Determination of pyrolysis kinetic parameters of San Miguel (Texas) lignite. Final report. [650 to 800/sup 0/C; atmospheric pressure]
The thermal decomposition of lignite in the absence of oxygen (pyrolysis) is important as a part of processes for converting lignite to more desirable fuels or for recovery of energy from deep basin lignite. The pyrolysis reaction kinetics of San Miguel (Texas) lignite has been experimentally studied in the temperature range 650 to 800/sup 0/C at atmospheric pressure. Gas and tar produced were collected and measured, and weight change as a function of time was measured. Lignite decomposition into gas, tar, and char can be described by three parallel first order reactions. In the temperature range investigated, the rates of pyrolysis are controlled by intraparticle transport phenomena. A simplified kinetic-transport model was used to estimate the individual reaction rate constants and activation energies. The gas produced was found to consist primarily of carbon dioxide, carbon monoxide, and hydrogen, with some methane, ethane, ethylene, and a trace C/sub 3/ compounds. Sample temperature increases and theoretical calculations indicate that oxygen from the lignite structure may be oxidizing lignite or pyrolysis products. It is recommended that, after suitable equipment modifications, the investigation be extended to study combined oxidation and pyrolysis of lignite.
- Research Organization:
- Texas Tech Univ., Lubbock (USA). Dept. of Chemical Engineering
- OSTI ID:
- 5573837
- Report Number(s):
- TENRAC/EDF-098; ON: DE84900432
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
LIGNITE
PYROLYSIS
CHEMICAL REACTION KINETICS
PYROLYTIC GASES
CHEMICAL COMPOSITION
EXPERIMENTAL DATA
OXIDATION
TEMPERATURE DEPENDENCE
TEXAS
TIME DEPENDENCE
BROWN COAL
CARBONACEOUS MATERIALS
CHEMICAL REACTIONS
COAL
DATA
DECOMPOSITION
ENERGY SOURCES
FEDERAL REGION VI
FLUIDS
FOSSIL FUELS
FUELS
GASES
INFORMATION
KINETICS
MATERIALS
NORTH AMERICA
NUMERICAL DATA
PYROLYSIS PRODUCTS
REACTION KINETICS
THERMOCHEMICAL PROCESSES
USA
010406* - Coal & Coal Products- Pyrolysis & Cracking- (-1987)