Study on Mercury Emissions and Ash Characteristics of 600 MW Brown Coal-Fired Unit

doi:10.12096/j.2096-4528.pgt.22074

Abstract

Abstract:

The mercury migration and conversion characteristics of the lignite unit is not clear. The mercury concentration were measured by 30B method at five flue gas sampling points (before and after SCR, before low-temperature economizer, before and after desulfurization) in Inner Mongolia Guohua Hulunbuir Power Generation Co., Ltd. The emission concentration of mercury in the flue gas at the stack is 6.16, 4.53 and 2.98 μg/m³ at 319, 450, 550 MW, respectively. The emission concentration of mercury in flue gas decreases with the increase of unit load. In addition, the pollutant control devices have a synergistic effect on the mercury removal and the co-control efficiency is 31.48%, 29.68% and 66.65% at 319, 450, 550 MW. According to the mercury balance calculation, it can be found that after coal combustion, most of the mercury in the flue gas is discharged into the atmosphere (44.85%-65.27%), followed by fly ash (27.81%-51.15%) and gypsum (3.95%-14.61%). The fly ash test results indicate that the hardness value is between 0.28-7.15 GPa. The study results provide the basic data for further deep removal mercury from flue gas of coal-fired power plant.

Key words: coal-fired power plant, mercury, lignite, on-site sampling, balance calculation

CLC Number:

TK 09

Zhigang GAO, Fuchun CHEN, Jiawei WANG, Tao WANG, Yongsheng ZHANG. Study on Mercury Emissions and Ash Characteristics of 600 MW Brown Coal-Fired Unit[J]. Power Generation Technology, 2023, 44(4): 543-549.

Figures/Tables 12

References 17

1	翁麒宇，李端乐，禚玉群．NH₃对SCR催化剂Hg⁰催化氧化性能的影响[J]．发电技术，2020，41(5)：471-479． doi:10.12096/j.2096-4528.pgt.20059
	WENG Q Y， LI D L， ZHUO Y Q ．Influence of NH₃ on Hg⁰ oxidation performance of SCR catalyst[J]．Power Generation Technology，2020，41(5)：471-479． doi:10.12096/j.2096-4528.pgt.20059
2	安晓雪，苏胜，向军，等．燃煤烟气中Hg迁移转化特性研究[J]．发电技术，2020，41(5)：489-496． doi:10.12096/j.2096-4528.pgt.20079
	AN X X， SU S， XIANG J，et al ．Hg formation and transformation characteristics in flue gas of coal-fired boiler[J]．Power Generation Technology，2020，41(5)：489-496． doi:10.12096/j.2096-4528.pgt.20079
3	陈招妹，刘含笑，崔盈，等．燃煤电厂烟气中Hg的生成、治理、测试及排放特征研究[J]．发电技术，2019，40(4)：355-361． doi:10.12096/j.2096-4528.pgt.19072
	CHEN Z M， LIU H X， CUI Y，et al ．Study on generation， treatment， testing and emission characteristics of Hg in flue gas of coal-fired power plants[J]．Power Generation Technology，2019，40(4)：355-361． doi:10.12096/j.2096-4528.pgt.19072
4	ZHONG L， ZHANG Y， JI Y，et al ．Synthesis of activated carbon from coal pitch for mercury removal in coal-fired power plants[J]．Journal of Thermal Analysis & Calorimetry，2016，123(1)：851-860． doi:10.1007/s10973-015-4966-5
5	中国环境科学研究院．火电厂大气污染物排放标准： [S]．北京：中国环境科学出版社，2012．
	Chinese Research Academy of Environmental Sciences ． Emission standard of air pollutants for thermal power plants： [S]．Beijing：China Environmental Science Press，2012．
6	田祎，徐克，王硕，等．我国汞和汞化合物临时贮存现状及环境无害化管理建议[J]．化工环保，2023，43(1)：132-136． doi:10.3969/j.issn.1006-1878.2023.01.020
	TIAN Y， XU K， WANG S，et al ．Current status of temporary storage of mercury and mercury compounds in China and suggestions for environmentally sound management[J]．Environmental Protection of Chemical Industry，2023，43(1)：132-136． doi:10.3969/j.issn.1006-1878.2023.01.020
7	潘伟平，张永生，李文瀚，等．燃煤汞污染监测及控制技术[J]．科技导报，2014，32(33)：57-60． doi:10.3981/j.issn.1000-7857.2014.33.007
	PAN W P， ZHANG Y S， LI W H，et al ．Mercury monitoring and controlling technologies for coal power plants[J]．Science& Technology Review，2014，32(33)：57-60． doi:10.3981/j.issn.1000-7857.2014.33.007
8	宋畅，张翼，郝剑，等．燃煤电厂超低排放改造前后汞污染排放特征［J］．环境科学研究，2017，30（5）：672-677． doi:10.13198/j.issn.1001-6929.2017.01.96
	SONG C， ZHANG Y， HAO J，et al ．Mercury emission characteristics from coal-fired power plant before and after ultra-low emission retrofitting[J]．Research of Environmental Sciences，2017，30(5)：672-677． doi:10.13198/j.issn.1001-6929.2017.01.96
9	郑楚光，张军营，赵永椿，等．煤燃烧汞的排放及控制[M]．北京：科学出版社，2010．
	ZHENG C G， ZHANG J Y， ZHAO Y C，et al ．Emission and control of mercury from coal combustion[M]．Beijing：Science Press，2010．
10	王家伟，张永生，张翼，等．喷射点位及温度对超低排放电厂活性炭吸附脱汞的影响[J]．中国电机工程学报，2019，39(11)：3303-3312．
	WANG J W， ZHANG Y S， ZHANG Y，et al ．Effects of temperature and residence time on mercury control using activated carbon injection in ultra-low emission coal-fired power plant[J]．Proceedings of the CSEE，2019，39(11)：3303-3312．
11	WANG S， ZHANG Y， GU Y，et al ．Coupling of bromide and on-line mechanical modified fly ash for mercury removal at a 1000 MW coal-fired power plant[J]．Fuel， 2019，247：179-186． doi:10.1016/j.fuel.2019.03.053
12	ZHANG Y， MEI D， WANG T，et al ．In-situ capture of mercury in coal-fired power plants using high surface energy fly ash[J]．Environmental Science & Technology，2019，53(13)：7913-7920． doi:10.1021/acs.est.9b01725
13	WANG Y J， DUAN Y F， YANG L G，et al ．Experimental study on mercury transformation and removal in coal-fired boiler flue gases[J]．Fuel Processing Technology，2009，90(5)：643-651． doi:10.1016/j.fuproc.2008.10.013
14	陶叶．火电机组烟气脱汞工艺路线选择[J]．电力建设，2011，32(4)：74-78． doi:10.3969/j.issn.1000-7229.2011.04.018
	TAO Y ．Process route selection of mercury control for coal-fired units[J]．Electric Power Construction，2011，32(4)：74-78． doi:10.3969/j.issn.1000-7229.2011.04.018
15	BURMISTRZ P， KOGUT K， MARCZAK M，et al ．Lignites and subbituminous coals combustion in Polish power plants as a source of anthropogenic mercury emission[J]．Fuel Processing Technology，2016，152：250-258． doi:10.1016/j.fuproc.2016.06.011
16	ZHANG Y， DUAN W， LIU Z，et al ．Effects of modified fly ash on mercury adsorption ability in an entrained-flow reactor[J]．Fuel，2014，128：274-280． doi:10.1016/j.fuel.2014.03.009
17	PENG Y， WANG T， GU Y，et al ．Impact of the mercury removal system using modified fly ash on particulate matter emission[J]．Fuel，2021，301：121054． doi:10.1016/j.fuel.2021.121054

负荷/MW	采样点位
负荷/MW	1	2	3	4	5
319	370	354	133	96	50
450	398	389	140	102	53
550	403	395	142	106	53

负荷/MW	采样点位
负荷/MW	1	2	3	4	5
319	370	354	133	96	50
450	398	389	140	102	53
550	403	395	142	106	53

负荷/MW	工业分析/%				元素分析/%					汞质量比/(ng/g)
负荷/MW	M_ad	V_ad	A_ad	F_cad	w（C）	w（H）	w（N）	w（S）	w（O）	汞质量比/(ng/g)
319	4.74	37.35	11.53	46.71	62.51	4.20	0.69	0.75	19.46	64.3±12.7
450	5.30	34.39	15.42	45.23	60.20	4.01	0.85	0.72	17.91	58.0±5.0
550	5.45	35.25	13.61	45.69	60.85	4.16	0.85	0.71	18.69	45.0±3.0

负荷/MW	工业分析/%				元素分析/%					汞质量比/(ng/g)
负荷/MW	M_ad	V_ad	A_ad	F_cad	w（C）	w（H）	w（N）	w（S）	w（O）	汞质量比/(ng/g)
319	4.74	37.35	11.53	46.71	62.51	4.20	0.69	0.75	19.46	64.3±12.7
450	5.30	34.39	15.42	45.23	60.20	4.01	0.85	0.72	17.91	58.0±5.0
550	5.45	35.25	13.61	45.69	60.85	4.16	0.85	0.71	18.69	45.0±3.0

负荷/MW	粗灰	细灰	炉渣	石膏	石灰石	污泥
319	198.7±13.6	140.7±11.9	0.1±0.1	65.7±14.6	10.1±1.7	486.7±11.0
450	109.3±14.2	115.0±9.5	0.1±0.0	208.3±12.5	11.3±1.5	—
550	190.3±4.0	130.0±11.3	0.1±0.0	52.3±0.6	6.9±1.6	—