Journal ArticleDOI
Molecular Size and Structure of Asphaltenes from Various Sources
TLDR
Fluorescence depolarization measurements are used to determine the size of asphaltene molecules and of model compounds for comparison Mean molecular weights of roughly 750 amu with a range of roughly 500−1000 amu are found for petroleum Asphaltenes are found to have one or perhaps two fused ring systems per molecule as mentioned in this paper.Abstract:
Fluorescence depolarization measurements are used to determine the size of asphaltene molecules and of model compounds for comparison Mean molecular weights of roughly 750 amu with a range of roughly 500−1000 amu are found for petroleum asphaltenes A strong correlation is established between the size of an individual fused ring system in an asphaltene molecule and the overall size of this corresponding molecule, showing that asphaltene molecules have one or perhaps two fused ring systems per molecule Subtle differences in molecular size are found for different virgin crude oil asphaltenes and for a vacuum resid asphaltene Coal asphaltene molecules are found to be much smaller than petroleum asphaltenes The molecular sizes of resins and asphaltenes are found to form a continuous distributionread more
Citations
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Journal ArticleDOI
The Modified Yen Model
TL;DR: Asphaltenes, the most aromatic components of crude oil, are critical to all aspects of petroleum use, including production, transportation, refining, upgrading, and heavy-end use in paving and coating materials as mentioned in this paper.
Journal ArticleDOI
Advances in Asphaltene Science and the Yen–Mullins Model
Oliver C. Mullins,Hassan Sabbah,Hassan Sabbah,Hassan Sabbah,Joëlle Eyssautier,Andrew E. Pomerantz,Loïc Barré,A. Ballard Andrews,Yosadara Ruiz-Morales,Farshid Mostowfi,Richard A. McFarlane,Lamia Goual,Richard Lepkowicz,Thomas M. Cooper,Jhony Orbulescu,Roger M. Leblanc,John C. Edwards,Richard N. Zare +17 more
Abstract: The Yen–Mullins model, also known as the modified Yen model, specifies the predominant molecular and colloidal structure of asphaltenes in crude oils and laboratory solvents and consists of the following: The most probable asphaltene molecular weight is ∼750 g/mol, with the island molecular architecture dominant. At sufficient concentration, asphaltene molecules form nanoaggregates with an aggregation number less than 10. At higher concentrations, nanoaggregates form clusters again with small aggregation numbers. The Yen–Mullins model is consistent with numerous molecular and colloidal studies employing a broad array of methodologies. Moreover, the Yen–Mullins model provides a foundation for the development of the first asphaltene equation of state for predicting asphaltene gradients in oil reservoirs, the Flory–Huggins–Zuo equation of state (FHZ EoS). In turn, the FHZ EoS has proven applicability in oil reservoirs containing condensates, black oils, and heavy oils. While the development of the Yen–Mullin...
Journal ArticleDOI
Air pollution combustion emissions: characterization of causative agents and mechanisms associated with cancer, reproductive, and cardiovascular effects.
TL;DR: Although there is substantial evidence that PAH or substituted PAH may be causative agent in cancer and reproductive effects, an increasing number of studies investigating cardiopulmonary and cardiovascular effects are investigating these and other potential causative agents from air pollution combustion sources.
Journal ArticleDOI
Chemical compositions of improved model asphalt systems for molecular simulations
TL;DR: In this paper, new chemical compositions of model asphalts were proposed to enable molecular simulations that can further an understanding of asphalt physical, rheological, and mechanical properties, and the results provided an improved tool for relating asphalt chemical compositions to Rheological and Mechanical properties.
Journal ArticleDOI
Our current understanding of water-in-crude oil emulsions. - Recent characterization techniques and high pressure performance
Johan Sjöblom,Narve Aske,Inge Harald Auflem,Øystein Brandal,Trond Erik Havre,Ø. Sæther,Arild Westvik,Einar Eng Johnsen,Harald Kallevik +8 more
TL;DR: In this article, a review of water-in-oil emulsions is presented, and it is established that the pressure conditions will influence the behavior of active components and the properties of the interface.
References
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Journal ArticleDOI
Asphaltene Molecular Size and Structure
TL;DR: The rotational correlation times of individual asphaltene molecules have been determined using fluorescence depolarization techniques, addressing an active, long-standing controversy as discussed by the authors, using simple...
Journal ArticleDOI
Theory of Fluorescence Depolarization by Anisotropic Rotational Diffusion
TL;DR: In this paper, the general expressions for the time-dependent fluorescence depolarization caused by anisotropic rotation diffusion have been obtained and the results differ from those of previous studies and the differences are discussed.
Journal ArticleDOI
The molecular structure of asphaltene : an unfolding story
TL;DR: From detailed chemical and thermal degradation studies, a host of structural units have been identified in Alberta asphaltenes as mentioned in this paper, and it has been shown that the extent of aromatic condensation is low and that highly condensed pericyclic aromatic structures are present in very low concentrations.
Journal ArticleDOI
Direct determination and quantification of sulphur forms in heavy petroleum and coals: 1. The X-ray photoelectron spectroscopy (XPS) approach
TL;DR: X-ray photoelectron spectroscopy (XPS) was applied to the problem of speciating and quantifying organically bound forms of sulphur in nonvolatile and solid hydrocarbons as mentioned in this paper.
Journal ArticleDOI
Structural characterization of asphaltenes of different origins
TL;DR: In this article, asphaltenes obtained by precipitation with n-heptane from crude oils of different geological origin have been analyzed by a great number of spectroscopic techniques in order to show the main molecular features which differentiate them.
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Advances in Asphaltene Science and the Yen–Mullins Model
Oliver C. Mullins,Hassan Sabbah,Hassan Sabbah,Hassan Sabbah,Joëlle Eyssautier,Andrew E. Pomerantz,Loïc Barré,A. Ballard Andrews,Yosadara Ruiz-Morales,Farshid Mostowfi,Richard A. McFarlane,Lamia Goual,Richard Lepkowicz,Thomas M. Cooper,Jhony Orbulescu,Roger M. Leblanc,John C. Edwards,Richard N. Zare +17 more