300 MW燃煤电厂ESP和WFGD对烟气汞的脱除特性

李志超; 段钰锋; 王运军; 黄治军; 孟素丽; 沈解忠

300 MW燃煤电厂ESP和WFGD对烟气汞的脱除特性

1.
东南大学能源热转换及其过程测控教育部重点实验室,能源与环境学院, 江苏南京 210096;
2.
常熟市第一人民医院, 江苏常熟 215500;
3.
无锡华光锅炉股份有限公司, 江苏无锡 214028

基金项目: 国家自然科学基金(51076030); 江苏省环保科研课题基金(201113); 煤燃烧国家重点实验室开放基金(FSKLCC1002).

详细信息

通讯作者:
段钰锋(1963-), 男, 教授, 主要从事燃煤大气污染防治研究, E-mail:yfduan@seu.edu.cn.

中图分类号: TQ534.9
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出版历程
- 收稿日期: 2012-08-02
- 修回日期: 2012-10-24
- 刊出日期: 2013-04-30

Mercury removal by ESP and WFGD in a 300 MW coal-fired power plant

1.
Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing 210096, China;
2.
Changshu No.1 People’s Hospital, Changshu 215500, China;
3.
Wuxi Huaguang Boiler Company Limited, Wuxi 214028, China

摘要

摘要: 采用燃煤电厂汞形态浓度取样测试OHM标准方法,对一座300 MW燃煤电厂静电除尘器(ESP)和湿法脱硫装置(WFGD)前后烟气进行了等速取样.使用美国Leeman Labs Hydra AA全自动汞分析仪检测烟气中的汞形态浓度.采集了固体样品,包括入炉煤、底渣、ESP电场灰、脱硫剂石灰石、脱硫产物石膏等,使用意大利Milestone公司生产的DMA80全自动汞分析仪检测固体样品中的汞浓度.计算锅炉系统的汞质量平衡,获得了ESP和WFGD前后烟气的汞形态浓度和分布规律,分析讨论了影响烟气汞形态转化的各种影响因素.结果表明,燃煤烟气中气态单质汞Hg⁰和气态氧化汞Hg²⁺占到总汞量的95%.煤渣中的汞可忽略不计;ESP对颗粒态汞Hg^p的脱除效率达到95%以上,但是对Hg⁰和Hg²⁺脱除率不高.ESP对烟气总汞Hg^T脱除效率为12.77%~17.38%;WFGD对Hg²⁺的脱除率达到79.93%~90.53%,但是对Hg⁰没有脱除效果,其含量不仅没有下降反而有少量上升,说明有部分Hg²⁺在WFGD中被还原成Hg⁰.WFGD对Hg^T脱除效率为9.68%~29.36%;该电厂现有污染控制设备ESP+WFGD可以脱除全部的Hg^p和大部分Hg²⁺,但是由于部分Hg²⁺的还原使得Hg^T的脱除效率在25.38%~38.38%.综合来看,该燃煤电厂的污染物控制设备在进行除尘和脱硫的同时,对汞的脱除率并不高,与燃煤中的氯含量较低有关.
- 燃煤电厂 /
- 汞质量平衡 /
- ESP /
- WFGD /
- 汞形态 /
- 脱汞效率
Abstract: The Ontario Hydro Method (OHM) was used to sample and analyze the mercury concentration in flue gas before and after ESP and WFGD in a 300 MW power plant. Mercury content in coal, bottom slag, fly ash of ESP, adsorbent (limestone) and desulfurization product (gypsum) was detected by DMA80. Mercury mass balance was calculated based on the online measurements through the boiler system. Factors affecting the distribution, transformation and removal of mercury in flue gas were discussed. The results show that the gaseous mercury (Hg⁰ and Hg²⁺) in flue gas accounts for about 95% of total mercury, while mercury in the bottom ash can be neglected. More than 95% of Hg^p and a little gaseous phase mercury (Hg⁰ and Hg²⁺)were removed by ESP. The efficiencies to remove total mercury by ESP range from 12.77% to 17.38%. A removal efficiency for Hg²⁺(g) reaches up to 79.93%~90.53% by WFGD, however, the content of Hg⁰ after WFGD increases because part of oxidized mercury is reduced to elemental mercury during WFGD. The efficiencies to remove total mercury by WFGD range from 9.68% to 29.36%. ESP and WFGD can remove all of the Hg^p and a majority of Hg²⁺ with a total mercury removal efficiency of 25.38%~38.38%. In general, the demercuration in the conventional devices of ESP and WFGD is not high, which perhaps is owing to the lower concentration of Cl in feed coal.
- coal-fired power plant /
- mercury mass balance /
- ESP /
- WFGD /
- mercury speciation /
- demercuration efficiency

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参考文献(20)

ZHENG Y J, JENSEN A D, WINDELIN C, JENSEN F. Review of technologies for mercury removal from flue gas from cement production processes[J]. Prog Energy Combust Sci, 2012, 38(5): 599-629.

US EPA. A study of hazardous air pollutant emissions from electric utility steam generating units: Final report to congress, EPA-453/R-98-004a. Washington, D.C.: U.S. EPA, February 1998.

蒋靖坤, 郝吉明, 吴烨, STREETS D G, 段雷, 田贺忠. 中国燃煤汞排放清单的初步建立[J]. 环境科学, 2005, 26(2): 34-39. (JIANG Jing-kun, HAO Ji-ming, WU Ye, STREETS D G, DUAN Lei, TIAN He-zhong. Development of mercury emission inventory from coal combustion in China[J]. Environmental Science, 2005, 26(2): 34-39.)

STREETS D G, HAO J M, WU Y, JIANG J K, CHAN M, TIAN H Z, FENG X B. Anthropogenic mercury emissions in China[J]. Atmos Environ, 2005, 39(40): 7789-7806.

WU Y, WANG S X, STREETS D G, HAO J M,CHAN M, JIANG J K. Trends in anthropogenic mercury emissions in China from 1995 to 2003[J]. Environ Sci Technol, 2006, 40(17): 5312-5318.

胡长兴, 周劲松, 何胜, 骆仲泱, 岑可法. 全国燃煤电站汞排放量估算[J]. 热力发电, 2010, 39(2): 1-4. (HU Chang-xing, ZHOU Jin-song, HE Sheng, LUO Zhong-yang, CEN Ke-fa.Estimation of mercury emission from coal-fired power plants in China[J]. Thermal Power Generation, 2010, 39(2): 1-4.)

TIAN H Z, WANG Y, XUE Z G, CHENG K, QU Y P, CHAI F H, HAO J M. Trend and characteristics of atmospheric emissions of Hg, As, and Se from coal combustion in China,1980-2007[J]. Atmos Chem Phys, 2010, 10(9): 11905-11919.

US EPA. Standards of performance for new and existing stationary sources: Electric utility stream generating units[S]. Washington, D.C.: U.S. EPA, March 2005.

WANG S X, ZHANG L, LI G H, WU Y, HAO J M, PIRRONE N, SPROVIERI F, ANCORA M P. Mercury emission and speciation of coal-fired power plants in China[J]. Atmos Chem Phys, 2010, 10(3): 1183-1192.

US EPA. Standard test method for elemental, oxidized, particle-bound, and total mercury in flue gas generated from coal-fired stationary sources (Ontario Hydro Method)[S]. Washington, D.C.: U.S. EPA, September 2001.

王运军. 燃煤烟气汞形态转化及汞吸附机理研究. 南京: 东南大学博士学位论文, 2010. (WANG Yun-jun. Study on mercury speciation transformation and adsorption mechanism in coal-fired flue gas. Nanjing: Southeast University, 2010.)

YOKOYAMA T, ASAKURA K, MATSUDA H, ITO S, NODA N. Mercury emissions from a coal fired power plant in Japan[J]. Sci Total Environ, 2000, 259 (1-3): 97-103.

齐立强. 燃煤锅炉微细颗粒电除尘特性及电场逃逸机理的研究. 北京: 华北电力大学博士学位论文, 2006. (QI Li-qiang. Study on the electrostatic precipitatability and escape mechanism of the fine particulate from electrostatic precipitator of coal-fired boilers. Beijing: North China Electric Power University, 2006.)

KILGROE J D, SEDMAN C B, SRIVASTAVA R K, RYAN J V, LEE C W, THORNELOE S A. Control of mercury emissions from coal-fired electric utility boilers: Interim report,EPA-600/R-01-109. Washington, D.C.:U.S. EPA, December, 2001.

RICHARDSON M K, BLYTHE G M, GOLDEN D. Mercury stability in FGD byproducts. In: Combined Power Plant Air Pollutant Control Mega Symposium,Washington, D.C.,May, 2003.

CHANG J C, GHORISHI S B.Simulation and evaluation of elemental mercury concentration increase in flue gas across a wet scrubber[J]. Environ Sci Technol, 2003, 37(24): 5763-5766.

GOODARZI F. Characteristics and composition of fly ash from Canadian coal-fired power plants[J]. Fuel, 2006, 85(10/11): 1418-1427.

WU S J, UDDI M A, SASAOKA E. Characteristics of the removal of mercury vapor in coal derived fuel gas over iron oxide sorbents[J]. Fuel, 2006, 85(2): 213-218.

KELLIE S, CAO Y, DUAN Y F, LI L C, CHU P, MEHTA A, CARTY R, RILEY J T, PAN W P. Factors affecting mercury speciation in a 100-MW coal-fired boiler with low-NO_x burners[J]. Energy Fuels, 2005, 19(3): 800-806.

MILLER S M, NESS S R, WEBER G F, ERICKSON T A, HASSETT D J, HAWTHORNE S B, KATRINAK K A, LOUIE P K. A comprehensive assessment of toxic emissions from coal-fired power plants: Phase I results from the U.S. department of energy study. Grand Forks, North Dakota: Energy and Environmental Research Center (EERC), University of North Dakota, September 1996.

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