Monte Carlo Modeling of Asphaltene Aggregation Coupled with Sedimentation

In this article, simultaneous occurrences of aggregation and sedimentation processes of asphaltene particles in toluene and n-heptane mixture are studied. Image processing technique is applied in a settling column setup to evaluate the size distribution evolution at three sections. Each section consists of three distinct zones that are introduced on the aggregate size evolution: the stable, ascending and the descending zones. The effect of the toluene to n-heptane volume ratio (T:H) and the structure of asphaltenes on the size distribution are investigated. The asphaltene aggregates with higher aromaticity factor have more tendencies to aggregate with one another. A time-driven Monte Carlo (MC) model is proposed to predict asphaltene aggregate size distribution during sedimentation in toluene and heptane media. The results of this model are in good agreement with experimental results. By increasing the aggregation probability, the fractal dimension becomes smaller in the simulated case studies.