Structural characterization of coal: lignin-like polymers in coals
Although lignins are major constitutents of vascular plants from which coals are derived, their roles in the coalification process have not been defined. On the basis of chemical and biological degradations, lignins are considered to be polymers of propylphenyl compounds, coniferyl alcohol and related alcohols. Because of their great abundance, high resistance to biological degradation and characteristic occurrence in lplants, isolation of coal degradation products related to these lignin compounds should shed some light on the roles, if any, played by lignins during coalification and in the final structure of coals. To date such studies have had only limited success. Although fulvic and humic acids have been degraded successfully with alkaline solutions to produce lignin-related phenols, this method has not proved to be useful for coals. Many oxidative degradations have also been carried out to break coal down into simpler species; however, isolation and identification of phenols such as p-hydroxybenzene derivatives, vanillic and syringic groups, which are characteristic lignin oxidation products, have not been definitely confirmed yet. In general, commonly used oxidants destroy phenolic rings or give complex products. Some of the oxidants such as nitrobenzene produce reaction by-products that may interfere with the analysis of the oxidation products. To obtain lignin oxidation products from coals, we resorted to the alkaline cupric oxide oxidation method which has been successfully applied to analysis of lignins in plants, fulvic and humic acids, and land-derived marine sediments.
- Research Organization:
- Argonne National Lab., IL
- OSTI ID:
- 6085741
- Report Number(s):
- CONF-790415-P2
- Journal Information:
- Am. Chem. Soc., Div. Fuel Chem., Prepr.; (United States), Journal Name: Am. Chem. Soc., Div. Fuel Chem., Prepr.; (United States) Vol. 24:1; ISSN ACFPA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Structural characteristics of vitrinites
Oxidative degradation studies and modern concepts of the formation and transformation of organic constituents of coals and sedimentary rocks
Related Subjects
010600* -- Coal
Lignite
& Peat-- Properties & Composition
BIODEGRADATION
CARBOHYDRATES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMATOGRAPHY
COAL
COPPER COMPOUNDS
COPPER OXIDES
DECOMPOSITION
ENERGY SOURCES
FOSSIL FUELS
FUELS
GAS CHROMATOGRAPHY
LIGNIN
MASS SPECTROSCOPY
ORGANIC COMPOUNDS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
POLYSACCHARIDES
SACCHARIDES
SEPARATION PROCESSES
SPECTROSCOPY
STRUCTURAL CHEMICAL ANALYSIS
TRANSITION ELEMENT COMPOUNDS