摘要
采用Ontario-Hydro方法和半连续汞排放监测仪,研究了电厂现有污染控制单元,选择还原催化(SCR)、静电除尘(ESP)、烟气脱硫(FGD)对烟气中汞的脱除能力。实验结果表明,在SCR催化剂V2O5/TiO2的作用下,50%以上的Hg0被氧化成Hg2+,但SCR本身不能控制汞释放量;ESP通过对飞灰的捕获直接降低了烟气中颗粒汞的比例;FGD依据Hg2+易溶于水的性质,通过吸收烟气中的Hg2+控制总汞的释放,部分Hg2+和FGD系统中的亚硫酸盐等发生反应,被还原为Hg0,发生了二次汞释放问题,造成脱汞整体效率降低。研究中考察了SCR开闭两种状态下整个系统汞的释放量,发现SCR单元启用时,由于烟气中Hg2+的浓度较高,二次汞释放现象更严重。
Ontario-Hydro method（OHM） and semi-continuous mercury emission（SCEM） were used to study the effects of the existing air pollutant control devices on mercury emission in coal-fired power plants.The results indicate that more than 50% of Hg0 is oxidized into Hg2＋ by selective catalytic（V2O5/TiO2） reduction（SCR）,but SCR itself couldn＇t control mercury emission.The collection of fly ash by electrostatic precipitator（ESP） directly lowers the proportion of particle mercury in the flue gas.For water soluble Hg2＋,wet flue gas desulphurization（FGD） could control mercury emission by absorbing Hg^2＋ in flue gas.Most of Hg^2＋ is reduced into Hg0 by reacting with SO32-and HSO3-in FGD slurry,which results in the decrease in mercury control efficiency.At the same time,it leads to the secondary emission of mercury,and it is more serious when SCR is in service.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2010年第6期641-646,共6页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金西部重大计划重点项目(9041010018)
教育部新世纪优秀人才支持计划(NCET2-052-0267)
关键词
燃煤电厂
烟气
选择还原催化单元
静电除尘单元
烟气脱硫单元
汞释放
coal-fired power plant
flue gas
selective catalytic reduction
electrostatic precipitator
flue gas desulphurization
mercury emission
