Effect of ultrasound irradiation on asphaltene aggregation and implications to rheological behavior of bitumen

Molecular Characterization of Remnant Polarizable Asphaltene Fractions Upon Bitumen Upgrading and Possible Implications in Petroleum Viscosity

“…Extra-heavy crude oils and bitumens feature high viscosity (>10 000 cPs) and high density (>1.0 g/mL) or low API gravity (<10.0), which is usually attributed to their high content of heteroatoms (O, N, S, V, and Ni) and increased asphaltene concentration compared to light and medium oils. , Therefore, petroleum companies usually perform in situ upgrading to improve the mobility of extra-heavy fossil fuels . Generally, the goal of upgrading extra-heavy oils, via methods such as visbreaking and hydroconversion, is viscosity reduction, via cracking reactions to decrease molecular weight and/or disruption of intermolecular interactions that likely promote strong aggregation among specific petroleum fractions (e.g., asphaltenes). − Therefore, it is likely that viscosity reduction upon upgrading results from a decrease in the concentration of asphaltenes and resins, known for their higher heteroatom content and stronger aggregation tendencies. Viscosity improvement also arises from increasing the content of saturates and aromatics, with a concurrent decrease of the concentration of sulfur and other molecular features such as aromaticity. , …”

Cavitation-Assisted Transformations in Bitumen Processing: A Review

“…Among the different methods used for reducing the viscosity of bitumen without the usage of additive or excess energy or changing the properties of oil, acoustic cavitation during sonication has been reported. Here, the viscosity reduction due to physical effects of cavitation technology is also based on breaking cohesion between asphaltene and resin molecules due to extraordinarily high transient temperature and pressure in a localized spot within bitumen by the occurrence and collapse of acoustic cavitation. , In another mechanism that was proposed in 2016 by Mohapatra and Kirpalani, the viscosity reduction is due to the chemical effects of cavitation which cause the formation of hydroxyl radicals and consequent disintegration of hydrocarbons leading to change in bitumen composition. The various case studies highlighting the use of cavitation for viscosity reduction are summarized in Table :…”

Asphaltene Modeling, Emulsion, and Aggregation: A Review

“…Models 77,[81][82] or simulations 83 have been attempted to predict aggregation and subsequent issues that asphaltene causes in oil extraction schemes; in one instance, researcher made a model [84][85] to correlate operational parameters and aggregation\precipitation of asphaltene. To provide an overview on system under which asphaltene bulk or interfacial behavior has been studied media can be summarized in broad terms into toluene\water 86 , toluene\decane\water 23,87 , Crude oil\toluene\water 88 , Crude oil 89 , Crude oil and p-xylene 90 , Decane\water 91 , Crude oil [92][93][94] , p-xylene and toluene 87 , Ester oil\water 95 and xylene\water 96 ;…”