Removal of elemental mercury from flue gas using sargassum chars modified by NH 4 Br reagent
Removal of elemental mercury from flue gas using sargassum chars modified by NH 4 Br reagent
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DOI：
10.1016/j.fuel.2017.11.004
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发表时间：
2018-02
期刊：
影响因子：
7.4
通讯作者：
Wei Yang;Ziyang Liu;Wen Xu;Yangxian Liu
中科院分区：
文献类型：
--
作者：
Wei Yang;Ziyang Liu;Wen Xu;Yangxian Liu
海洋蕴藏着巨大的生物质资源。积极开发海洋生物质资源对人类发展具有重要意义。本研究以一种海藻--马尾藻为原料，采用热解法制备半焦。采用简单的浸渍法，用NH 4 Br试剂对马尾藻焦进行改性，并将其用于烟气中Hg 0的捕集。采用扫描电镜（SEM）、工业元素分析、X射线光电子能谱（XPS）和比表面积（BET）等方法对样品的理化性质进行了研究。研究了热解温度、反应温度、负荷值以及烟气中O2、水蒸气、NO和SO2等组分对脱汞效果的影响。对汞的脱除机理、动力学和热力学进行了研究。结果表明，提高热解温度、反应温度、负载量、O2浓度和NO浓度均有利于汞的脱除。低浓度的SO2和H2O有利于汞的去除，高浓度的SO2和H2O会抑制汞的去除。C-Br和C=O共价基团是Hg 0去除的主要化学吸附位点。最后，还获得了汞去除的动力学和热力学参数。
Ocean contains huge biomass resources. Actively developing marine biomass resources has great significance to human development. In this work, a kind of seaweed, sargassum, is used to prepare chars by pyrolysis. The sargassum chars are modified by NH4Br reagents using a simple impregnation method, and are applied to capture Hg0from flue gas. The physicochemical properties of the samples are investigated using scanning electron microscopy (SEM), proximate and ultimate analysis, X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET), respectively. The effects of pyrolysis temperature, reaction temperatures, loading values and the components of flue gas such as O2, water vapor, NO and SO2on mercury removal efficiency are studied. Mercury removal mechanism, kinetics and thermodynamics are also investigated. The results show that increasing pyrolysis temperature, reaction temperature, loading value, O2concentration and NO concentration enhances mercury removal. Low concentrations of SO2and H2O are beneficial to mercury removal, and high concentrations of SO2and H2O inhibit mercury removal. C-Br and C=O covalent groups are the major chemisorption sites for Hg0removal. Finally, the kinetic and thermodynamic parameters of mercury removal are also obtained.