Flue gas Hg measurements from coal-fired boilers equipped with wet scrubbers
The US EPA has instituted an Information Collection Request{at} to obtain information regarding mercury (Hg) emissions from coal-fired utility boilers. EPA is in the process of collecting information regarding the Hg concentrations of the coals fired in over 1,000 utility boilers, and flue gas Hg emission and speciation data at {approximately}100 utility boilers. EPA will review these data to determine if Hg emission reduction from the utility industry is necessary. Presently, there is no proven mercury-control technology for this source category. Hg removal by carbon injection has been tested at the pilot scale level. The mercury removal costs for this technology is estimated to be $10 million to $40 million per ton of Hg removed. CONSOL Inc. completed flue gas Hg measurements at five coal-fired boilers and one industrial boiler equipped with conventional wet scrubbers for SO{sub 2} control. Based on a minimum of triplicate scrubber inlet and outlet measurements at each site, the Hg removal by the scrubber systems was 54%, with a standard deviation of 7%. Accounting for the Hg collected on the ash particles, the total plant Hg removal was 67 {+-} 6%. These data show that utility boilers equipped with ESP scrubber combinations are removing two-thirds of the Hg in the as-fired coal at no added cost. The Hg speciation data showed that 80% to 95% of the oxidized Hg fraction, as determined from the Ontario Hydro method, was removed by the scrubber. The average Hg material balance closure at the six test sites was 103 {+-} 8%. The Hg removed from the flue gas was accounted for in the scrubber solids. Standard leachate testing conducted on fixated and unfixated scrubber sludge from one test site showed no Hg leaching. Volatility testing conducted by heating this sludge to 140 F for 11 weeks showed no loss of Hg.
- Research Organization:
- CONSOL Inc., Library, PA (US)
- OSTI ID:
- 20002205
- Report Number(s):
- CONF-990608-; TRN: IM200002%%205
- Resource Relation:
- Conference: Air and Waste 92nd Annual Meeting and Exhibition, St. Louis, MO (US), 06/20/1999--06/24/1999; Other Information: 1 CD-ROM. Operating Systems: Windows 3.1, '95, '98 and NT; Macintosh; and UNIX; PBD: 1999; Related Information: In: Air and Waste 92nd annual meeting and exhibition proceedings, [9500] pages.
- Country of Publication:
- United States
- Language:
- English
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