Emission And Analysis Of Atmospheric Mercury In Coal-fired Power Plants In Shandong Province

Mercury is a highly toxic global pollutant that can stay in the atmosphere for a long time and can be transported at a long distance.Because of its bio-enrichment,it can adversely affect the ecological environment and human health.Therefore,people pay more attention to it.Coal combustion is the main source of atmospheric mercury,coal dominates China’s energy consumption.So China is also the world’s largest anthropogenic mercury emissions.As a big province of coal consumption in shandong province,is one of heavy pollution area in China,however,there are relatively few studies on atmospheric mercury emissions from coal-fired power plants,and the analysis of its emissions inventory research is at the blank stage.Therefore,the analysis of atmospheric mercury in coal-fired power plants in Shandong province is of great significance for the study of atmospheric mercury emissions in China.In order to understand the characteristics of atmospheric mercury pollution in coal-fired power plants in Shandong province,this study studied the atmospheric mercury of 25 coal-fired boilers in 9 power plants in Shandong province from 2015 to 2017,and selected coal-fired pollutant control facilities including electrostatic precipitator/fabric filters+selective non-catalytic reduction+wet flue gas desulfurization,electrostatic precipitator/fabric filters+selective catalytic reduction+wet flue gas desulfurization,fabric filters+selective non-catalytic reduction+wet flue gas desulfurization,electrostatic precipitator +selective catalytic reduction+wet flue gas desulfurization to conduct mercury emission tests.U.S.EPA 30B method was used for smoke sampling.Coal quality,desulfurized gypsum,bottom slag,fly ash,sulfur dioxide,nitrogen oxides were also monitored.According to the coal-fired emission and analysis shows:the emission concentration of atmospheric mercury in coal-fired power plants ranges from 0.25×10-4 mg/m3 to 0.11O×10-4 mg/m3,and the range of particulate matter varies from 0.3 to 0.9 mg/m3.The range of concentration varies from 3 to 89 mg/m3.The NOx range is from 0.39 to 94 mg/m3,and the removal efficiency is above 85%,which meets the emission standard for air pollutants in thermal power plants.The emission concentration of atmospheric mercury in coal-fired power plants is related to the types of boilers,air pollutant control measures,and installed capacity.The emission concentration of the coal-fired power plant whose boiler type is pulverized coal boiler is higher than that of a boiler whose type is circulating fluidized bed.Air pollution control measures complexity and size of the installed capacity is proportional to the atmospheric mercury emission concentration.According to the measured power plants and the basic situation of the coal-fired power plant in Shandong Province,combined with the coal-fired capacity and installed capacity of different coal-fired power plants,the emission factors A and B for coal-fired power plants in Shandong province were estimated,the emission factor A is 4.8×10-3 mg/kg,atmospheric mercury emission was 984.38 kg/a in Shandong province,and the emission factor of coal-fired power plants with emission factor B below 100 MW is 1.8×10-3 mg/kg,coal-fired power plants above 100 MW was 5.2×10-3 mg/kg,and atmospheric mercury emissions was 944.28 kg/a in Shandong province.Through the emission factors and the basic situation of coal-fired power plants in Shandong Province,the mercury emissions of various power plants were calculated,and the future mercury emissions are predicted.By the year 2020,the atmospheric mercury emissions in Shandong Province will be about 1.22-1.26 t/a,atmospheric mercury emissions of about 1.49-1.53 t/a by 2025.The measured emission factors and atmospheric mercury emissions are much lower than the pre-2010 statistics,indicating that since 2010,the improvement of pollutant control measures has resulted in the effective control of atmospheric mercury emissions from coal-fired power plants.