Asphaltene Mesoscale Aggregation Behavior in Organic Solvents
Date
2019-01-10
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Abstract
Asphaltenes have received significant attention over the past decade, primarily because of their complex self-assembly behavior that results in their aggregation and deposition either in the reservoir formation or the production facilities. The aggregation and deposition of asphaltenes causes severe problems in both upstream and downstream sectors of the petroleum industry. For this reason, significant effort has been expended in shedding light on the basic molecular and colloidal properties of asphaltenes to identify the key parameters controlling their stability in the crude oil mixture. Molecular simulations provided invaluable information on the main molecular mechanisms leading to the asphaltene aggregation and also the principal intermolecular forces governing this process. However, the high computational cost of these simulation approaches did not allow the scientists to fully produce the aggregation behavior of asphaltenes in the past. In this work, we aimed at studying the asphaltene self-assembly behavior at mesoscales wherein the primary colloidal particles portray the asphaltene nanoaggregates. The Brownian dynamics (BD) simulations have been utilized to investigate the aggregation behavior of asphaltenes in different solvent environments at various volume fractions of asphaltene nanoaggregates under no- and simple shear-flow conditions. The BD simulations enabled us to access significantly larger length and time scales compared to the molecular simulations resulting in complete reproduction of asphaltene aggregation hierarchy. The effects of asphaltene volume fraction, solvent quality, and the shear rate on the kinetics of aggregation, the internal structure of the formed aggregates, and the self-diffusion coefficients of asphaltenes were also discussed.
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Asphaltene, Aggregation, Fractal, Brownian Dynamics, Percolating Networks, Diffusion Coefficient, Shear-Flow, No-Flow
Citation
Ahmadi, M. (2019). Asphaltene Mesoscale Aggregation Behavior in Organic Solvents (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.