2018 Volume 97 Issue 11 Pages 342-347
To evaluate mercury partitioning in a coal-fired power plant and to investigate the influence of the configuration of gas treatment facilities on mercury emission, data sets of mercury concentration in coal, coal combustion residues, wastewater, and stack gases were collected from 44 coal-fired power plants in Japan from 2001 to 2014. The mean mercury concentration in coal, measured from 1224 samples, was 0.039 mg/kg, while the mean emission rate, measured from 259 samples, was 3.63 μg/kWh. The total annual mercury emission from coalfired power plants in Japan, which was calculated using the mean emission rate, was 1.0 t. The mercury removal efficiency was found to be improved by decreasing the electrostatic precipitator (ESP) operation temperature and by implementing selective catalytic reduction (SCR). The combination of SCR, advanced low-temperature ESP, and flue gas desulfurization (FGD) showed a high mercury removal efficiency of 87.4% on average.
