Chemistry and structure of coal-derived asphaltenes, Phase III. Quarterly progress report, January--March 1978

Technical Report · Sun Jan 01 04:00:00 EST 1978

DOI:https://doi.org/10.2172/6570986· OSTI ID:6570986

Yen, T. F.

The solubility limits of Synthoil and PAMCO asphaltenes have been measured as a function of Hildebrand solubility parameters and hydrogen bonding. Solvents with moderate hydrogen bonding capacity such as dioxane, ethyl benzoate and dibutyl phthalate were found to be most effective in dissolving asphaltenes over the widest range of solubility parameters. VPO molecular weight studies of coal liquid derived carbenes, as a function of concentration in the solvent THF, indicate that these fractions are more strongly self-associated than the corresponding asphaltenes, and generally afford high infinite dilution number average molecular weights: Synthoil, 861; HRI H-Coal, 1156; Cat. Inc. SRC, 1228; PAMCO SRC, 1054. The variable ESR temperature dependence of the spin intensity for a Synthoil asphaltene-I/sub 2/ charge transfer followed a 1/T (Curie--Weiss) dependence over the temperature range from 25/sup 0/ to -114/sup 0/C suggesting that independent, non-interacting donor and acceptor doublets were formed. Weight percent OH values, determined from 'H NMR analysis of silylated asphaltenes, were found to provide a reasonably linear correlation with the absorbance of the monomeric OH infrared stretching bands of the asphaltenes.

• Research Organization: University of Southern California, Los Angeles (USA)
• Sponsoring Organization: USDOE
• OSTI ID: 6570986
• Report Number(s): FE-2031-11
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010405 -- Coal
Lignite
& Peat-- Hydrogenation & Liquefaction
010600* -- Coal
Lignite
& Peat-- Properties & Composition
ASPHALTENES
ASPHALTS
BITUMENS
CARBENES
CHEMICAL BONDS
CHROMATOGRAPHY
COAL LIQUEFACTION
COMPARATIVE EVALUATIONS
DENSITY
ELECTRON SPIN RESONANCE
INFRARED SPECTRA
LIQUEFACTION
MAGNETIC RESONANCE
MOLECULAR WEIGHT
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANIC SOLVENTS
OTHER ORGANIC COMPOUNDS
PHYSICAL PROPERTIES
RADICALS
REFRACTIVITY
RESONANCE
SEPARATION PROCESSES
SOLUBILITY
SOLVENTS
SPECTRA
SRC PROCESS
SYNTHOIL PROCESS
TAR
THERMOCHEMICAL PROCESSES