Polydispersity of asphaltenes in toluene

Conference · Wed Aug 01 04:00:00 EDT 1990 · American Chemical Society, Division of Petroleum Chemistry, Preprints; (United States)

OSTI ID:7067439

Sheu, E Y; Liang, K S; Sinha, S K; Overfield, R E ^[1]

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1. Exxon Research and Engineering Co., Annandale, NJ (United States)

Asphaltenes have been reported to exhibit colloidal behavior in solutions. However, the thermodynamics of their self-association and the resulting particle polydispersity was not yet fully investigated. In this paper, the authors measured the structure and polydispersity of the asphaltene particles in toluene using small-angle neutron scattering (SANS). To study their self-association they systematically increased the solution temperature to observe the evolution, if any, of the particle structure and size. In order to determine the asphaltene size distribution and the corresponding polydispersity they fitted the SANS data with a polydispersity model in which one more adjustable parameter (than monodisperse analysis) was used to account for the particle size distribution. Because of one more free parameter used in data fitting, an ambiguous result due to multiple convergence may lead to a misinterpretation. In order to minimize this ambiguity and obtain a realistic particle size distribution they developed a method by which one can self-consistently verify the obtained particle size distribution. From SANS data analysis they found that the Schultz distribution function properly described the asphaltene particle sizes and the polydispersity decreases whenever temperature or concentration increases.

• OSTI ID: 7067439
• Report Number(s): CONF-900802--
• Conference Information: Journal Name: American Chemical Society, Division of Petroleum Chemistry, Preprints; (United States) Journal Volume: 35:4
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
023000* -- Petroleum-- Properties & Composition
ALKYLATED AROMATICS
AROMATICS
ASPHALTENES
ASPHALTS
BITUMENS
COHERENT SCATTERING
COLLOIDS
CRYSTAL STRUCTURE
DIFFRACTION
DISPERSIONS
DISTRIBUTION
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROCARBONS
MATHEMATICAL MODELS
MICROSTRUCTURE
NEUTRON DIFFRACTION
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
PARTICLE SIZE
PETROLEUM
PETROLEUM FRACTIONS
PETROLEUM RESIDUES
PHYSICAL PROPERTIES
QUANTITY RATIO
SCATTERING
SIZE
SMALL ANGLE SCATTERING
TAR
TEMPERATURE MEASUREMENT
THERMODYNAMIC PROPERTIES
TOLUENE