Mercury Removal from Flue Gases by Novel Regenerable Magnetic Nanocomposite Sorbents
Mercury Removal from Flue Gases by Novel Regenerable Magnetic Nanocomposite Sorbents
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DOI：
10.1021/es803306n
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发表时间：
2009-05-01
影响因子：
11.4
通讯作者：
Kuznicki, Steven M.
中科院分区：
文献类型：
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作者：
Dong, Jie;Xu, Zhenghe;Kuznicki, Steven M.
磁性分子筛负载银纳米粒子复合材料是一类新型的多功能材料，在可回收催化剂、消毒剂和吸附剂等方面具有潜在的应用前景。本研究评估了磁性复合材料作为吸附剂去除燃煤电厂烟气中元素汞蒸气的适用性。吸附剂被发现完全捕获汞在温度高达200摄氏度，和吸附剂的汞容量被发现受复合材料中的状态，含量和银颗粒的大小。在400摄氏度下进行累积或延长的热处理可以提高汞捕获能力，使吸附剂可以多次再生和再循环，而不会降低性能。磁性吸附剂通过磁性分离容易地从飞灰中分离，使得飞灰基本上没有吸附剂污染。在最初的厂内测试中，吸附剂能够从一个运行中的全规模燃煤发电厂的烟道气中捕获汞。汞容量、易于分离和再生以及可回收性的组合使得这些多功能磁性复合材料成为控制燃煤电厂汞排放的优秀候选吸附剂。
Magnetic zeolite composites with supported silver nanoparticles are a new class of multifunctional materials with potential applications as recyclable catalysts, disinfectants, and sorbents. This study evaluated the suitability of the magnetic composites as sorbents for the removal of elemental mercury vapor from flue gases of coal-fired power plants. The sorbents were found to completely capture mercury at temperatures up to 200 degrees C, and the mercury capacity of the sorbents was found to be affected by the state, content, and size of the silver particles in the composite. Cumulative or extended thermal treatments at 400 degrees C were found to improve the mercury capture capacity, allowing the sorbent to be regenerated and recycled multiple times without performance degradation. The magnetic sorbent was readily separated from fly ash by magnetic separation, leaving the fly ash essentially free of sorbent contamination. In initial in-plant tests, the sorbents were able to capture mercury from the flue gases of an operational, full-scale, coal-fired power plant. The combination of mercury capacity, ease of separation and regeneration, and recyclability makes these multifunctional magnetic composites excellent candidate sorbents for the control of mercury emissions from coal-fired power plants.