Chemistry of lignite liquefaction. Quarterly report, October-December 1981
Asphaltene and preasphaltene samples were isolated by solvent extraction using toluene and tetrahydrofuran, respectively, from GFETC liquefaction runs 44-14, 44-12, 45-15, 46-16 and 58-15. All the forty series samples were prepared from North Dakota lignite while 58-15 was from a Texas lignite. The quantity of preashpaltenes and asphaltenes in the five samples were 4.5 +- 0.5% wt and 13 +- 3% wt, respectively. The majority of the lignite was converted into distillable oils. The samples contain 7 to 10% wt oxygen for the preasphaltenes and 4 to 6% wt for the asphaltenes. The preasphaltene/asphaltene ratio of oxygen was 1.5 +- 0.1 for a given run. Approximately 50% of the oxygen is phenolic and the remainder we assume to be etheral types. In comparing process conditions, higher reaction pressures led to lower aromaticity and degree of condensation in the products, but had little effect on the oxygen content for the asphaltenes and raised the oxygen percentage for the preasphaltenes. Understanding the Catalytic Role of H/sub 2/S in Low-Rank Coal Liquefaction: One postulate on the mechanism of H/sub 2/S promotion of liquefaction is by means of its conversion into elemental sulfur in intermediate stages. Consequently, elemental sulfur was reacted with compounds postulated to approximate the crucial chemical bonds of coal which are necessary to rupture for liquefaction: diphenylmethane, bibenzyl, diphenyl ether and N,N-dimethylaniline. The reactions quickly proceeded at liquefaction temperatures to give a variety of products. A portion of these products are lower in molecular weight than the starting materials. Some of the products have been identified. N,N-dimethylaniline is demethylated with either elemental sulfur or H/sub 2/S sequentially via N-methylaniline.
- Research Organization:
- North Dakota Univ., Grand Forks (USA)
- DOE Contract Number:
- AB18-78FC02101
- OSTI ID:
- 5384374
- Report Number(s):
- DOE/FC/02101-20; ON: DE82016705
- Country of Publication:
- United States
- Language:
- English
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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
CLEAVAGE
COAL
COAL LIQUEFACTION
COAL LIQUIDS
CRYSTAL STRUCTURE
DATA
ELEMENTS
ENERGY SOURCES
ETHERS
EXPERIMENTAL DATA
EXTRACTION
FLUIDS
FOSSIL FUELS
FRACTIONATION
FUELS
HYDROGEN COMPOUNDS
HYDROGEN SULFIDES
INFORMATION
LIGNITE
LIQUEFACTION
LIQUIDS
MATERIALS
MICROSTRUCTURE
MOLECULAR WEIGHT
NONMETALS
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OTHER ORGANIC COMPOUNDS
SEPARATION PROCESSES
SOLVENT EXTRACTION
STRUCTURAL MODELS
SULFIDES
SULFUR
SULFUR COMPOUNDS
TAR
THERMOCHEMICAL PROCESSES