Experimental investigation of the initial stages of pulverized bituminous coal combustion

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:6969088

Tsai, C Y

The effect of maceral composition and particle size on the weight loss and structural changes of pulverized coal particles during combustion has been investigated. A comparison of the results between pyrolysis and combustion was used to examine the physical and chemical changes of the coal particles in the initial stages of a pulverized coal flame. A numerical investigation of the time-temperature history of coal particles was also conducted to elucidate their thermal behavior. The pyrolysis and combustion experiments were conducted in an entrained-flow reactor at temperatures from 1000 K to 1200 K in N/sub 2/ and air atmospheres. Variations in maceral composition were achieved by size and gravity separations of a pulverized bituminous coal. The order of decreasing weight loss by pyrolysis of samples with various maceral compositions was the same as that of the proximate volatile matter; that is, liptinite rich > vitrinite rich > inertinite rich. However, for combustion this trend did not always apply. Examination of the coal/char structural transformations suggested that the vitrinite in the bituminous coal softened earlier and developed larger cenospheres than the other macerals. The development of microporosity occurred predominately after the resolidification of the swelled char particles and was dominated by the extent of secondary volatiles evolution. The type of macerals originally in the coal did not significantly affect the final microporosity developed. Conversely, the presence of liptinite tended to enhance the thermoplasticity and formation of thin-walled cenospheres with a high extent of anisotropy; a high concentration of inertinite led to the formation of isotropic lacy or thick walled censopheres.

• Research Organization: Pennsylvania State Univ., University Park (USA)
• OSTI ID: 6969088
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010409 -- Coal
Lignite
& Peat-- Pyrolysis & Carbonization-- (1987-)
014000* -- Coal
Lignite
& Peat-- Combustion
AIR
BITUMINOUS COAL
BLACK COAL
CARBONACEOUS MATERIALS
CHARS
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL
COMBUSTION KINETICS
COMPARATIVE EVALUATIONS
DECOMPOSITION
ELEMENTS
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUELS
GASES
KINETICS
MACERALS
MATERIALS
MICROSPHERES
MORPHOLOGICAL CHANGES
NITROGEN
NONMETALS
PARTICLE SIZE
POROSITY
PULVERIZED FUELS
PYROLYSIS
PYROLYSIS PRODUCTS
REACTION KINETICS
SIZE
TEMPERATURE DEPENDENCE
THERMOCHEMICAL PROCESSES
TIME DEPENDENCE