Oliver C. Mullins

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.

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...

TL;DR: 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.

TL;DR: This work combines atomic-resolution imaging using atomic force microscopy and molecular orbital imaging using scanning tunnelling microscopy to study more than 100 asphaltene molecules, constituting a paradigm shift for the analysis of complex molecular mixtures.

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...