Rate of reaction of oxygen and steam with char/coke. [5 refs. ; 400--600/sup 0/C]

Conference · Wed Jan 01 04:00:00 EST 1975 · Am. Chem. Soc., Div. Fuel Chem., Prepr.; (United States)

OSTI ID:7340817

Nandi, S P; Lo, R; Fischer, J

Three subbituminous coals and one MVB coal were pyrolyzed in a nitrogen atmosphere to 900/sup 0/C. The pyrolyzed residues were reacted with oxygen and steam. The rate of reaction was followed gravimetrically using a thermobalance. The particle size of the sample was (40 x 80) mesh and the bed height was about one particle diameter. Reaction with air was followed at four temperatures in the range 400 to 600/sup 0/C. After an induction period the weight loss was linear with time for an extended burn-off range. The rate of reaction was obtained from the linear region and was found to increase with a decrease in the rank of the parent coal. The temperature coefficient of the rate was low. The slope of the Arrhenius plots decreased with increasing temperature and attained a value of approximately 15 Kcal/mole for chars in the temperature interval between 500 to 550/sup 0/C. A similar decrease in the slope of the plot for the coke was observed at approximately 50/sup 0/C higher temperature. Reaction with 2.3 vol percent of steam was followed with the same samples in the temperature range 800 to 900/sup 0/C. Induction periods for the reaction with steam were very short or nonexistent. The reaction rate was zero order with respect to carbon for an extended burn-off region. The temperature coefficient of the rate (approximately 30 Kcal/mole for the chars) tends to indicate that the rate was pore-diffusion-controlled and suggests that a possible catalytic effect due to the mineral content of the chars may have been operative.

• Research Organization: Argonne National Lab., IL
• OSTI ID: 7340817
• Conference Information: Journal Name: Am. Chem. Soc., Div. Fuel Chem., Prepr.; (United States) Journal Volume: 20:3
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010403 -- Coal & Coal Products-- Hydrogenation-- (-1987)
010404* -- Coal
Lignite
& Peat-- Gasification
ATMOSPHERES
CARBONACEOUS MATERIALS
CATALYSIS
CHARS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL
COAL GASIFICATION
COAL RANK
COKE
CONTROLLED ATMOSPHERES
CRYOGENIC FLUIDS
DECOMPOSITION
ELEMENTS
ENERGY SOURCES
FLUIDS
FOSSIL FUELS
FUELS
GASIFICATION
KINETICS
NITROGEN
NONMETALS
OXYGEN
PARTICLE SIZE
PYROLYSIS
REACTION KINETICS
SIZE
STEAM
SUBBITUMINOUS COAL