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Title: TVA Clean Coal Technology IV project begins

Journal Article · · PETC Review (Pittsburgh Energy Technology Center); (United States)
OSTI ID:6324513

The Micronized Coal Reburning (MCR) demonstration project of the Tennessee Valley Authority (TVA) is one of nine projects selected for funding under round four of the Clean Coal Technology Program and one of six assigned to PETC for implementation. Awarded in July 1992, this project will be the first full-scale demonstration of the MCR technology, which controls nitrogen oxides (NO[sub x]) emissions from coal-fired steam generators. The TVA demonstration is expected to reduce NO[sub x] emissions by 50 to 60%. The MCR technology itself reduces NO[sub x] emissions to a level of 0.35 to 0.47 pounds per million Btu (0.15 to 0.20 kg/GJ). Micronized coal is very finely pulverized [80% less than 325 mesh (45 [mu])], may constitute up to 30% of the total fuel fired (depending on unit load), and is fired high in the furnace in a fuel-rich reburn zone above the top row of burners. Above the reburn zone, overfire air is injected into the burnout zone at high velocity for good mixing to ensure complete combustion. MCR technology reduces NO[sub x] emissions in the same manner as does natural gas reburning on coal-fired boilers. The entire furnace functions as a low-NO[sub x] burner with the existing burners being operated in a slightly oxidizing mode using accurate fuel/air control. The micronized fuel that is fired substoichiometricall in the reburn zone consumes oxygen very rapidly and converts NO[sub x] to molecular nitrogen. Above the reburn zone, high-velocity overfire air uniformly mixes with the substoichiometric furnace gas to complete combustion. Because it can be used in all standard pulverized coal units, MCR technology allows many facilities to reduce emissions and increase capacity with a minimum capital investment.

OSTI ID:
6324513
Journal Information:
PETC Review (Pittsburgh Energy Technology Center); (United States), Vol. 7
Country of Publication:
United States
Language:
English