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【目的】元素汞(Hg0)和氧化态汞(Hg2+)的选择性吸附是汞连续在线监测系统中的关键技术之一。氧化镁(MgO)是常见的吸附剂，但由于其表面积较小、使用寿命短、烟气组分影响机制不明确，其应用受到一定限制。为解决吸附剂在应用中的限制，提升Hg0的脱除效率，有必要对MgO基吸附剂进行深入研究。【方法】本研究采用溶胶凝胶法，将MgO负载至孔隙发达的γ-Al_2O3表面，以提升其对HgCl2的吸附性能，并通过实验和多种表征方法阐明烟气组分与HgCl2在镁基吸附剂表面的竞争反应机制。【结果】研究表明，最佳前驱体为草酸镁，且MgO与载体的摩尔比为1.5∶1.0时，达到最优负载比例。相对于原始Mg O，负载后吸附剂的比表面积从14.54 m2/g上升为143.15 m2/g，对HgCl2穿透率从36.20%降低至2.78%。分别单独加入500µL/L NO、12%O2后，HgCl2的对应穿透率分别为4.20%、2.77%，这些非酸性气体不会干扰吸附剂对Hg0和HgCl2的选择性吸附性能。然而，分别单独加入50µL/L HCl、200µL/L SO2、16%CO2后，HgCl2的对应穿透率分别降至13.50%、26.07%、6.56%。这是由于酸性气体与HgCl2在吸附剂表面发生竞争吸附，消耗碱性活性位点，同时堵塞吸附剂孔隙，抑制吸附剂对HgCl2的捕集。【结论】这些实验结果对MgO基选择性吸附剂的工业应用提供了理论指导。
Abstract：[Objective] Selective adsorption of elemental mercury(Hg0) and oxidized mercury(Hg2+) is one of the key technologies in continuous mercury emission monitoring systems(Hg-CEMS). Magnesium oxide(MgO) is a commonly used adsorbent; however, its application is limited due to its relatively low surface area, short service life, and unclear interaction mechanisms with flue gas components. In order to solve the limitations of adsorbents in application and improve the removal efficiency of Hg0, it is necessary to conduct in-depth research on MgO-based adsorbents.[Methods] In this study, MgO was supported on porous γ-Al_2O3 via a sol-gel method to enhance its adsorption performance for HgCl2. Experimental investigations and various characterization techniques were employed to elucidate the competitive reaction mechanisms between flue gas components and HgCl2 on the surface of Mg-based adsorbents. [Results] The results show that the best precursor is magnesium oxalate, and the optimal loading ratio is achieved when the molar ratio of MgO to carrier is 1.5∶1.0. Compared with the original MgO, the specific surface area of the loaded adsorbent increased from 14.54 m2/g to 143.15 m2/g, and the penetration rate of HgCl2 decreased from 36.2% to 2.78%. After adding 500 μL/L NO and 12% O2 separately, the corresponding penetration rates of HgCl2 were 4.20% and 2.77%, respectively.These non-acid gases will not interfere with the selective adsorption performance of the adsorbent for Hg0 and HgCl2. However, when 50 μL/L HCl, 200 μL/L SO2 and 16% CO2 were added separately, the corresponding penetration rates of HgCl2 decreased to 13.50%, 26.07% and 6.56%, respectively. This is due to the competitive adsorption of acidic gases and HgCl2 on the surface of the adsorbent, which consumes alkaline active sites, blocks the pores of the adsorbent, and inhibits the capture of HgCl2 by the adsorbent. [Conclusion] These findings provide theoretical guidance for the industrial application of MgO-based selective adsorbents.
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基本信息:
DOI：10.19944/j.eptep.1674-8069.2026.03.001
中图分类号:TQ424;X773
引用信息:
[1]尚瑜,李海洋,陈盈盈,等.氧化镁基吸附剂选择性分离Hg~0和HgCl_2的特性研究[J].电力科技与环保,2026,42(03):345-356.DOI:10.19944/j.eptep.1674-8069.2026.03.001.
基金信息:
国家重点研发计划项目（2016YFC0201105）; 江苏省生态环境厅环保科研课题项目（2016030）
2026-06-15
2026-06-15