Simultaneous removal of SO₂, NO and Hg⁰ through an integrative process utilizing a cost-effective complex oxidant.
Simultaneous removal of SO₂, NO and Hg⁰ through an integrative process utilizing a cost-effective complex oxidant.
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DOI：
10.1016/j.jhazmat.2015.08.049
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发表时间：
2016-01
影响因子：
13.6
通讯作者：
Yi Zhao;Runlong Hao;Bo Yuan;Jiajun Jiang
中科院分区：
文献类型：
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作者：
Yi Zhao;Runlong Hao;Bo Yuan;Jiajun Jiang
提出了一种预氧化后吸收同时脱除烟气中SO2、NO和Hg0的新工艺。制备了一种经济实惠的H_2O_2和NaClO_2组成的蒸发复合氧化剂(CO)来氧化Hg0和NO，然后用Ca(OH)_2溶液吸附氧化产物。为确定最佳反应条件，考察了CO中H_2O_2与NaClO_2的摩尔比、CO的加入量、CO的pH值、反应温度、烟气停留时间和共存气体等因素对同时脱除SO2、NO和HgO的影响。实验结果表明，在所有实验条件下，脱硫率基本不变，而NO和Hg0的脱除主要受NaClO2加入量、CO加入量、CO的pH值、反应温度等因素的影响。同时，NO和SO2是Hg0脱除的促进剂。在最佳反应条件下，SO2、NO和Hg0的最佳同时脱除效率分别为100%、87%和92%。根据UV-Vis、EDX、XRD、AFS和XPS对脱除产物的表征，推测了反应机理。
A novel process of pre-oxidation combining with post-absorption to simultaneously remove SO2, NO and Hg0from flue gas was proposed. A vaporized complex oxidant (CO) consisted of cost-effective H2O2and NaClO2was prepared to oxidize Hg0and NO, then the oxidation products were absorbed by the Ca(OH)2solution that was followed. For the establishment of the optimal reaction conditions, the influences of various reaction factors on the simultaneous removal of SO2, NO and Hg0were investigated, i.e., the molar ratio of H2O2to NaClO2in CO, the adding rate of CO, the pH of CO, the reaction temperature, the flue gas residence time and the coexistence gases. The experimental results indicated that the desulfurization was constant in all tests, whereas the removal of NO and Hg0was primarily affected by the NaClO2addition, the adding rate of CO, the pH of CO, and the reaction temperature. Meanwhile, NO and SO2were characterized as the promoters for the Hg0removal. Under the optimal reaction conditions, the best simultaneous removal efficiencies were 100% for SO2, 87% for NO and 92% for Hg0. According to the characterizations of removal products by UV–vis, EDX, XRD, AFS and XPS, the reaction mechanism was speculated.