Zhang Cheng, Zhang Ya-Hui, Wang Yong-Min, Wang Ding-Yong, Xu Feng, Yang Xi, He Xiu-Qing
College of Resources and Environment, Southwest University, Chongqing 400715, China.
Chongqing Key Laboratory of Agricultural Resources and Environment, Chongqing 400715, China.
Huan Jing Ke Xue. 2017 Feb 8;38(2):495-501. doi: 10.13227/j.hjkx.201608055.
Four typical coal-fired power plants in Chongqing, representing two different boiler types (circulating fluidized bed boiler and pulverized coal boiler), were chosen to investigate mercury emission characteristics through a mercury mass balance method by analyzing mercury contents in all input and output raw materials in order to accurately estimate mercury emissions. The results showed coal with mercury concentrations ranging (80.77±6.39)-(266.83±4.71) μg·kg could be a significant contributor of input mercury in these four studied power plants. Most mercury output from these power plants entered into solid waste with high proportion of mercury entering the fly ash in CFB plants and entering the fly ash and desulfurization gypsum in PC plants. Mercury removal efficiencies of studied plants were in the range of 72.89%-96.05%, and these efficiencies in CFB plants were higher than those in PC plants. The mercury emission factors for EF and EF of these four plants were 4.66-29.47 μg·(kW·h) and 8.55-71.77 mg·t, respectively. The mercury emission was also calculated to be 6.13-429.17 g·d. Mercury emissions from coal-fired power plants were associated with the content of mercury in coal, boiler type, generation load, pollution control equipment, and so on. To control the mercury emissions, more attention should be paid to improving the generation load, increasing the mercury removal efficiency of flue gas cleaning equipment, and strengthening the supervision of solid waste re-utilization.
选取了重庆的4座典型燃煤电厂，代表两种不同的锅炉类型（循环流化床锅炉和煤粉锅炉），通过汞质量平衡法，分析所有输入和输出原材料中的汞含量，以准确估算汞排放量，从而研究汞排放特征。结果表明，汞浓度在（80.77±6.39）-（266.83±4.71）μg·kg之间的煤可能是这4座研究电厂汞输入的重要来源。这些电厂的大部分汞输出进入固体废物，其中循环流化床电厂中大部分汞进入飞灰，煤粉电厂中汞进入飞灰和脱硫石膏。研究电厂的汞去除效率在72.89%-96.05%之间，循环流化床电厂的汞去除效率高于煤粉电厂。这4座电厂的汞排放因子EF和EF分别为4.66-29.47μg·（kW·h）和8.55-71.77mg·t。计算得出汞排放量为6.13-429.17g·d。燃煤电厂的汞排放与煤中的汞含量、锅炉类型、发电负荷、污染控制设备等有关。为控制汞排放，应更加注重提高发电负荷、提高烟气净化设备的汞去除效率以及加强固体废物再利用的监管。
