Alternative pathways for pyrolysis of cellulose
Pyrolysis of biomass involves heterogeneous substrates and complex reactions. The substrate may contain various amounts of cellulose, hemicelluloses, lignin, extractives and inorganics with different thermal properties. The reactions involve alternative pathways and consecutive series, which are affected by pyrolytic conditions including the time and temperature profile, ambient atmosphere and catalysis by inorganic materials. Consequently, composition, yield and rate of formation of the products are highly dependent on the employed substrate and pyrolytic condition. Pyrolysis at temperatures below 300/sup 0/C involves depolymerization, dehydration, rearrangement and formation of carboxyl and carbonyl groups, evolution of CO and CO/sub 2/, development of free radicals and condensation to char. At temperatures above 300/sup 0/C, these reactions are accompanied by the conversion of the glycosyl units to levoglucosan by transglycosylation. This reaction is preceded by the activation of the molecule, presumably through glass transition, which gives the required conformational flexibility. At still higher temperatures (above 500/sup 0/C), the glycosyl structure of the levoglucosan or cellulose rapidly breaks down to provide a variety of low molecular weight fission products, including hydrocarbons and hydrogen as well as CO, CO/sub 2/ and H/sub 2/O obtained at lower temperatures. The pyrolysis products could further react to alter the composition of the pyrolysate.
- Research Organization:
- Department of Chemistry, University of Montana, Missoula, Montana
- OSTI ID:
- 6205579
- Report Number(s):
- CONF-830814-
- Journal Information:
- Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States), Vol. 28:5; 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
BIOMASS
PYROLYSIS
CHEMICAL REACTION KINETICS
PYROLYSIS PRODUCTS
MOLECULAR STRUCTURE
CELLULOSE
PARAMETRIC ANALYSIS
TEMPERATURE EFFECTS
CARBOHYDRATES
CHEMICAL REACTIONS
DECOMPOSITION
ENERGY SOURCES
KINETICS
ORGANIC COMPOUNDS
POLYSACCHARIDES
REACTION KINETICS
RENEWABLE ENERGY SOURCES
SACCHARIDES
THERMOCHEMICAL PROCESSES
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