Field Test And Estimation Of Mercury Emission From The Coal-fired Power Plant

The convenient and damage of the mankind living environment were simultaneous brought because of the large number of coal combustion. The mercury emission from coal-fired power plants has become the focus problem of the community during to the mercury and its compounds having the special properties and strong toxicity.The characteristics and estimation of mercury emission from the coal-fired power plant was studied in this paper. The basic operation of the coal quality, coal consuming, generated energy, boiler combustion modes and air pollution control devices were investigated. On this basis, the coal-fired power plants with the APCDs of the SCR+ESP/FF+WFGD、SCR+ESP+WFGD、ESP+WFGD、SCR+ESP+ organic amine desulfurization and SNCR + circulating fluidized bed+ESP/FF were chosen to research the mercury emission in field test. The method of US EPA 30 B and OHM were used for the parallel gas sampling in the chosen coal burning power plant, at the same time, the coal as fired, bottom slag, fly ash and gypsum slurry or sulfuric acid were sampled in spot. The contents of mercury in sampling were measured without pretreatment by the mercury analyzer of Lumex.The results shown that the range of the mercury content in coal-fired power plant were 99.33(ng/g) to 305.33(ng/g). The average is 206.60(ng/g) according to the mercury content in coal and the ratio of consumpted coal. Take for the coal-fired power plant of DF, the contents of mercury in bottom slag was very few and the percentages of mercury content in fly ash were 78.48, the ratio of mercury content in desulfurization gypsum was 18.17. In addition, the ratio of mercury content in purified flue gas was about 12.61. The collaborative mercury removal efficiencies of different APCDs according to the field test were the percentages of 26.62 to 97.56 and the range of mercury emission factor were 0.02 to 0.73. Compared to other APCDs, the configuration mode of SCR+ESP/FF+WFGD have a higher removal effects.Based on the operation situation of the coal-fired power plants and the analysis of the field test, we calculated that the average of mercury emission factor was 0.13. In addition, the weighted average of mercury content in coal was 206.60 ng/g, and the consumption of coal-fired in the tested filed during the year of 2013 was 5709.28 million tons, we estimated the total of mercury emission from the coal-fired power plant in tested province during the year of 2013 was approximately 1.49 tons.