Observations on the combustion behavior of coal water fuels and coal water fuels impregnated with calcium magnesium acetate

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Combustion and Flame; (United States)

DOI:https://doi.org/10.1016/0010-2180(93)90084-G· OSTI ID:6491178

Atal, A; Levendis, Y A ^[1]

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1. Northeastern Univ., Boston, MA (United States)

Combustion studies of single free-falling coal-water fuel (CWF) droplets were conducted in a drop-tube laminar-flow furnace at high heating rates. Most experiments were conducted with predried CWF agglomerates consisting of micronized (3.5 [mu]m mean size) and beneficiated bituminous coal. Agglomerates of known initial size, in the range of 100-600 [mu]m, were burned in air or pure oxygen at furnace temperatures between 1300 and 1500 K. Combustion of CWF agglomerates impregnated with calcium magnesium acetate (CMA), which is being considered as a sulfur capture agent, was also examined under the same conditions. Observations on the devolatilization and char combustion behavior of CWF agglomerates, formed after the evaporation of water, were conducted using pyrometric and cinematographic techniques. The char combustion is the most prominent since it accounts for 75%-85% of the burnout time. The volatile combustion phase is also important because of the resulting high-temperature radiant flames. Overall burnout times were between 150 and 600 ms, for the range of agglomerate sizes tested. Char combustion for most agglomerates was controlled by boundary layer diffusion of oxygen. The swelling behavior of the agglomerates was studied and swelling factors in the neighborhood of 1.12 were determined. Although the bituminous CWF, was found to swell and form cenospheric structures during heatup and devolatilization, the addition of CMA catalyst inhibited swelling of the agglomerates. However, the chars containing CMA exhibited occasional splitting or fragmentation during the volatile combustion stage.

• OSTI ID: 6491178
• Journal Information: Combustion and Flame; (United States), Journal Name: Combustion and Flame; (United States) Vol. 93:1-2; ISSN CBFMAO; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
014000* -- Coal
Lignite
& Peat-- Combustion
ACETATES
ADSORBENTS
AGGLOMERATION
AIR POLLUTION ABATEMENT
ALKALINE EARTH METAL COMPOUNDS
BITUMINOUS COAL
BLACK COAL
CALCIUM COMPOUNDS
CARBONACEOUS MATERIALS
CARBOXYLIC ACID SALTS
CHALCOGENIDES
CHARS
CHEMICAL REACTION KINETICS
COAL
COMBUSTION KINETICS
DEVOLATILIZATION
DISPERSIONS
DROPLETS
ENERGY SOURCES
FLUID FLOW
FOSSIL FUELS
FRAGMENTATION
FUEL SLURRIES
FUELS
HEATING RATE
HYDROGEN COMPOUNDS
IMPREGNATION
KINETICS
LAMINAR FLOW
MAGNESIUM COMPOUNDS
MATERIALS
MEASURING METHODS
MIXTURES
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
PARTICLES
PERFORMANCE TESTING
POLLUTION ABATEMENT
PYROLYSIS PRODUCTS
REACTION KINETICS
SIZE
SLURRIES
SORBENT INJECTION PROCESSES
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES
SUSPENSIONS
SWELLING
TESTING
WATER