Mercury emission trend influenced by stringent air pollutants regulation for coal-fired power plants in Korea

摘要

Regulatory control of mercury emission from anthropogenic sources has become a global concern in the recent past. Coal-fired power plants are one of the largest sources of anthropogenic mercury emission into the atmosphere. This paper summarizes the current reducing trend of mercury emission as co-beneficial effect by more stringent regulation changes to control primary air pollutants with introducing test results from the commercial coal-fired facilities and suggesting a guideline for future regulatory development in Korea. On average, mercury emission concentrations ranged 16.3-2.7 μg Sm~(-3), 2.4-1.1 μg Sm~(-3), 3.1-0.7 μg Sm~(-3) from anthracite coal-fired power plants equipped with electrostatic precipitator (ESP), bituminous coal-fired power plants with ESP + flue gas desulphurization (FGD) and bituminous coal-fired power plants with selective catalytic reactor (SCR) + cold side (CS) - ESP + wet FGD, respectively. Among the existing air pollution control devices, the best configuration for mercury removal in coal-fired power plants was SCR + CS - ESP + wet FCD, which were installed due to the stringent regulation changes to control primary air pollutants emission such as SO_2, NOx and dust. It was estimated that uncontrolled and controlled mercury emission from coal-fired power plants as 10.3 ton yr~(-1) and 3.2 ton yr~(-1) respectively. After the installation of ESP, FGD and SCR system, following the enforcement of the stringent regulation, 7.1 ton yr~(-1) of mercury emission has been reduced (nearly 69%) from coal-fired power plants as a co-benefit control. Based on the overall study, a sample guideline including emission limits were suggested which will be applied to develop a countermeasure for controlling mercury emission from coal-fired power plants.