Fractionation and characterization of Utah tar sand bitumens: Influence of chemical composition on bitumen viscosity

Conference · · Energy and Fuels; (United States)

OSTI ID:5529404

Bukka, K; Miller, J D; Oblad, A G ^[1]

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1. Univ. of Utah, Salt Lake City (USA)

The highly viscous nature of the bitumen was understood, based on a model developed by Nellensteyn, to arise from a dispersion of asphaltenes in viscous oils with constituent aromatics and resins acting as suspension stabilizers. In a recent related study by Christensen et al., it was shown that for an Asphalt Ridge (Utah) bitumen the viscosity increased with an increase in asphaltenes content. Variation in the asphaltene content of the bitumen was accomplished by a prior fractional separation of the bitumen into maltenes and asphaltenes and mixing these fractions together in various proportions. From the colloidal suspension model for bitumen and the results of Christensen et al., it may appear that asphaltenes alone are responsible for the observed high viscosity of bitumen. However, a comparative analysis of Athabasca (Alberta, Canada) and Asphalt Ridge bitumens, particularly in terms of their viscosities and asphaltene contents, reveals otherwise. Asphalt Ridge bitumen, though containing only 7% asphaltenes, has a viscosity value of 80 Pa{center dot}s at 50C whereas Athabasca bitumen, which has 17% asphaltenes, has a viscosity of only 5 Pa{center dot}s at 50C. These results indicate that in addition to asphaltenes there are other compositional properties of the bitumen which influence its viscosity. In this paper a detailed analysis consisting of fractionation and characterization of Asphalt Ridge and Sunnyside bitumens was undertaken in order to determine what compositional properties other than asphaltene content may influence bitumen viscosity. The results suggest that a discrete group of compounds present in the polar fractions of the bitumen may have a significant influence on bitumen viscosity and may be of equal, if not greater, importance than the asphaltene content. The interpretation of the observed results not only lends support to the model of Nellensteyn, but also identifies another compositional factor which determines bitumen viscosity.

• DOE Contract Number: FC21-89MC26268
• OSTI ID: 5529404
• Report Number(s): CONF-900802--
• Conference Information: Journal Name: Energy and Fuels; (United States) Journal Volume: 5:2
• Country of Publication: United States
• Language: English

Related Subjects

04 OIL SHALES AND TAR SANDS
040500* -- Oil Shales & Tar Sands-- Properties & Composition
AROMATICS
ASPHALT RIDGE DEPOSIT
ASPHALTENES
ASPHALTS
ATHABASCA DEPOSIT
BITUMENS
BITUMINOUS MATERIALS
CARBON 13
CARBON ISOTOPES
CARBONACEOUS MATERIALS
CHEMICAL COMPOSITION
COLLOIDS
CORRELATIONS
DEVELOPED COUNTRIES
DISPERSIONS
ENERGY SOURCES
EVEN-ODD NUCLEI
EXTRACTION
FEDERAL REGION VIII
FOSSIL FUELS
FOURIER TRANSFORMATION
FRACTIONATION
FUELS
GEOLOGIC DEPOSITS
INFRARED SPECTRA
INTEGRAL TRANSFORMATIONS
ISOTOPES
LIGHT NUCLEI
MAGNETIC RESONANCE
MASS BALANCE
MATERIALS
MOLECULAR WEIGHT
NORTH AMERICA
NUCLEAR MAGNETIC RESONANCE
NUCLEI
OIL SAND DEPOSITS
OIL SANDS
ORGANIC COMPOUNDS
ORGANIC POLYMERS
OTHER ORGANIC COMPOUNDS
PETROCHEMICALS
PETROLEUM PRODUCTS
POLAR COMPOUNDS
POLYMERS
RESINS
RESONANCE
SAMPLE PREPARATION
SEPARATION PROCESSES
SOLVENT EXTRACTION
SPECTRA
STABLE ISOTOPES
SUNNYSIDE DEPOSIT
TAR
TRANSFORMATIONS
USA
UTAH
VISCOSITY