Potential Analysis of Synergetic Mercury Removal from Coal-Fired Flue Gas on Purification Equipment after Retrofitting of Ultra-low Emission

doi:10.11930/j.issn.1004-9649.201707018

Abstract

Abstract: The ultra-low emissions retrofitting improves the flue gas purification equipment in the coal-fired power plant greatly in terms of the equipment capacity and quality. In order to provide the basis for decision-making on the control of mercury emission, the synergistic mercury removal efficiency of the purification equipment is analyzed. The results show that the SCR system retrofitting can increase the oxidation efficiency of Hg⁰ and promote the mercury removal efficiency of the dust removal equipment and the desulfurization equipment. The mercury removal effect of the low-temperature electrostatic precipitator and the electrical fabric filter can reach up to 40%. The desulfurization equipment with a high efficient demister can remove mercury in a synergistic manner with an efficiency of 96%. However, due to the low Hg²⁺ concentration at the outlet of the dust collector as well as the low dust concentration and the small particle size, the influence on mercury removal efficiency in flue gas is limited from the single tower retrofitting and the wet electrostatic precipitator in the desulphurization system. It is also possible that the mercury emission concentration at the outlet of the desulphurization system is slightly higher than that at the inlet after the single tower retrofitting.

Key words: coal-fired power plant, flue gas, mercury, ultra-low emissions, purification equipment, SCR, low-temperature electrostatic precipitator, electrical fabric filter, high efficient demister, WESP

CLC Number:

CHEN Kunyang, GUO Tingting, WANG Haigang, HU Dong. Potential Analysis of Synergetic Mercury Removal from Coal-Fired Flue Gas on Purification Equipment after Retrofitting of Ultra-low Emission[J]. Electric Power, 2018, 51(6): 160-165.

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URL: https://www.electricpower.com.cn/EN/10.11930/j.issn.1004-9649.201707018

https://www.electricpower.com.cn/EN/Y2018/V51/I6/160

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