静电除尘器和湿法烟气脱硫装置对烟气汞形态的影响与控制  

Influence and Control of Electrostatic Precipitators and Wet Flue Gas Desulfurization Systems on the Speciation of Mercury in Flue Gas

作　　者：胡长兴[1] 周劲松[2] 何胜[2] 张乐[2] 郑剑铭[2] 骆仲泱 岑可法[2] 

机构地区：[1]浙江大学宁波理工学院,宁波315100 [2]浙江大学能源清洁利用国家重点实验室,杭州310027

出　　处：《动力工程》2009年第4期400-404,共5页Power Engineering

基　　金：国家自然科学基金资助项目(50476056);国家重点实验室开放基金资助项目(ZJUCEU2007006)

摘　　要：利用安大略标准方法和在线汞监测技术对6套典型燃煤电站锅炉静电除尘器(ESP)和湿法烟气脱硫(WFGD)装置前后烟气汞的浓度及形态进行了测试,并研究了2种装置对烟气汞形态转化的影响及其汞控制能力.结果表明:ESP对飞灰的捕获直接降低了烟气中颗粒汞的比例,从已测试的典型燃煤锅炉来看,ESP前的燃煤烟气中颗粒汞的平均比例在30%左右,经ESP后颗粒汞所占比例降至5%左右;经WFGD装置洗涤后,烟气中汞的形态发生了较大的改变,二价汞基本被捕获,进入WFGD装置的烟气中二价汞的比例越高,WFGD装置对烟气汞的脱除效率也越高.配置有选择性催化还原(SCR)脱硝装置+ESP+WFGD尾部烟气处理装置的燃煤电厂,能够很好地控制燃煤烟气汞的排放.Tests were carried out for the concentration and speciation of mercury in the flue gas before and after 6 sets of typical electrostatic precipitator （ESP） and wet flue gas desulfurization （WFGD） system of coal fired power stations by use of Ontario Hydro method and on-line mercury monitoring technology. The influence and control ability of the two devices on speciation transformation of mercury in the flue gas were also studied. Results show that collection of fly ash by ESP directly decreases the proportion of particle mercury in the flue gas. For the typical coal-fired boilers that had been tested, the average proportion of particle mercury in coal-fired flue gas before ESP is about 30 %, and decreases tO about 5 %after ESP. The speciation of mercury in the flue gas changes greatly after being washed by WFGD system. Almost all of the bivalent mercury is captured. The higher the proportion of bivalent mercury is in the flue gas entering the WFGD system, the higher the efficiency is for the mercury removal in the flue gas by WFGD system. The coal-fired power plants equipped with disposal devices for tail flue gas, such as selective catalytic reduction （SCR） denitrator ＋ESP＋WFGD, can well control the mercury emission from the flue gas.

关 键 词：燃煤 汞 静电除尘 湿法脱硫 形态 控制 

分 类 号：TQ534.9[化学工程—煤化学工程] X701[环境科学与工程—环境工程]