New modeling method to simulate asphaltenes at oil sands process in water management

Abstract

The study of various structures, physicochemical structures and dynamic characteristics of oil-water interface asphaltenes is an important basis for the large-scale development and efficient clean utilization of oil sands. The molecular dynamics simulations method provides a possibility for revealing the physicochemical structure and dynamic characteristics of oil sands. The emphasis of this paper is to study the physic-chemical structure of tar sands asphaltenes and the changes of their kinetic properties by using molecular dynamics simulations. Molecular dynamics was used to simulate the physicochemical and dynamic characteristics of asphaltenes in water treatment of the oil sands. In this research, the structural and dynamic properties of asphaltenes, such as density distribution, correlation (radial distribution function), root-mean-square deviation (RMSD), and mean azimuth shift (MSD), diffusion coefficient, the radius of gyration, volume viscosity and free energy in water treatment were systematically discussed. The simulation results of asphaltene at the oil-water interface revealed that, in the oil-water interface, oil and water will affect the solubility of asphaltene. The asphaltene molecules have different mobility and the ability to break molecular association, indicating that the structure and dynamic properties of asphaltene in the oil-water interface and the water-water interface are different.