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J4  2010, Vol. 44 Issue (9): 1773-1780    DOI: 10.3785/j.issn.1008-973X.2010.09.023
    
Effect of vanadiumbased selective catalytic reduction catalysts
on mercury speciation transformation
HE Sheng, ZHOU Jin-song, ZHU Yan-qun, LUO Zhong-yang,
NI Ming-jiang, CEN Ke-fa
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
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Abstract  

This work focused on the mercury speciation transformation across the selective catalytic reduction (SCR) system in coalfired power plants. The vanadiabased (V2O5/TiO2) SCR catalyst was synthesized by an impregnation method. The effects of vanadia loading, reaction temperature, flue gas components, NH3 and space velocity on mercury speciation transformation across the SCR were evaluated using a benchscale SCR reactor system. Results showed that the active component V2O5 in the SCR catalyst promoted the mercury oxidation by impacting the pool of vanadium active sites, which are critical for mercury oxidation. The activities of SCR catalyst for mercury oxidation are higher at higher temperature, 992% of mercury conversion is reached under test conditions. HCl is important for the mercury speciation transformation by providing the active Cl, which is responsible for the mercury oxidation. NH3 inhibits the mercury oxidation due to the competition for the active sites on the catalyst surface. Large space velocity is negative for the mercury speciation transformation.



Published: 01 September 2010
CLC:  X 511  
Cite this article:

HE Qing, ZHOU Jin-Song, SHU Yan-Qun, JIA Zhong-Yang, NI Meng-Jiang, CEN Ge-Fa. Effect of vanadiumbased selective catalytic reduction catalysts
on mercury speciation transformation. J4, 2010, 44(9): 1773-1780.

URL:

http://www.zjujournals.com/eng/10.3785/j.issn.1008-973X.2010.09.023     OR     http://www.zjujournals.com/eng/Y2010/V44/I9/1773


钒系SCR催化剂对汞形态转化的影响

为研究燃煤电站选择性催化还原(SCR)系统对烟气汞形态转化的作用,通过浸渍法制备钒系(V2O5/TiO2) SCR催化剂,利用实验室SCR汞形态转化试验台研究催化剂钒(V)负载量、反应温度、烟气组分、氨气和空速等因素对汞形态转化反应的影响.结果表明:V2O5负载量的增大在其表面形成更多的V活性中心位,促进汞形态的转化;在试验条件下,SCR催化剂活性随温度升高而增强,最大汞转化率达992%;烟气中的HCl为汞氧化反应提供所需的活性Cl原子;NH3与汞氧化反应组分在催化剂表面发生竞争吸附,抑制了汞氧化反应的发生;空速增大不利于汞的形态转化.

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