Multi-method Mercury Specification From Lignite-fired Power Plants

摘要

Mercury concentration and speciation partitioning, including total mercury, elemental mercury and oxidized mercury from a lignite-fired power plant under different operating conditions, was studied by Ontario hydro method (OHM), two kinds of continuous mercury monitors (semi-continuous emission monitor (SCEM) and continuous mercury monitor (CMM)), and the sorbent trap method. The effects of boiler load, fuel blending ratio, electrostatic pre-cipitator, flue gas desulphurization, flue gas bypassing the FGD ratio, and mercury measuring methods on mercury emission were analyzed. The results indicated that mercury data from OHM, SCEM and CMM presented a good consistency throughout the entire testing period within ±20% acceptable range; however, the results from Appendix K provided bigger discrepancies than the results of OHM and SCEM due to the interferences of higher selenium content in the flue gas. The particulate-bound mercury removal efficiencies of ESP were determined to be 16-35%. The percentages of elemental mercury emitted from two lignite-fired power plants were in the higher ranges of 43.9-74.2%.