低床层烟炱和石灰粉混合物吸附法烟气脱硫实验研究

【作者】 张小广；

【导师】 陈凡植；

【作者基本信息】 广东工业大学 ， 环境工程， 2003， 硕士

【摘要】 干法烟气脱硫技术具有工艺简单，操作简便，投资、运行和维护费用低廉，脱硫产物易于处理等特点而引起人们的广泛关注。目前，我国的二氧化硫污染现象十分普遍，酸雨污染形势亦非常严峻，控制和治理SO₂污染已经刻不容缓。然而烟气脱硫技术因其投资较高，运行管理费用庞大等原因，难以适应发展中国家的国情，制约了该技术的推广应用。本文即是着眼于我国SO₂污染的现状，针对低浓度二氧化硫废气的治理，采用燃油锅炉排出的废弃物——烟炱掺加石灰粉的混合物为吸附剂，以废治废，开发一种经济、高效的干法烟气脱硫技术。 本实验采用燃油锅炉排出的烟炱掺加石灰粉作为混合吸附剂，研究在低床层条件下吸附剂对SO₂的脱除效果。先在测定烟炱和石灰粉混合吸附剂基本性质的基础上，通过实验考察了影响脱硫效果的主要因素及其影响规律。并对吸附剂的脱硫机理进行了探讨。 本文研究了进气SO₂浓度、进气风速、烟气温度、烟炱和石灰粉配比等因素对吸附剂脱硫效率的影响，同时考察了出口烟气SO₂浓度随时间的变化关系；并研究了经氧化铁、氧化铜和氧化铝改性对吸附剂脱硫效率的影响。结果表明，在本研究条件下脱硫效率随烟气温度的升高而降低，低温有利于SO₂的去除；在实验范围内随烟气流速的减小而增加，进气二氧化硫浓度与脱硫效率的关系具有极值，该法对于SO₂浓度为2300mg／m³的烟气有较好的处理效果。烟炱和石灰粉的配比对脱硫效率有一定的影响，实验表明烟炱和石灰粉配比为3：1时脱硫效果较好；在吸附剂中加入金属氧化物能够显著提高脱硫效率，而且在较高效率下能够维持较长的时间，金属氧化物在烟炱表面的分散程度能明显影响脱硫效率的提高，采用中间体受热分解对吸附剂改性的方法，明显优于直接物理混合分散。 通过对SO₂在烟炱上的吸附等温线的研究数据表明，可以用Freundlich方程来描述，用表面选择性吸附机理能够解释SO₂在烟炱上的吸附。而且透射电镜照片也直观地显示出了烟炱表面的一层吸附膜。通过吸附剂的FDP曲线的研究显示，H₂SO₄从吸附剂表面的脱附是整个吸附反应的控制步骤，对SO₂的脱除具有重要影响。更多还原

【Abstract】 The dry flue gas desulphunzation technique has bring extensive because its simple technique and manipulation-, low investment operation and maintance fee and easy disposal of the desulphunzation product. Now sulfur dioxide and acid rian pollution has become a commen and critical phenomenon in China, so it’s no time to delay to control and treat SCh pollution. But because of its high investment operation fee et al, flue gas desulphunzation techniques is not suitable for the development country to take. In this article study a economical and effective dry flue gas desulphunzation techniques is described aimed at the SOa pollution of our country and the low concentration of SQz desulphurization in flue gas.This paper systematically studies the influence of the process conditions, such as SO2 concentration in flue gas, flue gas temperature and gas velocity of flow etc,on the efficiency of the sorbent ,the change of outlet concentration of SCh and the influence of the sorbent treated by Fe^O^ CuO and A12C>3. The result of experiments shows: the desulphurization efficiency decrease with flue gas temperature increasing, so low temperature is more suitable for desulphurization under the experimental condition we chosed; in the experimental, the desulphurization efficiency increase with velocity of flue gas decreasing and there is a extremum between SOj concentration in flue gas and the desulphurization efficiency. This method is more effective for the treatment of SOa concentration of 2300mg/m3 in flue gas. The ratio of soot and calcareousness powder also influent the desulphurization efficiency. It can be seen the best ratio is 3:1; The desulphurization efficiency can be notably increased and maintain at high level when metal oxide is added into sorbent The disperse degree of metal oxide can influent the increase of the desulphurization efficiency and it can be seen that the method of disperse by means of decompound of the middle product be heated is better than that of by mixing by hand.By studying adsorption isotherms of adsorbent of the SO2 absorption, we could describe the desulphurization mechanism of adsorption by Freundlich equaption andiiAbstractinterpreted the absorption by surface selected adsorption. It can be seen directly that there is a layer of adsorption film on the soot surface in TEM. The FDP line of adsorbent show that HfeSCU desorption from the soot surface is the key step of the whole absorption reaction and is the important influence factor on desulphurization.更多还原