Results 171 to 180 of about 6,740 (225)
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Electrokinetic Characterization of Asphaltenes and the Asphaltenes−Resins Interaction
Energy & Fuels, 2003The electrophoretic mobility of asphaltene particles formed by precipitation induced by the addition of n-heptane to asphaltene solutions in toluene was measured in water and in nonpolar media. Dispersed in water, the particles presented a negative electrophoretic mobility, whereas in toluene their mobility was positive and around 2.0 × 10-9 m2/V s ...
Gaspar González +4 more
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Squalene in Petroleum Asphaltenes
Science, 1981Squalene, 2,6,10,15,19,23-hexamethyl-2,6,10,14,18,22-tetracosahexaene, a new biological marker, has been detected in various petroleum asphaltenes and their pyrolysis products. Since squalene is the most common triterpenoid in nature and the biological precursor of the important tetra- and pentacyclic triterpane markers, its detection in asphaltene ...
N, Samman +4 more
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The Fractal Aggregation of Asphaltenes
Langmuir, 2013This paper discusses time-resolved small-angle neutron scattering results that were used to investigate asphaltene structure and stability with and without a precipitant added in both crude oil and model oil. A novel approach was used to isolate the scattering from asphaltenes that are insoluble and in the process of aggregating from those that are ...
Michael P, Hoepfner +3 more
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Stability and Aggregation of Asphaltenes in Asphaltene−Resin−Solvent Mixtures
Energy & Fuels, 2004The Integral Equation Theory (IET) of fluids and molecular dynamics (MD) simulations have been used to study the stability and aggregation of asphaltenes in asphaltene−resin mixtures with different host solvents (n-heptane, toluene, and pyridine).
A. Ortega-Rodriguez +3 more
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Asphaltene Characterization: Sensitivity of Asphaltene Properties to Extration Techniques
Canadian International Petroleum Conference, 2001Abstract One step in asphaltene extraction is to wash the precipitated asphaltenes with the precipitant to remove trapped resinous material. To assess the effect of washing on asphaltene properties, asphaltenes were extracted with three different degrees of washing.
H. Alboudwarej +3 more
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The Role of Asphaltene Solubility and Chemical Composition on Asphaltene Aggregation
Petroleum Science and Technology, 2003Abstract Asphaltenes from four different crude oils (Arab Heavy, B6, Canadon Seco, and Hondo) were fractionated in mixtures of heptane and toluene and analyzed by small angle neutron scattering (SANS). Fractionation appeared to concentrate the most polar species into the least soluble sub-fraction as indicated by elemental analysis.
Keith L. Gawrys +2 more
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Organic Geochemistry, 1984
Abstract Asphaltenes derived from both oil and source-rocks have been studied by pyrolysis-gas chromatography. The pyrograms obtained at 450 and 550°C show that asphaltene structure is very close to the structure of the kerogen of the same sample. They can be interpreted as kerogen moieties, resulting from its early evolution.
F. Behar, R. Pelet, J. Roucache
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Abstract Asphaltenes derived from both oil and source-rocks have been studied by pyrolysis-gas chromatography. The pyrograms obtained at 450 and 550°C show that asphaltene structure is very close to the structure of the kerogen of the same sample. They can be interpreted as kerogen moieties, resulting from its early evolution.
F. Behar, R. Pelet, J. Roucache
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A Mesoscopic Model for an Asphaltene and Complex Mixtures of Asphaltenes
Petroleum Science and Technology, 2015A representation for an asphaltene system and asphaltene mixtures is proposed based on experimental data reported by Socrates et al. These were modeled at the mesoscopic level by applying dissipative particle dynamics (DPD), where DPD beads correspond to the main structure that constitutes the real asphaltene fraction.
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The luminescence of asphaltenes
Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 19701. The luminescence spectra of chloroform solutions of resins and asphaltenes, isolated from mazut, as well as components extracted from asphaltenes with petroleum ether, heptane, and benzene, were measured. 2. The luminescence of solutions of asphaltenes is due to the asphaltenes themselves, and not to resins that might have been ...
V. I. Kazakova, A. F. Koretskii
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Petroleum Science and Technology, 1998
ABSTRACT We report x-ray scattering measurements on asphaltenes and bitumen solutions, with attention to the concentrated regimes. We characterize the data in terms of a correlation length which is indicative of proximity to phase separation in a mixture, rather than the radius-of-gyration more indicative of individual colloids.
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ABSTRACT We report x-ray scattering measurements on asphaltenes and bitumen solutions, with attention to the concentrated regimes. We characterize the data in terms of a correlation length which is indicative of proximity to phase separation in a mixture, rather than the radius-of-gyration more indicative of individual colloids.
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