Variation in the chemical nature of asphaltenes with the process, the coal and the reaction conditions

Journal Article · Wed May 01 04:00:00 EDT 1985 · Liq. Fuels Technol.; (United States)

DOI:https://doi.org/10.1080/07377268508915380· OSTI ID:6242863

Kershaw, J R

Average structure data for twelve asphaltenes are reported, based on /sup 13/C- and /sup 1/H- n.m.r. spectroscopy combined with elemental, molecular weight and functional group analyses. The asphaltenes were from supercritical gas extraction, flash pyrolysis and hydrogenation of a brown and a bituminous coal. The effect of the reaction temperature and, for hydrogenation, the catalyst and solvent on the nature of the asphaltene produced was studied. The asphaltene obtained from supercritical gas extraction of the brown coal at 350/sup 0/C was the least aromatic (f/sub a/=0.44) with the highest H/C atomic ratio (1.16) and probably consists mainly of single ring aromatics with about half of the aromatic sites substituted. A significant proportion of the carbon in this asphaltene is in long alkyl chains and the hydroxyl content is high. Whereas, the asphaltenes produced by hydrogenation of the bituminous coal at 450/sup 0/C were far more aromatic with more highly condensed but less substituted aromatic ring systems and few, if any, long alkyl chains, together with a lower hydroxyl content. The asphaltenes obtained from the brown coal are less aromatic with less condensed aromatic ring systems but a higher degree of aromatic substitution than those produced from the bituminous coal under the same conditions. The asphaltenes formed at 450/sup 0/C had lower H/C atomic ratios, molecular weights and degree of aromatic substitution, but higher aromaticities than those produced at 350/sup 0/C or 400/sup 0/C under like processing conditions. The asphaltene produced in the presence of both stannous chloride catalyst and tetralin was less aromatic than when either of these species was absent. 22 references, 2 figures, 6 tables.

• Research Organization: CSIRO, Melbourne, Australia
• OSTI ID: 6242863
• Journal Information: Liq. Fuels Technol.; (United States), Journal Name: Liq. Fuels Technol.; (United States) Vol. 3:2; ISSN LFTED
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010403 -- Coal & Coal Products-- Hydrogenation-- (-1987)
010405 -- Coal
Lignite
& Peat-- Hydrogenation & Liquefaction
010406 -- Coal & Coal Products-- Pyrolysis & Cracking-- (-1987)
010600* -- Coal
Lignite
& Peat-- Properties & Composition
ALKYLATED AROMATICS
AROMATICS
ASPHALTENES
ASPHALTS
BITUMENS
BITUMINOUS COAL
BLACK COAL
BROWN COAL
CARBON
CARBONACEOUS MATERIALS
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL ANALYSIS
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
COAL
DATA
DECOMPOSITION
ELEMENTS
ENERGY SOURCES
EXPERIMENTAL DATA
EXTRACTION
FOSSIL FUELS
FUELS
HYDROCARBONS
HYDROGEN
HYDROGENATION
INFORMATION
MAGNETIC RESONANCE
MATERIALS
MOLECULAR WEIGHT
NITROGEN
NMR SPECTRA
NONMETALS
NUCLEAR MAGNETIC RESONANCE
NUMERICAL DATA
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXYGEN
PYROLYSIS
QUANTITATIVE CHEMICAL ANALYSIS
RESONANCE
SEPARATION PROCESSES
SOLVENT EXTRACTION
SPECTRA
STRUCTURAL CHEMICAL ANALYSIS
SULFUR
SUPERCRITICAL GAS EXTRACTION
TAR
TEMPERATURE DEPENDENCE
TETRALIN
THERMOCHEMICAL PROCESSES
TOLUENE