Mercury Sampling and Measurement in Coal-Fired Power Plants - Mercury Emission and its Control in Chinese Coal-Fired Power Plants - page 19

was added, the proportion of Hg 0 was higher than that of Hg 2+ .
According to the test data, the emission factor of ESP mercury in coal-fired
power plants was approximately 0.875 on average. The mercury removal efficiency
of ESP in power plants was associated with coal varieties, ESP structure, and other
factors. In addition, ESP mainly removed Hg p .
The role of mercury removal was played by WFGD through washing, especially
for water-soluble Hg 2+ . The dissolution effect of WFGD limestone and slurry be-
came more prominent. It could be estimated in this study that the emission factor of
WFGD demercuration was 0.252.
Test data showed that SCR transformed most of the gaseous Hg 0 into the ga-
seous Hg 2+ , presenting a conversion efficiency of about 85%. At high temperature,
Hg (g) effectively reacted with the oxidation catalyst. The degree of oxidation was
related to coal types, gas composition, catalyst nature, temperature, and so on.
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