Start Over

Field test of SO 3 removal in ultra-low emission coal-fired power plants.

Authors :: Zhang Y
Zheng C
Hu F
Zhao H
Liu S
Yang Z
Zhu Y
Gao X
Source :: Environmental science and pollution research international [Environ Sci Pollut Res Int] 2020 Feb; Vol. 27 (5), pp. 4746-4755. Date of Electronic Publication: 2019 Dec 16.
Publication Year :: 2020
Abstract: Under the extensive implementation of ultra-low emission (ULE) facilities in coal-fired power plants of China, sulfur trioxide (SO <subscript>3</subscript> ) has received increasing attention due to its impact on human health and operation safety of power plants. However, systematic research and evaluation for controlling SO <subscript>3</subscript> emission in various ULE facilities are still lacking. Here, a systematic study was conducted based on 378 in situ performance evaluation tests carried out in 148 coal-fired power plants. The results illustrate that the SO <subscript>2</subscript> /SO <subscript>3</subscript> conversion rate of the selective catalytic reduction devices can be controlled within 1% before and after ULE retrofit. Also, the synergistic removal efficiency of SO <subscript>3</subscript> in the low-low-temperature electrostatic precipitator and the wet electrostatic precipitator can be higher than 70%. The removal efficiency of SO <subscript>3</subscript> in the wet limestone-gypsum flue gas desulfurization scrubber is 33-64% before ULE and 31-81% after, and the average efficiency of the double scrubbers is 8.7% higher than that of the single scrubber. Due to the different SO <subscript>3</subscript> removing abilities of various technologies, the overall efficiency of SO <subscript>3</subscript> removal is in the range between 27 and 95% adopting different ULE technical routes. Average concentration of SO <subscript>3</subscript> emission can be decreased by 51.8% after ULE application.