Chemistry of lignite liquefaction. Quarterly report for the period January-March, 1982
Asphaltene and preasphaltene components of samples of solvent-refined lignites prepared at 400, 460 and 480/sup 0/C have been isolated by solvent fractionation. The composition of the asphaltenes and preasphaltenes have been analyzed for their number average molecular weight distribution, acid components, oxygen functionality and aromatic structure. Three significant differences between preasphaltenes and asphaltenes were noted. First, the molecular weight distribution maximizes 200 to 300 g-mol higher for the preasphaltenes compared to the asphaltenes. Second, the asphaltenes contained a higher degree of condensed aromatic systems than the corresponding preasphaltenes. Third, the acid oxygen (hydroxyl) components of the two categories are nearly the same, but the other oxygen functionality is more like diaryl ethers for asphaltenes while the preasphaltenes contain more furan type oxygen. Increased reaction temperature has the effect of removing oxygen (mainly ethers) and forming more condensed aromatic systems. Sodium, HMPA, BBr/sub 3/, (CH/sub 3/)/sub 3/SiI have been developed as ether cleavage reagents and applied to preasphaltene and asphaltenes. Experimental work completed on the model compounds: PhSPh, PhN(CH/sub 3/)/sub 2/, PhOPh, PhCH/sub 2/Ph, PhCH/sub 2/CH/sub 2/Ph, lignin and sexiphenyl suggested H/sub 2/-H/sub 2/S and CO-H/sub 2/O-H/sub 2/S to be effective reducing gases for coals at liquefaction temperatures. This prediction has now been verified. Lignite gives extraordinary yields of oil at the expense of gases and unconverted coal. The mechanisms of H/sub 2/S action are described.
- Research Organization:
- North Dakota Univ., Grand Forks (USA)
- DOE Contract Number:
- AB18-78FC02101
- OSTI ID:
- 5274955
- Report Number(s):
- DOE/FC/02101-21; ON: DE82014377
- Country of Publication:
- United States
- Language:
- English
Similar Records
Chemistry of lignite liquefaction. Quarterly report, October-December 1981
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Related Subjects
010405* -- Coal
Lignite
& Peat-- Hydrogenation & Liquefaction
ASPHALTENES
ASPHALTS
BITUMENS
BROWN COAL
CARBONACEOUS MATERIALS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL BONDS
CHEMISTRY
CHROMATOGRAPHY
CLEAVAGE
COAL
COAL LIQUEFACTION
COAL LIQUIDS
CRYSTAL STRUCTURE
DATA
ENERGY SOURCES
ETHERS
EXPERIMENTAL DATA
EXTRACTION
FLUIDS
FOSSIL FUELS
FRACTIONATION
FUELS
GAS CHROMATOGRAPHY
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
HYDROGEN TRANSFER
INFORMATION
LIGNITE
LIQUEFACTION
LIQUIDS
MATERIALS
MICROSTRUCTURE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OTHER ORGANIC COMPOUNDS
SEPARATION PROCESSES
SOLVENT EXTRACTION
STRUCTURAL MODELS
SULFIDES
SULFUR COMPOUNDS
TAR
THERMOCHEMICAL PROCESSES