Effect Mechanism of O2 and H2O on SO2 Conversion and Existence Form in Activated Coke
Effect Mechanism of O2 and H2O on SO2 Conversion and Existence Form in Activated Coke
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DOI：
10.1109/cdciem.2011.207
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发表时间：
2011-02
期刊：
影响因子：
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通讯作者：
Sun Fei;Gao Jihui;Zhu Yuwen;Qin Yukun
中科院分区：
文献类型：
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作者：
Sun Fei;Gao Jihui;Zhu Yuwen;Qin Yukun
活性焦法烟气脱硫技术(FGD)具有节水、污染物可回收利用等优点，被认为是FGD的重要发展方向。本文采用固定床法和离子色谱法研究了模拟烟气中O2和H2O对活性焦中SO2转化率和存在形态的影响机理。研究结果表明：氧气使一些化学吸附的SO2氧化成SO3，SO3的吸附方式与SO2的吸附方式不同。SO3的形成使SO2吸附活性中心空置，为进一步吸附SO2创造了条件。SO3能与H2O(G)反应生成H2SO4(G)。硫酸蒸汽的冷凝促进了SO3和H2O(G)的反应，进而促进了SO2的氧化。O2浓度的增加会降低扩散阻力，增加氧气向活性中心扩散的可能性，烟气中过量的H2O(G)形成过量的水膜，堵塞气孔，淹没活性中心，最终阻碍SO2和O2向微孔的扩散。O2和H2O是交流脱硫过程中必不可少的物质。SO3和H2O(G)的反应和硫酸蒸汽的冷凝是AC脱硫过程的动力学过程。化学吸附的SO2和O2的氧化反应是整个过程的速率控制步骤。
Activated coke flue gas desulfurization technology(FGD) which has the advantages of water-saving and pollutant recyclable utilization is considered the important development direction of FGD. In this paper, effect mechanism of O2 andH2O in simulated flue gas on SO2 conversion and existence form in activated coke is studied through the methods of fixed bed and ion chromatography. The research results show that:O2 makes some chemical adsorbed SO2 be oxidized to SO3whose adsorption pattern is different from that of SO2. The formation of SO3 makes SO2 adsorption active sites vacant and creates the conditions to further adsorb SO2. SO3 can react with H2O (g) to H2SO4 (g). The condensation of sulfuric acid vapor promotes the reaction of SO3 and H2O (g), and further promotes the oxidation of SO2. Increase of O2 concentration can reduce the diffusion resistance and increase the probability of oxygen diffusion to the active sites, Excess H2O (g) in flue gas forms excess water film which can plug the pores and flood active sites, and ultimately hinder the diffusion of SO2 and O2to micro pores. O2 and H2O are necessary in AC desulfurization process. Reaction of SO3 and H2O (g) and condensation of sulfuric acid vapor are the dynamic of AC desulfurization process. Oxidation reaction of chemical adsorbed SO2 and O2is the rate controlling step of the whole process.