Enhanced Mercury Removal Technology in Coal-Fired Power Plants Through Desulfurization Wastewater Evaporation

doi:10.11930/j.issn.1004-9649.201711270

Abstract

Abstract: It is difficult to treat Wet Flue Gas Desulfurization (WFGD) wastewater of coal-fired power plant due to its complex compositions. In this paper, take a 600 MW supercritical unit as the research object, desulfurization wastewater evaporation technology is used to enhance the removal of gaseous mercury (Hg) for coal-fired power plants and the feasibility of synergistic mercury removal is explored. Effects of desulfurization wastewater chlorine ion concentration and unit load on Hg removal were studied as well. The results show that WFGD wastewater evaporation is beneficial to improve the efficiency of Hg oxidation and removal because Hg enriched with chlorine ions is easier to be removed. Hence this method realizes WFGD wastewater zero discharge and simultaneously enhances Hg removal efficiency. In addition, the mercury removal efficiency is greatly affected by chlorine ion concentration in desulfurization wastewater. When the chlorine ion concentration was increased from 21 250 mg/L to 36 500 mg/L, the mercury removal efficiency dropped from 95% to 58%. The synergistic mercury removal performance is slightly lower compared with the high loading conditions.

Key words: coal-fired unit, mercury, desulfurization wastewater, duct evaporation, chlorine ions, HCl

CLC Number:

X701.3
TM628

CHEN Kunyang, GUO Tingting, JIA Xibu, CAO Fan, YUAN Yuan. Enhanced Mercury Removal Technology in Coal-Fired Power Plants Through Desulfurization Wastewater Evaporation[J]. Electric Power, 2018, 51(10): 139-144.

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URL: https://www.electricpower.com.cn/EN/10.11930/j.issn.1004-9649.201711270

https://www.electricpower.com.cn/EN/Y2018/V51/I10/139

References

[1] 刘玉坤, 禚玉群, 陈昌和, 等. 燃煤电站脱硫系统的脱汞性能[J]. 中国电力, 2011, 44(12):68-72 LIU Yukun, ZHUO Yuqun, CHEN Changhe, et al. Mercury removal performance of desulfurization systems in coal-fired power plants[J]. Electric Power, 2011, 44(12):68-72
[2] 张静怡. 燃煤电站烟气中汞脱除与减排技术[J]. 中国电力, 2012, 45(9):76-79 ZHANG Jingyi. Technology of mercury removal and reduction for flue gas of coal-fired power plants[J]. Electric Power, 2012, 45(9):76-79
[3] SENIOR C L, SAROFIM A F, ZENG T, et al. Gas-phase transformations of mercury in coal-fired power plants[J]. Fuel Processing Technology, 2000, 63(2):197-213.
[4] 喻敏, 董勇, 王鹏, 等. 氯元素对燃煤烟气脱汞的影响研究进展[J]. 化工进展, 2012, 31(7):1610-1614 YU Min, DONG Yong, WANG Peng, et al. Progress of effects of chloride on mercury removal for coal-fired flue gas[J]. Chemical Industry and Engineering Progress, 2012, 31(7):1610-1614
[5] 吴江, 潘卫国, 任建兴, 等. 烟气汞形态分布及其受氯化物添加剂影响的研究[J]. 动力工程, 2009, 29(4):405-408 WU Jiang, PAN Weiguo, REN Jianxing, et al. Mercury speciation distribution in flue gas and the influence of chloride additive on it[J]. Journal of Power Engineering, 2009, 29(4):405-408
[6] 张梦泽. 氯化钙添加促进燃煤烟气汞形态转化的试验研究[D]. 济南:山东大学, 2014.
[7] 睢辉. 氯化镁调质烟气促进汞催化氧化的试验与机理研究[D]. 济南:山东大学, 2015.
[8] 马双忱, 于伟静, 贾绍广, 等. 燃煤电厂脱硫废水处理技术研究与应用进展[J]. 化工进展, 2016, 35(1):255-262 MA Shuangchen, YU Weijing, JIA Shaoguang, et al. Research and application progresses of flue gas desulfurization (FGD) wastewater treatment technologies in coal-fired plants[J]. Chemical Industry and Engineering Progress, 2016, 35(1):255-262
[9] 张志国, 胡大龙, 王璟, 等. 燃气电厂深度节水及废水零排放方案[J]. 中国电力, 2017, 50(7):127-132 ZHANG Zhiguo, HU Dalong, WANG Jing, et al. The in-depth water conservation and zero discharge technology for gas turbine power plants[J]. Electric Power, 2017, 50(7):127-132
[10] 郭东明. 脱硫工程技术与设备[M]. 北京:化学工业出版社, 2007.
[11] USEPA. Steam electric power generating point source category:final detailed study report, EPA 821-R-09-08[R]. 2009.
[12] WANG J, WANG T, MALLHI H, et al. The role of ammonia on mercury leaching from coal fly ash[J]. Chemosphere, 2007, 69(10):1586-1592.
[13] 孟素丽, 段钰锋, 黄治军, 等. 燃煤飞灰的物化性质及其吸附汞影响因素的试验研究[J]. 热力发电, 2009, 38(8):46-51 MENG Suli, DUAN Yufeng, HUANG Zhijun, et al. Experimental study on physicochemical characteristics and influencing factors of mercury adsorption by fly ash from coal combustion[J]. Thermal Power Generation, 2009, 38(8):46-51
[14] 高洪亮, 王向宇, 周劲松, 等. 静电除尘器对燃煤电站汞排放的影响[J]. 锅炉技术, 2007, 38(5):63-67 GAO Hongliang, WANG Xiangyu, ZHOU Jinsong, et al. The influence of ESP on mercury emission from coal-fired power plant[J]. Boiler Technology, 2007, 38(5):63-67
[15] WIDMER N C, COLE J A, SEEKER W R, et al. Practical limitation of mercury speciation in simulated municipal waste incinerator flue gas[J]. Combustion Science & Technology, 1998, 134(1-6):315-326.
[16] 赵永椿, 张军营, 刘晶, 等. 燃煤飞灰氧化汞的机制研究[J]. 科学通报, 2009(21):3395-3399 ZHAO Yongchun, ZHANG Junying, LIU Jing, et al. Mechanism of Hg oxidation by fly ash from coal combustion[J]. Chinese Science Bulletin, 2009(21):3395-3399
[17] 罗光前, 姚洪, 徐明厚, 等. 均相系统中汞的氧化实验与热力学平衡计算[J]. 工程热物理学报, 2007, 28(6):1039-1042 LUO Guangqian, YAO Hong, XU Minghou, et al. Experiments and thermodynamic equilibrium of homogenous oxidation of mercury[J]. Journal of Engineering Thermophysics, 2007, 28(6):1039-1042
[18] 杨应举, 屈文麒, 刘晶, 等. 燃煤烟气中Hg/Cl均相与非均相氧化机理[J]. 燃烧科学与技术, 2017, 23(1):10-14 YANG Yingju, QU Wenqi, LIU Jing, et al. Mechanism of homogeneous and heterogeneous Hg/Cl oxidation in coal-fired flue gas[J]. Journal of Combustion Science and Technology, 2017, 23(1):10-14
[19] 杨建平, 赵永椿, 张军营, 等. 燃煤电站飞灰对汞的氧化和捕获的研究进展[J]. 动力工程学报, 2014, 34(5):337-345 YANG Jianping, ZHAO Yongchun, ZHANG Junying, et al. Research process on mercury oxidation and capture with fly ash of coal-fired power plant[J]. Journal of Chinese Society of Power Engineering, 2014, 34(5):337-345
[20] 高洪亮, 周劲松, 骆仲泱, 等. 燃煤烟气中汞氧化的动力学机理[J]. 动力工程, 2007, 27(6):975-979 GAO Hongliang, ZHOU Jinsong, LUO Zhongyang, et al. The kinetic mechanism of mercury oxidation in coal combustion flue gas[J]. Journal of Power Engineering, 2007, 27(6):975-979
[21] 徐玮. 燃煤烟气中汞的形态分布特征及净化设备的除汞效果[D].上海:上海交通大学, 2010.