Institute of Environmental Engineering and Management, National Taipei University of Technology, Taipei, Taiwan.
Green Energy and Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan.
J Air Waste Manag Assoc. 2021 May;71(5):553-563. doi: 10.1080/10962247.2020.1860158. Epub 2021 Feb 17.
In this study, the mercury (Hg) emission, speciation, and mass distribution of four coal-fired power plants (CFPPs) located at central, southern, and northern Taiwan with various types of air pollution control devices were investigated. Gaseous Hg in the coal-combustion flue gas was sampled by using the Ontario Hydro method, and the solid and liquid samples were collected for understanding the Hg mass balance. The experimental results showed that the total Hg concentrations in flue gases at the inlets of selective catalytic reduction (SCR) varied from 2.984 to 4.692 μg Nm, while the total Hg concentrations in the flue gases at the stacks ranged from 0.240 to 0.675 μg Nm. These four CFPPs showed similar Hg speciation results at the stacks. The average Hg removal efficiencies of Plants 1 (SCR + electrostatic precipitator [ESP] + wet flue gas desulfurization [WFGD]), 2 (SCR + ESP + WFGD), 3 (SCR + bag filter (BF) + seawater flue gas desulfurization [SWFGD]) and 4 (SCR + BF + SWFGD) were 92.4%, 90.1%, 85.9%, and 84.8%, respectively. Coal was the major raw material in Hg input of CFPPs with a mass flow rate ranging 5.87-12.05 g hr. Elemental Hg (Hg), accounting for 66.4%-97.1% of the total Hg, was the dominant species emitted to the atmosphere. The Hg mass balances for the four CFPPs varied from 86.0% to 117% of the Hg input, suggesting that good mass balances were obtained from the tested CFPPs.: Mercury emissions from coal-fired power plant (CFPPs) have been greatly concerned and should thus be better comprehended. The present study examined the mercury speciation and mass distribution of four CFPPs located at Taiwan. Overall, these CFPPs had similar Hg speciation results at stack and Hg was the dominant species emitted to the atmosphere. The selective catalytic reduction (SCR) + electrostatic precipitator (ESP) + wet flue gas desulfurization (WFGD) system had the highest Hg removal efficiency and the Hg mass balances for the four CFPPs varied from 86.0 to 117%. This study helps better understanding the Hg emission inventory of CFPPs and provides useful information for selecting adequate air pollution control devices (APCDs) for Hg control.
在这项研究中，我们调查了位于台湾中部、南部和北部的四家电厂（CFPP）的汞（Hg）排放、形态和质量分布情况，这些电厂采用了不同类型的空气污染控制设备。使用安大略水电法对燃煤烟道气中的气态汞进行采样，并采集固体和液体样品以了解汞的质量平衡。实验结果表明，选择性催化还原（SCR）入口处的烟道气中总汞浓度在 2.984 至 4.692μg Nm 之间，而烟囱处的烟道气中总汞浓度在 0.240 至 0.675μg Nm 之间。这四个 CFPP 的烟囱处 Hg 形态结果相似。工厂 1（SCR+静电除尘器[ESP]+湿法烟气脱硫[WFGD]）、2（SCR+ESP+WFGD）、3（SCR+袋式过滤器[BF]+海水烟气脱硫[SWFGD]）和 4（SCR+BF+SWFGD）的 Hg 去除效率分别为 92.4%、90.1%、85.9%和 84.8%。煤是 CFPPs 汞输入的主要原料，质量流速在 5.87-12.05g hr 之间。元素汞（Hg）占总汞的 66.4%-97.1%，是大气中主要排放的汞形态。四个 CFPP 的 Hg 质量平衡在 Hg 输入的 86.0%至 117%之间变化，这表明从测试的 CFPP 中获得了良好的质量平衡。
