Experimental factors affecting coal devolatilization time in fluidized bed combustion

Journal Article · Tue Dec 31 23:00:00 EST 1991 · Fuel Science and Technology International; (United States)

DOI:https://doi.org/10.1080/08843759208915997· OSTI ID:5652835

Stubington, J F; Chui, T Y.S.; Saisithidej, S ^[1]

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1. Dept. of Fuel Technology, School of Chemical Engineering and Industrial Chemistry, Univ. of NSW, P.O. Box 1 Kensington, NSW 2033 (AU)

Coal particle devolatilization times were determined by analysis of the flue gas from an air-fluidized bed at 850{degrees} C, when single coal particles were injected. The CO{sub 2} concentration versus time profile was corrected for gas flow and dispersion in the sampling line and analyzer, and the devolatilization time was measured as the time from particle injection to the time corresponding to the minimum CO{sub 2} concentration separating volatiles and char combustion. No differences in devolatilization time were observed for the three Australian bituminous coals studied, and similar times were measured for both spherical and irregularly-shaped particles, provided the equivalent-mass definition of diameter was used. Comparison with literature data showed that this method for measuring coal particle devolatilization time gave similar values to the visual flame extinction time and greater values than visual flame period. From a critical analysis of the literature, it was deducted that batch size (i.e. number of particles in each batch) could affect the measured devolatilization time, that no such effect was present for some of the data for small numbers of large diameter particles in large diameter beds. In this paper the effects of temperature, oxygen concentration, coal moisture content and fragmentation on devolatilization time are discussed, and recommendations for further work are proposed.

• OSTI ID: 5652835
• Journal Information: Fuel Science and Technology International; (United States), Journal Name: Fuel Science and Technology International; (United States) Vol. 10:3; ISSN FSCTE; ISSN 0884-3759
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404 -- Coal
Lignite
& Peat-- Gasification
010600 -- Coal
Lignite
& Peat-- Properties & Composition
014000* -- Coal
Lignite
& Peat-- Combustion
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHARS
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
COAL
COAL FINES
COMBUSTION
DEVOLATILIZATION
ENERGY SOURCES
FLUE GAS
FLUID FLOW
FLUIDIZED-BED COMBUSTION
FOSSIL FUELS
FUELS
GAS FLOW
GASEOUS WASTES
MATERIALS
MATTER
MOISTURE
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PARAMETRIC ANALYSIS
PARTICLE SIZE
PARTICLES
PYROLYSIS PRODUCTS
SIZE
TEMPERATURE EFFECTS
THERMOCHEMICAL PROCESSES
VOLATILE MATTER
WASTES