Fine particulate matter emission and size distribution characteristics in an ultra-low emission power plant

Abstract The pollution emitted by power plants is a continuing environmental problem around the world. Recently, China has proposed new regulations limiting emissions. The new regulations include a reduction in particulate matters (PM) emission to less than 5 mg/Nm 3 to reach Ultra-Low Emission (ULE) standards. This research examines the PM emission from a ULE power plant. The power plant was equipped with a low-temperature economizer, a wet electrostatic precipitator (WESP), a retrofitted electrostatic precipitator (ESP) and a flue gas desulfurization (FGD) system. The PM 10 , PM 2.5 and PM 1 emissions were 0.36 mg/m 3 , 0.36 mg/m 3  and 0.09 mg/m 3 , respectively. The capturing efficiencies of the retrofitted ESP and WESP were over 98.7% and 80.5%, respectively. The FGD did not significantly capture PM 2.5  and PM 1 . The PM collected from the Electrical Low Pressure Impactor (ELPI+) was analyzed using scanning electron microscope/energy dispersive spectrometer (SEM/EDS). The SEM/EDS data showed small limestone/gypsum particles. These particles probably entered the flue gas from the FGD. This research shows that WESP can effectively capture PM greater than 0.3μm and particles of limestone and gypsum.