究发现：Hg0去除效率随着溶液体积的增加而上升。

二、进行了UV/TiO₂光催化氧化脱汞的实验研究，考察了活性组分含量、反应温度、Hg0初始浓度、含氧量、停留时间、含湿量对Hg0去除效率的影响，研究结论概括如下：

（1）光催化氧化工艺可以有效去除烟气中的部分Hg0；

（2）仅有紫外灯照射时，也能使少量Hg0转化；

（3）活性组分含量对光催化脱汞效率的影响：光催化剂的脱汞效率随着活性组分含量的增加而上升，但上升速率逐渐下降；

（4） 温度对光催化脱汞效率的影响：温度的改变并未引起光催化脱汞效率的明显变化；

（5）Hg0初始浓度对光催化脱汞效率的影响：光催化脱汞效率随着Hg0初始浓度的升高而下降；

（6）烟气含氧量对光催化脱汞效率的影响：光催化脱汞效率首先随着含氧量的升高而上升，当含氧量为6%时，光催化剂的脱汞效率达到最大(39.2%)；当含氧量大于8%时，光催化剂的脱汞效率基本不变；

三、在新型脱汞吸附剂的开发研究中，对凹凸棒土及其改性吸附剂、废轮胎热解焦及其改性吸附剂在不同温度下进行Hg⁰穿透特性测试，结果为：

（1）凹凸棒土及其改性吸附剂、废轮胎热解焦及其改性吸附剂均可以有效吸附去除烟气中的部分Hg0；

（2）FeCl3改性凹凸棒土、CuCl2改性凹凸棒土和S改性凹凸棒土的吸附脱汞性能较原始吸附剂有较好的增强；

（3）550℃温度下热解得到的废轮胎热解焦吸附脱汞性能最佳；

（4）HCl、NH₄Cl、NaCl、FeCl₃、Cu(NO3)₂、Fe(NO₃)₃、Mn(NO₃)₂、Zr(NO₃)4、Ce(NO3)3和K2Cr2O7改性的废轮胎热解焦(550℃)吸附脱汞性能显著增强，尤其是HCl和NaCl，其价格便宜，来源广泛，有很好的工业应用价值。

关键词：氧化脱汞；UV/H₂O₂高级氧化；UV/TiO₂光催化氧化；新型脱汞吸附剂

Study on oxidation and adsorption removal of elemental mercury in coal fired flue gas

03213714 Yelei Zhang

Supervised by Zhang Bo

Abstract：

1.The researcher carries out the mercury removal experiment by UV/H2O2 advanced oxidation technology. The researcher studies the effects of UV lamp power, H2O2 initial concentration, Hg0 initial concentration and solution volume on the removal efficiency of Hg0, the research contents and conclusions are summarized as follows:

(1) As a new technology, UV/H2O2 advanced oxidation process can effectively remove part of Hg0 in flue gas;

(2) The researcher studied the removal efficiency of Hg⁰ of three kinds of UV lamp power (0W, 15W and 25W), the study found that the use of UV lamp can significantly improve the removal efficiency of Hg⁰.And the removal efficiency of Hg⁰ of 25W UV lamp power is better compared with the removal efficiency of Hg⁰ of 15W UV lamp power;

3) The researcher studied the removal efficiency of Hg⁰ at different initial concentration of H2O2. The study found that: when the initial concentration of H2O2 is low, the removal efficiency of Hg⁰ increased with the increase of the concentration of H2O2; but when the initial concentration of H2O2 increased to a certain extent, the rising range of Hg0 removal efficiency decreased significantly until the removal efficiency of Hg⁰ begin to decrease;

(4) The researcher studied the removal efficiency of Hg⁰ at different initial concentrations of Hg⁰ by adjusting the temperature of the constant temperature water bath 5. The results showed that the removal efficiency of Hg⁰ decreased with the increase of initial concentration of Hg⁰;

(5) The researcher studied the removal efficiency of Hg0 in different solution volumes. The results showed that the removal efficiency of Hg⁰ increased with the increase of the volume of the solution.

2.The researcher carried out an experimental study on UV/TiO2 photocatalytic oxidation of mercury removal and investigated the effects of active component content, reaction temperature, initial concentration of Hg0, oxygen content, residence time and moisture content on removal efficiency of Hg0. The conclusions are summarized as follows:

(1) Photocatalytic oxidation process can effectively remove part of Hg0 in flue gas;

(2) A small amount of Hg0 can be converted when only irradiated by an ultraviolet lamp;

(3) The effect of the active component content on the photo catalyst removal efficiency of mercury: the mercury removal efficiency of the photo catalyzer increases with the increase of the active component content, but the rate of increase decreases gradually;

(4) The influence of temperature on the efficiency of photocatalytic removal of mercury: the change of temperature did not lead to the obvious change of the efficiency of photocatalytic removal of mercury;

(5) The influence of Hg⁰ initial concentration on photocatalytic removal efficiency of mercury: the photocatalytic removal efficiency decreased with the increase of Hg0 initial concentration;

(6) The influence of oxygen content of flue gas on photocatalytic removal efficiency of mercury:

First, the photocatalytic mercury removal efficiency increases with the increase of oxygen, when the oxygen content is 6%, the photo catalyst mercury removal efficiency reached the maximum (39.2%); when the oxygen content is greater than 8%, the mercury removal efficiency of photo catalyst is basically unchanged;

三、In the research and development of new mercury removal sorbent, the researcher tested the Hg⁰ penetration characteristics of attapulgite and its modified adsorbent, waste tire pyrolysis coke and its modified adsorbent at different temperatures. The conclusions are summarized as follows:

(1) Attapulgite and its modified adsorbent, waste tire pyrolysis coke and its modified adsorbent can effectively adsorb and remove part of Hg0 in flue gas;

(2) The adsorption and removal of mercury of FeCl3 modified attapulgite, CuCl2 modified attapulgite and S modified attapulgite are better than those of the original adsorbent;

(3) The pyrolysis and desorption of waste tire pyrolysis coke obtained at 550 C temperature is the best;

(4) The mercury removal and adsorption performance of HCl、NH4Cl、NaCl、FeCl3、Cu(NO3)2、Fe(NO3)3、Mn(NO3)2、Zr(NO3)4、Ce(NO3)3 and K2Cr2O7 modified waste tires pyrolysis cokes are significantly enhanced. Especially HCl and NaCl modified waste tires pyrolysis cokes, their prices are cheap, sources are wide, and have very good industrial application value.

Key words: Oxidative mercury removal; UV/H2O2 advanced oxidation; UV/TiO2 photocatalytic oxidation; New mercury removal sorbent

目 录

1、 绪论 1

2、 UV/H2O2高级氧化工艺脱汞的试验研究 3

2.1引言 3

2.2、试验 4

2.2.1 试验装置 4

2.2.2 化学试剂 6

2.2.3 试验步骤 6

2.2.4数据处理 6

2.3试验结果与讨论 7

2.3.1 紫外灯功率对Hg⁰去除效率的影响 7

2.3. 2 H₂O₂初始浓度对Hg⁰去除效率的影响 7

2.3. 3Hg0初始浓度对Hg0去除效率的影响 9

2.3. 4溶液体积对Hg0去除效率的影响 10

2.4总结 11

3、UV/TiO2光催化氧化工艺脱汞的试验研究 12

3.1、引言 12

3.2、试验 14

3.2.1 光催化剂的制备 14

3.2.2 光催化氧化小试实验台 14

3.3、试验结果与讨论 15

3.3.1 空白试验（有紫外灯、无光催化剂） 15

3.3.2 活性组分含量对光催化脱汞效率的影响 16

3.3.3 温度对光催化脱硝效率的影响 17

3.3.4 Hg0初始浓度对光催化脱硝汞效率的影响 18

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