火电厂烟气中汞的分布特征和排放特点

调查南京市某一燃煤火电厂100 MW机组,在两种不同的工况下,对该锅炉废气中的汞污染物进行现场测试,选取三个监测点位,分别为静电除尘器进口、出口及湿法脱硫装置出口,分析煤质燃烧烟气中汞不同形态的监测结果,得到静电除尘器和湿法脱硫装置对汞的脱除效率,总结火电厂烟气中汞的污染物的分布特征及其排放特点。火电厂燃烧的废气中汞来源于煤质中的汞,主要以气相部分汞形态存在,90%以上的汞以气态汞形态排放到烟气中,固相部分汞含量较少。静电除尘器对总汞有着相当高的脱除效率,湿法脱硫装置对总汞的脱除率较低。

Distribution and Emission Characteristics of Mercury in Flue Gas from Coal -fired Power Plant

This study investigated a IOOMW boiler unit of a coal - fired power plant in Nanjing. The mercury in exhaust were examined under two different conditions by selecting three monitoring sites of electrostatic precipitator, including, import, export and wet desulphurization system. Different monitoring results of mercury were analyzed. The removal rate of electrostatic precipitator and wet flue gas desulfurization equipment were obtained to summarize the distribution and emission characteristics of mercury in early flue gas. The mercury in exhausts are main in the form of gas mercury, more than 90 percent of the mercury are emitted in the gas. Electrostatic precipitator has a very high removal efficiency of total mercury, while that of wet desulfurization equipment is relatively low.