Role of a carbon burnup cell in reducing SO/sub 2/ emissions from fluidized-bed coal combustion plants. [Evaluation of 4 limestone feed options]

Conference · Sat Jan 01 04:00:00 EST 1977

OSTI ID:5325845

Snyder, R. B.; Montagna, J. C.; Wilson, I.; Johnson, I.; Vogel, J.

To reduce the size and cost of an atmospheric-pressure fluidized-bed combustion (AFBC), a high superficial gas velocity (3 to 4.6 m/s) is required. However, high gas velocities cause high dust loadings (limestone and unburned coal) in the effluent gas stream. High gas velocities, therefore, produce low combustion efficiencies. Pope, Evans and Robbins (PER) have reported combustion efficiencies of approximately 85% at a fluidizing gas velocity of 3.8 m/s. To increase the overall combustion efficiency PER has incorporated into their process a carbon burnup cell (CBC) which operates at a higher temperature than the combustor and a lower fluidizing gas velocity (approximately 1100/sup 0/C, 1.8 m/s). Unburned coal dust removed from the combustor effluent stream by cyclones is injected into the CBC. Pope, Evans and Robbins estimate that the overall combustion efficiency can be increased to approximately 99%. The role of a carbon burnup cell in reducing limestone requirements to meet EPA SO/sub 2/ emission requirements for fluidized-bed coal combustor plants was investigated by evaluating laboratory scale experimental data. Four limestone feed options were analyzed. For Greer limestone the calculations predict that two of the options 2 and 4 would require approximately one-half as much limestone as the others. The reactivities of Tymochtee dolomite and Germany Valley limestone with SO/sub 2/ were compared with that of Greer at identical conditions. Tymochtee dolomite is more reactive than Greer. Germany Valley, being a high-calcium limestone, has poor reactivity and with any of the limestone feed options would require high Ca/S ratios to meet the EPA SO/sub 2/ standard. Again, two of the options were more favorable for Tymochtee and Germany Valley stones.

• Research Organization: Argonne National Lab., Ill. (USA)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 5325845
• Report Number(s): CONF-771015-12
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
014000* -- Coal
Lignite
& Peat-- Combustion
42 ENGINEERING
421000 -- Engineering-- Combustion Systems
AIR POLLUTION ABATEMENT
ALKALINE EARTH METAL COMPOUNDS
BURNERS
CARBON COMPOUNDS
CARBONACEOUS MATERIALS
CARBONATE ROCKS
CARBONATES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL
COMBUSTION
COMBUSTORS
DESIGN
DOLOMITE
EFFICIENCY
ENERGY SOURCES
FLUIDIZED-BED COMBUSTION
FLUIDIZED-BED COMBUSTORS
FOSSIL FUELS
FUELS
KINETICS
LIMESTONE
MAGNESIUM CARBONATES
MAGNESIUM COMPOUNDS
MINERALS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
POLLUTION ABATEMENT
REACTION KINETICS
RESERVOIR ROCK
ROCKS
SEDIMENTARY ROCKS
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES