Nanoaggregation and Solubility of Crude Oil Asphaltenes from Molecular Dynamics Simulations

The aggregation and solubility of asphaltenes are studied by classical molecular dynamics simulations. Average three-dimensional atomistic models are built on the basis of experimental data for the asphaltenes from a series of crude oil samples. The simulation of two such asphaltene models in four different solvents puts into evidence the formation of oligomeric clusters and gives clues to the initial stages of asphaltene aggregation at the nanometer scale. The Hildebrand solubility parameter is calculated for the whole collection of asphaltene models, as an example of obtaining practically useful physicochemical properties from molecular simulations applied to average asphaltene structures. Key-Words: asphaltene, oil, aggregation, solubility, simulation, molecular dynamics, forcefield, Hildebrand, solvent