Pyrolysis and gasification of coal at high temperatures

Technical Report · Mon Jan 01 04:00:00 EST 1990

OSTI ID:6035255

Zygourakis, K

The systematic investigation on the effects of pyrolysis conditions and char macropore structure on char reactivity continued. During the past quarter, we concentrated our efforts on studying the reactivity of chars devolatilized in reactive atmospheres and under pyrolysis conditions encountered in mild gasification processes. Pyrolysis and gasification experiments were performed consecutively in our TGA/VMI reactor. After pyrolyzing the coal particles to a final heat treatment temperature of 500 {degree}C, the char reactivity patterns were measured at three temperatures (420, 450 and 500 {degree}C). The lower heat treatment temperatures employed for these experiments (500 {degree}C or close to mild gasification conditions) resulted in more reactive chars. We compared the reactivities of chars pyrolyzed in inert (N{sub 2}) and reactive (O{sub 2}/N{sub 2}) atmospheres in both the kinetic and the diffusion limited regime. Significant differences in the reactivity of these two groups of chars were found in the diffusion limited regime. Finally, we used the microscopy of our thermogravimetric reactor to monitor the structure transformations occurring during pyrolysis with oxygen. Pyrolysis experiments were videotaped and particle swelling, particle ignitions and fragmentation were determined and analyzed using digitized images from these experiments. 5 figs., 1 tab.

• Research Organization: Rice Univ., Houston, TX (USA). Dept. of Chemical Engineering
• Sponsoring Organization: DOE; USDOE, Washington, DC (USA)
• DOE Contract Number: FG22-87PC79930
• OSTI ID: 6035255
• Report Number(s): DOE/PC/79930-T5; ON: DE91008957
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404* -- Coal
Lignite
& Peat-- Gasification
010409 -- Coal
Lignite
& Peat-- Pyrolysis & Carbonization-- (1987-)
BITUMINOUS COAL
BLACK COAL
CARBONACEOUS MATERIALS
CHARS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL
COAL GASIFICATION
COMBUSTION
DECOMPOSITION
DOCUMENT TYPES
ELEMENTS
ENERGY SOURCES
FOSSIL FUELS
FRAGMENTATION
FUELS
GASIFICATION
IGNITION
KINETICS
MATERIALS
MICROSCOPY
NITROGEN
NONMETALS
OXIDATION
OXYGEN
PARTICLES
POROSITY
PROGRESS REPORT
PYROLYSIS
PYROLYSIS PRODUCTS
REACTION KINETICS
SWELLING
TEMPERATURE EFFECTS
THERMOCHEMICAL PROCESSES