The Study On Emission Standards For Coal Fired Power Plants Of Mercury And Simulation Of Their Environmental Impact

Mercury can cause neurotoxic effect and accumulatein living organisms. Pollution caused by Hg in the atmosphere has aroused attentionworldwide. As one of the countries emitting large amount Hg, China has become more and more important to fulfill the international responsibilities and obligations. Coal is one of the main sources of atmospheric Hg in China, and coal-fired power plants consume almost50%of total coal consumption, which will ramp up sharply in the coming years as the electric power industry develops. The emission limits of mercury and its compounds of coal-powered plants were established in the Emission Standard of Air Pollutants for Thermal Power Plants(GB13223-2011), which hasgreat significance for mercury emission control.Based on the Emission Standard of Air Pollutants for Thermal Power Plants(GB13223-2011), five kinds of scenarios were simulated. According to the national economic development and the consumption of coal, we calculated the growth of thermal power unit in every region for nearly10years, and extrapolated the capacity of thermal power unit in2015and2020, then set up the2010,2015,2020years’ emission inventory. CMAQ-Hg model wasused to simulate the environmental impact of atmospheric mercury of five scenarios. The mercury emission reduction percentage was evaluated. The future mercury emission controlstrategy was discussed.The results showed that it could effectively reduce the atmosphere Hg with the technology of synergetic control (SCR+SP/PP+WFGD) after the GB13223-2011Standard was put into practice. The Hg emission would be92.7t in2015and96.7t in2020, which were19.5%and13.6%off compared to2010, and39.2%and45.8%off to2015and2020before the new standardwasinto effect. The Hg emission in the areaswith Hg concentration higher than1.0ng/m3would be reduced by25.2%in2015and20.6%in2020compared with the year of2010, andreduced by40.8%and39.9%to2015and2020before the new standard. The total settlement of Hg would run upto41.59t in2015and44.67t in2020, which was19.5%and13.6%off compared to2010, and39.2%and45.8%off to2015and2020before the new standard.We can conclude that the regional air quality will be improvedsince the mercury emission reduction was obvious after the new emission standard took effect.