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U.S. Department of Energy
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Chemistry and structure of coal-derived asphaltenes, Phase III. Quarterly progress report, July--September 1977

Technical Report ·
DOI:https://doi.org/10.2172/5258694· OSTI ID:5258694

The major benzene insoluble fraction, carboid, solvent-separated from Synthoil coal liquid, was found to be 90 wt.% soluble in pyridine. This fraction, which contains about 50% of the ash present in Synthoil coal liquid, could be 96% de-ashed by dissolution in pyridine. A hypothetical average structure for Synthoil asphaltene has been derived from analytical, VPO MW, x-ray, NMR and chemical functionality data. A self-association model has been developed for calculating molecular weights, and fractions of monomeric, dimeric and trimeric asphaltene species present as a function of concentration in benzene solution. ESR measurements of Lande g-values and spin intensities have been made for coal liquid solvent fractions and asphaltene derived products. The observed g-values fall within the narrow range (2.0028 to 2.0036) previously reported for asphaltic fractions of petroleum and neutral radicals. TGA measurements of coal liquid fractions have been carried out, and % char values determined. Synthoil asphaltene has been found to undergo oxygen induced reactions which stabilize it toward volatilization vis-a-vis the Synthoil carboid fraction. Silylation studies on carboid coal-liquid fractions afforded % OH/Q/sub total/ values: Synthoil, 47; HRI H-Coal, 64; FMC-COED, 52; Catalytic Inc., 36; PAMCO, 53. Methylation studies of Synthoil asphaltene, with methyl iodide, indicate that about 67% of the asphaltene nitrogen is non-basic, and that about 33% of the nitrogen in molecules containing basic nitrogen is non-basic.

Research Organization:
University of Southern California, Los Angeles (USA)
Sponsoring Organization:
USDOE Office of Fossil Energy (FE)
OSTI ID:
5258694
Report Number(s):
FE-2031-9
Country of Publication:
United States
Language:
English