论文部分内容阅读
In India coal combustion is the single largest source of emission of mercury which is a wide-spread persistent global toxicant,travelling across international borders through air and wa-ter.As a party to the Minamata convention,India aims to monitor and reduce Hg emissions and stricter norms are introduced for mercury emissions from power plants(30 μg/Nm3 for flue gas in stack).This paper presents the results obtained during the experimental studies performed on mercury emissions at four coal-fired and one lignite-fired power plants in India.The mer-cury concentration in the feed coal varied between 0.12-0.27 mg/Kg.In the mercury mass balance,significant proportion of feed coal mercury has been found to be associated with fly ash,whereas bottom ash contained very low mercury.80％-90％of mercury was released to air through stack gas.However,for circulating fluidised bed boiler burning lignite,about 64.8％of feed mercury was found to get captured in the fly ash and only 32.4％was released to air.The mercury emission factor was found to lie in the range of 4.7-15.7 mg/GJ.