Determination of phenolic structures in low rank coals: elucidation of transformation processes of lignin at the early stage of coalification
Because lignin is considered to be a major precursor of coal vitrinite, chemical alteration studies of lignin structure are important for elucidating coalification processes as well as for understanding the chemical structure of vitrinite. Many investigators have attempted to elucidate the chemical processes in the coalification lignin. For example, Wayman et al have reported that a 100-million-year-old conifer consists of lignin-like material which is about one-third demethylated. Extensive cleavage of lignin ether linkages was also observed. Recently, based on /sup 13/C NMR study, Hatcher has concluded that the defunctionalization reactions of lignin-derived aromatic structures occur sequentially during coalification. A similar pathway has been suggested by Wilson. From a comparative NMR study of (/beta/-/sup 13/C) lignin and its coalified products, Botto has suggested that transformation of lignin is initiated by the heterolytic bond cleavage of labile /beta/-aryl ether groups. The present study continues the investigation of transformation processes of plant organic material to coal during early stages of coalification. To understand alteration of phenolic structures in lignin, and natural and synthetic coals have been characterized by using two-step depolymerization procedure of alkaline hydrolysis followed by silver oxide oxidation. In parallel experiments, lignin model compounds and a polymer have been transformed using thermal catalytic reaction conditions that mimic natural catagenetic metamorphism.
- Research Organization:
- Argonne National Lab., IL (USA)
- DOE Contract Number:
- W-31-109-ENG-38
- OSTI ID:
- 5932225
- Report Number(s):
- CONF-8809161-
- Journal Information:
- Prepr. Pap., Am. Chem. Soc., Div. Fuel Chem.; (United States), Vol. 33:3; Conference: Symposium on research with Argonne premium coal samples, Los Angeles, CA, USA, 25-30 Sep 1988
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
BITUMINOUS COAL
STRUCTURAL CHEMICAL ANALYSIS
BROWN COAL
LIGNIN
COALIFICATION
LIGNITE
SUBBITUMINOUS COAL
ALKALINE HYDROLYSIS
ALKYLATION
CARBOXYLIC ACIDS
CATAGENESIS
CHEMICAL BONDS
CLEAVAGE
COAL EXTRACTS
DEPOLYMERIZATION
GAS CHROMATOGRAPHY
HYDROGEN TRANSFER
MASS SPECTROSCOPY
OXIDATION
PHENOLS
SILVER OXIDES
AROMATICS
BLACK COAL
CARBOHYDRATES
CARBONACEOUS MATERIALS
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMATOGRAPHY
COAL
CRYSTAL STRUCTURE
DECOMPOSITION
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROLYSIS
HYDROXY COMPOUNDS
LYSIS
MATERIALS
MICROSTRUCTURE
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
POLYSACCHARIDES
SACCHARIDES
SEPARATION PROCESSES
SILVER COMPOUNDS
SOLVOLYSIS
SPECTROSCOPY
TRANSITION ELEMENT COMPOUNDS
010600* - Coal
Lignite
& Peat- Properties & Composition
011000 - Coal
Lignite
& Peat- Reserves
Geology
& Exploration