Combustion kinetics of high-ash coals in fluidized beds

Journal Article · Wed Jan 31 23:00:00 EST 1990 · Combustion and Flame; (USA)

DOI:https://doi.org/10.1016/0010-2180(90)90041-O· OSTI ID:6895154

Durao, D F.G.; Ferraro, P ^[1]; Gulyurtlu, I ^[2]; Heitor, M V ^[1]

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1. Dept. of Mechanical Engineering, Instituto Superior Tecnico, Lisbon (PT)
2. Dept. of Conventional Energies, Laboratorio Nacional Eng. Tec. Industrial, Lisbon (PT)

Burnout times of high-ash coals in a fluidized bed were determined for coal particle sizes ranging from 0.125 to 4 mm, over a temperature range of 973--1173 K and fluidization velocities varying from 3.7{ital U}{sub mf} to 6.2{ital U}{sub mf}. The results show that the mode with which anthracite particles burn resembles that of a shrinking core of unchanged initial particle diameter. With these anthracites it was observed that diffusion through an ash layer becomes more important as the burning core diameter decreases with time. It can also be concluded that the combustion of the anthracites appears to be most influenced by the bed temperature and particle size. The combustion of particles at 1173 K is primarily controlled by diffusion of oxygen to the surface of the particles and through the ash layer. The influence of chemical kinetics on the combustion process increases considerably with decreasing bed temperature and is the dominant resistance below 1073 K for all the particle sizes tested.

• OSTI ID: 6895154
• Journal Information: Combustion and Flame; (USA), Journal Name: Combustion and Flame; (USA) Vol. 79:2; ISSN CBFMA; ISSN 0010-2180
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010600 -- Coal
Lignite
& Peat-- Properties & Composition
014000* -- Coal
Lignite
& Peat-- Combustion
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400800 -- Combustion
Pyrolysis
& High-Temperature Chemistry
42 ENGINEERING
421000 -- Engineering-- Combustion Systems
ASH CONTENT
CARBONACEOUS MATERIALS
CHEMICAL REACTION KINETICS
COAL
COMBUSTION KINETICS
COMBUSTORS
DIFFUSION
ELEMENTS
ENERGY SOURCES
FLUIDIZED-BED COMBUSTORS
FOSSIL FUELS
FUELS
KINETICS
MATERIALS
NONMETALS
OXYGEN
PARTICLE SIZE
REACTION KINETICS
SIZE