Mitigation Potential of Mercury Emissions from Coal-Fired Power Plants in China

Abstract

With the rapid increase of coal consumption in China, the mercury emissions from coal-fired power plants have drawn global attention. In this study, a literature review on the mercury content of coal in China and the mercury removal efficiencies of particulate matter, SO2, and NOx control devices was conducted thoroughly. A probabilistic emission factor model was established to develop the mercury emission inventory for coal-fired power plants in China. The best estimate for total mercury emissions from coal-fired power plants in China was 96.5 tons (P50) in 2008, with the confidence interval from 57.3 tons (P10) to 183.0 tons (P90). The synergetic mercury removal benefit from the SO2 control measures during 2005–2008 was 33.9 tons. Two energy scenarios and three pollution control scenarios were developed to forecast the future trend of mercury emissions in China. The change of the energy structure and energy saving will play an important role in the mercury emission reduction in the next 2 decades. Under the current energy consumption pattern and air pollution control policies, the mercury emissions would increase to 196 tons in 2020. The installation of selective catalytic reduction (SCR) will result in 75 tons of mercury emission reduction during 2008–2020. Under the current energy consumption pattern and extended emission controls, the mercury emission in 2030 is 47% lower than that in 2020, because of the widespread application of SCR and the application of fabric filter (FF) and mercury-specific control technologies. Further reduction can be contributed by the enhancement of mercury-specific control technologies. Through the implementation of energy policies with accelerated control technologies, the mercury emission in 2030 can be decreased by 71% from the level of 2008, which shows the significant mitigation potential of mercury emissions from coal-fired power plants in China in the future.