State Key Joint Laboratory of Environmental Simulation and Pollution Control, School of Environment, Beijing Normal University Beijing, PR China.
J Air Waste Manag Assoc. 2012 May;62(5):576-86. doi: 10.1080/10962247.2012.663733.
Atmospheric mercury (Hg) emission from coal is one of the primary sources of anthropogenic discharge and pollution. China is one of the few countries in the world whose coal consumption constitutes about 70% of total primary energy, and over half of coals are burned directly for electricity generation. Atmospheric emissions of Hg and its speciation from coal-fired power plants are of great concern owing to their negative impacts on regional human health and ecosystem risks, as well as long-distance transport. In this paper, recent trends of atmospheric Hg emissions and its species split from coal-fired power plants in China during the period of 2000-2007 are evaluated, by integrating each plant's coal consumption and emission factors, which are classified by different subcategories of boilers, particulate matter (PM) and sulfur dioxide (SO2) control devices. Our results show that the total Hg emissions from coal-fired power plants have begun to decrease from the peak value of 139.19 t in 2005 to 134.55 t in 2007, though coal consumption growing steadily from 1213.8 to 1532.4 Mt, which can be mainly attributed to the co-benefit Hg reduction by electrostatic precipitators/fabric filters (ESPs/FFs) and wet flue gas desulfurization (WFGD), especially the sharp growth in installation of WFGD both in the new and existing power plants since 2005. In the coming 12th five-year-plan, more and more plants will be mandated to install De-NO(x) (nitrogen oxides) systems (mainly selective catalytic reduction [SCR] and selective noncatalytic reduction [SNCR]) for minimizing NO(x) emission, thus the specific Hg emission rate per ton of coal will decline further owing to the much higher co-benefit removal efficiency by the combination of SCR + ESPs/FFs + WFGD systems. Consequently, SCR + ESPs/FFs + WFGD configuration will be the main path to abate Hg discharge from coal-fired power plants in China in the near future. However advanced specific Hg removal technologies are necessary for further reduction of elemental Hg discharge in the long-term.
大气汞（Hg）排放来自煤炭是人为排放和污染的主要来源之一。中国是世界上少数煤炭消费约占总初级能源的 70%，并且超过一半的煤炭直接用于发电的国家之一。由于对区域人类健康和生态系统风险以及远距离传输的负面影响，燃煤电厂大气汞及其形态的排放受到极大关注。在本文中，通过整合每个工厂的煤炭消耗和排放因子，评估了 2000-2007 年期间中国燃煤电厂大气 Hg 排放及其物种分裂的最新趋势，这些因子按不同的锅炉、颗粒物（PM）和二氧化硫（SO2）控制设备的子类别进行了分类。我们的结果表明，尽管煤炭消耗从 2005 年的 1213.8Mt 稳步增长到 2007 年的 1532.4Mt，但燃煤电厂的总 Hg 排放量已从 2005 年的 139.19t 峰值开始下降，这主要归因于静电除尘器/织物过滤器（ESP/FFs）和湿法烟气脱硫（WFGD）带来的协同汞减排效应，特别是自 2005 年以来，新老电厂 WFGD 的急剧增长。在未来的第十二个五年计划中，将有越来越多的工厂被要求安装脱硝（NOx）（主要是选择性催化还原[选择性非催化还原[SCR]和 SNCR]）系统以最大限度地减少 NOx 排放，因此，由于 SCR+ESP/FF+WFGD 系统的协同去除效率更高，每吨煤的特定 Hg 排放量将进一步下降。因此，在不久的将来，SCR+ESP/FF+WFGD 配置将成为中国燃煤电厂减少 Hg 排放的主要途径。然而，在长期内，需要先进的特定 Hg 去除技术来进一步减少元素 Hg 的排放。
