Combustion reactivity of low rank coal chars
For many years the CSIRO has been involved in studies on the combustion kinetics of coal chars and related materials. Early work included studies on a char produced from a Victorian brown coal. More recently, the combustion kinetics of chars produced during the flash pyrolysis of sub-bituminous coals have been determined. Data are given for the combustion reactivities of four flash pyrolysis chars. Their reactivities are compared with the results for chars produced from low and high rank coals, and petroleum coke. Reactivity is expressed as the rate of combustion of carbon per unit external surface area of the particle, with due correction being made for the effect of the mass transfer of oxygen to the particle. It has been shown that the reactivities to oxygen of chars produced from Millmerran sub-bituminous coal decrease with increasing pyrolysis temperature but are similar in magnitude to the reactivities of chars derived from a brown and a bituminous coal and to the reactivities of anthracites and semi-anthracites. However, Wandoan char, also of sub-bituminous origin, exhibits about twice the reactivity of Millmerran char and about ten times the reactivity of petroleum coke. On the basis of observed activation energy values, particle size and particle density behaviour it is concluded that the combustion rates of Millmerran and Wandoan chars are controlled by the combined effects of pore diffusion and chemical reaction.
- Research Organization:
- CSIRO Division of Fossil Fuels, North Ryde, NSW
- OSTI ID:
- 7089603
- Report Number(s):
- CONF-830814-
- Journal Information:
- Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States), Vol. 28:4; Conference: 186. national meeting of the American Chemical Society, Washington, DC, USA, 28 Aug 1983
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CHARS
ACTIVATION ENERGY
COMBUSTION KINETICS
COKE
COMBUSTION PRODUCTS
COMPARATIVE EVALUATIONS
DENSITY
FLASH HYDROPYROLYSIS PROCESS
MICROSTRUCTURE
PARTICLE SIZE
POROSITY
SUBBITUMINOUS COAL
TECHNOLOGY ASSESSMENT
CARBONACEOUS MATERIALS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
COAL
COAL GASIFICATION
COAL LIQUEFACTION
CRYSTAL STRUCTURE
DECOMPOSITION
ENERGY
ENERGY SOURCES
FOSSIL FUELS
FUELS
GASIFICATION
KINETICS
LIQUEFACTION
MATERIALS
PHYSICAL PROPERTIES
PYROLYSIS
PYROLYSIS PRODUCTS
REACTION KINETICS
SIZE
THERMOCHEMICAL PROCESSES
010600* - Coal
Lignite
& Peat- Properties & Composition