• 关键词：烟气  单质汞  二价汞  颗粒汞  排放因子

• 基金项目：国家重点研发计划（No.2016YFC0203701）

• 赵毅
• 华北电力大学, 北京 102206

• 韩立鹏
• 1. 华北电力大学, 北京 102206;2. 国家能源煤炭清洁低碳发电技术研发实验中心(中国华能集团清洁能源技术研究院有限公司), 北京 102209

• 摘要：对某660 MW超低排放燃煤电站进行汞形态和浓度监测，实验结果表明：在SCR前烟气中，汞主要以单质游离态存在，SCR催化剂对Hg⁰氧化率约为20.22%.烟冷器内Hg⁰向Hg_p和Hg²⁺转化，Hg_p浓度增加72.18%，Hg²⁺浓度增加55.40%.低温电除尘不仅可以脱除Hg_p，对Hg⁰和Hg²⁺也具有协同脱除作用，Hg⁰浓度下降47.14%，Hg²⁺浓度下降68.70%.经过湿法脱硫后Hg⁰浓度由0.37 μg·m^-3升高到0.86 μg·m^-3，Hg²⁺在湿法脱硫装置内被还原为Hg⁰.大气汞排放浓度在0.82~0.95 μg·m^-3之间，远低于标准要求.超低排放电站产生的汞大部分进入粉煤灰（68.35%），大气排放的汞为21.20%，进入石膏中的汞为4.87%，进入脱硫废水处理站固废5.53%.超低排放环保设备总的协同脱汞效率为78.77%，大气汞排放因子（EF_煤、EF_电）分别为6.07 μg·kg^-1和1.70 μg·kW^-1·h^-1.

• Abstract：The speciation and quantity of mercury were monitored and tested in a 660 MW coal-fired power plant with ultra-low air pollutant control technologies. The results show that mercury is existed as elemental mercury(Hg⁰) before SCR and 20.22% elemental mercury (Hg⁰) are converted as oxidized mercury (Hg²⁺) by SCR catalyst. And Majority of Hg⁰ in low-temperature economizer was converted to Hg_p and Hg²⁺, the concentration of Hg_p and Hg²⁺ increased by 72.18% and 55.40% respectively. Low-low temperature ESP has the significantly synergistic removal of Hg⁰ and Hg²⁺, the concentration of Hg⁰ and Hg²⁺ decreased by 47.14% and 68.70% respectively. Besides, The concentration of Hg⁰ increase from 0.37 μg·m^-3 to 0.86 μg·m^-3 after WFGD, since Hg²⁺ is reduced to Hg⁰ in WFGD. The concentration of mercury emission is about 0.82~0.95 μg·m^-3, which is far below the national standards. Most of the mercury is left in fly ash, accounted for 68.35%, the rest of mercury is lest in the atmospheric emission with 21.20%, gypsum with 4.87%, and the desulfurization wastewater with 5.53%. In total, the mercury removal efficiency of ultra-low emission environmental protection equipment is 78.77%, Emission factors of mercury for coal and electricity of the power plant are 6.07 μg·kg^-1 and 1.70 μg·kW^-1·h^-1respectively.

• Key words：flue gas  elemental mercury  oxidized mercury  particulate mercury  emission factor

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