一座高灰无烟煤电厂的大气汞排放特征

生态学杂志

一座高灰无烟煤电厂的大气汞排放特征

唐黎^1,2,刘鸿雁¹,冯新斌²,李仲根^2*,傅成诚³,王浩³,陈吉²,王盛^4

(¹贵州大学资源与环境工程学院，贵阳 550025； ^2中国科学院地球化学研究所环境地球化学国家重点实验室，贵阳 550081； ³贵州省环境监测中心站，贵阳 550081； ^4中国地质大学（武汉）地球科学学院，武汉 430074）

出版日期:2016-05-10 发布日期:2016-05-10

Mercury emissions from a coal-fired power plant burning high ash content anthracite coal.

TANG Li^1,2, LIU Hong-yan¹, FENG Xin-bin², LI Zhong-gen^2*, FU Cheng-cheng³, WANG Hao³, CHEN Ji², WANG Sheng^4#br#

(¹College of Resource and Environmental Engineering, Guizhou University, Guiyang 550025, China; ²State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; ³Guizhou Environmental Monitoring Center, Guiyang 550081, China; ⁴Faculty of Earth Science, China University of Geosciences, Wuhan 430074, China).

Online:2016-05-10 Published:2016-05-10

摘要/Abstract

摘要： 燃煤电厂是我国当前最重要的大气汞排放源之一，而对于无烟煤电厂的研究不多。本研究通过安大略方法采集贵州省一座燃烧高灰无烟煤电厂的烟气，并同步采集煤炭、石灰石、底渣、飞灰、脱硫石膏等固体样品，对大气汞排放特征和汞质量平衡进行了现场测试。结果表明，锅炉类型和污染控制设施组合为煤粉炉+选择性催化还原脱硝+静电除尘+石灰石湿法脱硫的燃煤电厂，外排烟气汞平均含量为0.60 μg·m^-3，远低于国家燃煤电厂的汞排放标准30 μg·m^-3。由于煤炭灰分较高，导致该电厂汞在除尘前的烟气中主要以颗粒态为主，因此烟气中的大部分汞(84.57%)是通过静电除尘器脱除的，另外12.58%的汞是通过脱硫石膏脱除的，整个电厂的总汞脱除效率为97.15%，汞的排放因子为3.87 mg Hg·t^-1煤，处于已有报道的较低水平。最终外排的烟气82.7%为Hg⁰，16.6%为Hg²⁺，0.8%为Hg-P。

Abstract: Coal-fired power plant (CFPP) is one of the most important atmospheric mercury (Hg) sources in China, while studies on the burning anthracite coals of the CFPPs were inadequate. In this study, we investigated the atmospheric Hg emissions and mass balance of a CFPP that burned high ash content anthracite coal in southwestern China. Flue gas was sampled with the Ontario Hydro Method (OHM), and solid samples such as coal, limestone, bottom ash, fly ash, and gypsum were also collected. The CFPP is a pulverized coal (PC) boiler equipped with selective catalytic reduction (SCR), electrostatic precipitator (ESP) and wet flue gas desulfurization (WFGD). The results showed that total Hg content in the flue gas of the final discharging point was 0.60 μg·m^-3, much lower than the national emission limit (30 μg·m^-3). Due to the high ash content in the flue gas, particulate bounded mercury were the main form in flue gas before ESP, hence resulting in a high Hg removal efficiency through ESP. The total Hg removal efficiency for this CFPP was 97.15%, of which, 84.57% was obtained by ESP, 12.58% through WFGD. The Hg emission factor of this CFPP was 3.87 mg Hg·t^-1 coal, which was at lower level among those previously reported. Among the Hg emitted from the CFPP 82.7% was in gaseous elemental form (Hg⁰), 16.6% in gaseous oxidized form (Hg²⁺) and 0.8% in particulate bound form (Hg-P).

唐黎1,2,刘鸿雁1,冯新斌2,李仲根2*,傅成诚3,王浩3,陈吉2,王盛4. 一座高灰无烟煤电厂的大气汞排放特征[J]. 生态学杂志.

TANG Li1,2, LIU Hong-yan1, FENG Xin-bin2, LI Zhong-gen2*, FU Cheng-cheng3, WANG Hao3, CHEN Ji2, WANG Sheng4. Mercury emissions from a coal-fired power plant burning high ash content anthracite coal.[J]. cje.