Please wait a minute...
JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE)
    
Catalytic oxidation experiment of element mercury over Cr/TiO2 catalyst
YU Jin pin, QIU Kun zan, SONG Hao, GAO Xiang, ZHOU Jin song
State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China
Download:   PDF(1537KB) HTML
Export: BibTeX | EndNote (RIS)      

Abstract  

A series of Cr/TiO2 catalysts with different Cr loading w(0.1%~5%) were prepared using impregnation method. Cr/TiO2 catalysts exhibit excellent mercury oxidation ability in low HCl concentration even at high gas hourly space velocity. The influences of Cr loading, reaction temperature and flue gas component on mercury oxidation were studied as well. The results indicate that mercury oxidation increase together with the increase of Cr content and reaction temperature. O2 and HCl have  significant promoting effect on mercury oxidation over Cr/TiO2 catalyst. The reaction over Cr/TiO2 catalyst follows Mars Maessen mechanism when only O2 exists. Hg0  initially adsorbs on the catalyst surface, then reacts with lattice oxygen to form weakly adsorbed HgO. The consumed lattice oxygen is recovered by gas phase oxygen. When both O2 and HCl  exist, mercury oxidation is promoted due to active chlorine species generated on the catalyst surface and the mechanism alters. NO is also found to promote mercury oxidation. SO2 however inhibits the reaction due to its competitive adsorption with Hg0 on catelytic surface. H2O is also found to have a negative effect on mercury oxidation.



Published: 01 November 2015
CLC:  X 701  
Cite this article:

YU Jin pin, QIU Kun zan, SONG Hao, GAO Xiang, ZHOU Jin song. Catalytic oxidation experiment of element mercury over Cr/TiO2 catalyst. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2015, 49(11): 2186-2192.

URL:

http://www.zjujournals.com/eng/10.3785/j.issn.1008 973X.2015.11.021     OR     http://www.zjujournals.com/eng/Y2015/V49/I11/2186


Cr/TiO2催化剂汞氧化的实验

通过等体积浸渍法制备不同质量分数w(0.1%~5%)的Cr/TiO2催化剂.活性测试结果表明,Cr/TiO2催化剂在高空速、低氯条件下有很高的汞氧化活性.研究Cr负载量、反应温度、不同烟气组分对汞氧化的影响,结果表明:Cr/TiO2催化剂汞氧化活性随Cr负载量和反应温度的升高而提高.O2和HCl对Cr/TiO2催化剂上汞氧化有极强的促进作用.当只有O2存在时,Cr/TiO2催化剂上汞氧化按照Mars Maessen机理进行,Hg0首先吸附到催化剂表面,然后与晶格氧反应生成弱吸附的HgO,消耗的晶格氧由气态O2补充.当O2和HCl同时存在时,由于在催化剂表面生成活性氯物种,反应机理发生改变,汞氧化得到促进.NO也可以促进汞氧化.SO2与Hg0在催化剂表面竞争吸附从而抑制汞氧化,H2O对汞氧化也有抑制作用.

[1] REDDY B, DURGASRI N, KUMAR T, et al.Abatement of gas phase mercury—recent developments[J].Catalysis Reviews,2012,54:344-398.
[2] United Nations Environment Programme. Global mercury assessment 2013: sources, emissions, releases and environmental transport[R].Geneva: Switzerland UNEP Chemicals Branch, 2013.
[3] United States Environmental Protection Agency. Mercury and air toxics standards (MATS) [EB/OL].(2015 9 25) [2015 10 7]. http://www.epa.gov/airquality/powerplanttoxics/actions.html.
[4] GALBREATH K, ZYGARLICKE C.Mercury transformations in coal combustion flue gas[J].Fuel Processing Technology,2000,65:289-310.
[5] PAVLISH J, SONDREAL E, MANN M, et al.Status review of mercury control options for coal fired power plants [J].Fuel Processing Technology,2003,82:89-165.
[6] WU Sheng ji, OZAKI M, UDDIN M, et al.Development of iron based sorbents for Hg0 removal from coal derived fuel gas: Effect of hydrogen chloride[J].Fuel,2008,87:467-474.
[7] JI Lei, SREEKANTH P, SMIRNIOTIS P, et al.Manganese oxide/titania materials for removal of NOx and elemental mercury from flue gas[J].Energy & Fuels,2008,22:2299-2306.
[8] XIE Jiang kun, YAN Nai qiang, YANG Shi jian, et al.Synthesis and characterization of nano sized Mn–TiO2 catalysts and their application to removal of gaseous elemental mercury [J].Research on Chemical Intermediates,2012,38:2511-2522.
[9] LIU Yue, WANG Yue jun, WANG Hai qiang, et al.Catalytic oxidation of gas phase mercury over Co/TiO2catalysts prepared by sol–gel method [J].Catalysis Communications,2011,12:1291-1294.
[10] KIM M, HAM S, LEE J.Oxidation of gaseous elemental mercury by hydrochloric acid over CuCl2/TiO2 based catalysts in SCR process [J].Applied Catalysis B: Environmental,2010,99:272-278.
[11] AGLULIN A.Kinetics and possible mechanism of HCl oxidation on chromium containing catalysts [J].Kinetics and Catalysis,1998,39:521-529.
[12] AMRUTE A, MONDELLI C, PEREZ RAMIREZ J.Kinetic aspects and deactivation behaviour of chromia based catalysts in hydrogen chloride oxidation [J].Catalysis Science & Technology,2012,2:2057-2065.
[13] STRAUBE S, HAHN T, KOESER H.Adsorption and oxidation of mercury in tail end SCR DeNOx plants—Bench scale investigations and speciation experiments[J].Applied Catalysis B: Environmental,2008,79:286-295.
[14] LEE C, SERRE S, ZHAO Y, et al.Mercury oxidation promoted by a selective catalytic reduction catalyst under simulated Powder River Basin coal combustion conditions [J].Journal of the Air & Waste Management Association,2008,58:484-493.
[15] RALLO M, HEIDEL B, BRECHTEL K, et al.Effect of SCR operation variables on mercury speciation[J].Chemical Engineering Journal,2012,198 199:87-94.
[16] GRANITE E, PENNLINE H, HARGIS R.Novel sorbents for mercury removal from flue gas[J].Industrial & Engineering Chemistry Research,2000,39:1020-1029.
[17] CAO Yan, CHEN Bobby, WU Jiang, et al.Study of mercury oxidation by a selective catalytic reduction catalyst in a pilot scale slipstream reactor at a utility boiler burning bituminous coal [J].Energy & Fuels,2007,21:145-156.
[18] FAN Xiao peng, LI Cai ting, ZENG Guang ming, et al.Hg0 Removal from simulated flue gas over CeO2/HZSM 5 [J].Energy & Fuels,2012,26:2082-2089.
[19] LI Hai long, WU Chang Yu, LI Ying, et al.CeO2 TiO2 Catalysts for catalytic oxidation of elemental mercury in low rank coal combustion flue gas[J].Environmental Science & Technology,2011,45:7394-7400.
[20] LI Ying, MURPHY P, WU Chang Yu, et al.Development of silica/vanadia/titania catalysts for removal of elemental mercury from coal combustion flue gas[J].Environmental Science & Technology,2008,42:5304-5309.
[21] LI Ying, MURPHY P,WU Chang Yu.Removal of elemental mercury from simulated coal combustion flue gas using a SiO2–TiO2 nanocomposite [J].Fuel Processing Technology,2008,89:567-573.
[22] ESWARAN S,STENGER H.Understanding mercury conversion in selective catalytic reduction (SCR) catalysts [J].Energy & Fuels,2005,19:23282334.
[23] FAN Xiao peng, LI Cai ting, ZENG Guang ming, et al.Removal of gas phase element mercury by activated carbon fiber impregnated with CeO2[J].Energy & Fuels,2010,24:4250-4254.
[24] WEN Xiao yu, LI Cai ting, FAN Xiao peng, et al.Experimental study of gaseous elemental mercury removal with CeO2/gamma Al2O3[J].Energy & Fuels,2011,25:2939-2944.
[25] ZHUANG Ye, LAUMB J, LIGGETT R, et al.Impacts of acid gases on mercury oxidation across SCR catalyst [J].Fuel Processing Technology,2007,88:929-934.
[26] LI Hai long, WU Chang Yu, LI Ying, et al.Role of flue gas components in mercury oxidation over TiO2 supported MnOx CeO2 mixed oxide at low temperature[J].Journal of Hazardous Materials,2012,243:117-123.
[27] ZHANG An chao, ZHENG Wen wen, SONG Jun, et al.Cobalt manganese oxides modified titania catalysts for oxidation of elemental mercury at low flue gas temperature [J].Chemical Engineering Journal,2014,236:29-38.

[1] XU Xi, XU Dian, YAN Pei, ZHU Wei-zhuo, ZHENG Cheng-hang, GAO Xiang, LUO Zhong-yang, NI Ming-jiang, CEN Ke-fa. Particle collection in wire-plate electrostatic precipitators at high temperature[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2017, 51(3): 487-493.
[2] LIN Fa-wei, ZHU Yan-qun, XU Chao-qun, MA Qiang, WANG Zhi-hua, ZHOU Jun-hu, CEN Ke-fa. Experimental study on residual ozone decomposition in process of multi-pollutants removal by ozone[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2015, 49(7): 1249-1254.
[3] WAN Yi, HUANG Wei-wei, ZHENG Cheng-hang, GAO Xiang, CEN Ke-fa. Spray characteristics of wet electrostatic precipitator[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2015, 49(2): 336-343.
[4] WANG Hui-ting, DING Hong-lei, YAO Guo-xin, ZHANG Yong-xin,. Experimental study on SO2 absorption rate enhanced by additive in limestone-gypsum WFGD process[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2014, 48(1): 50-55.
[5] MAO Jian-hong,JIANG Xin-wei,ZHONG Yi,SONG Hao,WU Wei-hong,PAN Shu-ping,GAO Xiang. The effect of splitters layout at variable cross-section
inclined flue on AIG inlet flow field
[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2011, 45(8): 1453-1457.
[6] MAO Jian-hong,SONG Hao,WU Wei-hong,ZHONG Yi,GAO Xiang,LUO Zhong-yang,CEN Ke-fa. Design and optimization of splitters in SCR system for coal fired boiler[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2011, 45(6): 1124-1129.
[7] YANG Jian-tao, PAN Hua, CHEN Jie, SU Qing-fa, WANG Da-hui, SHI Yao. Two-stage system of non-thermal plasma and adsorption for
decomposition of hydrogen sulfide
[J]. JOURNAL OF ZHEJIANG UNIVERSITY (ENGINEERING SCIENCE), 2010, 44(12): 2411-2415.