Dissipative Particle Dynamics-Based Simulation of the Effect of Asphaltene Structure on Oil–Water Interface Properties

Abstract

Asphaltenes are the main substances that stabilize emulsions during the production, processing, and transport of crude oil. The purpose of this research is to investigate the process of asphaltenes forming interfacial films at the oil−water interface by means of dissipative particle dynamics (DPD) and the effect of asphaltenes of different structures on the oil−water interface during the formation of interfacial film. It is demonstrated that the thickness of the interfacial film formed at the oil−water interface gradually increases as the asphaltene concentration rises and the amount of asphaltene adsorbed at the oil−water interface gradually multiplies. Both the number and type of heteroatoms in asphaltenes affect the interfacial behavior of asphaltenes. The interface activity of asphaltenes can be enhanced by increasing the number of heteroatoms in the asphaltene, and the type of heteroatom affects as well the interfacial activity of the asphaltene as it affects the aggregation behavior of the asphaltene in the system. As the number of asphaltene aromatic rings increases, the oil−water interfacial tension (IFT) trends down gradually, while the effect of alkyl side chains on the reduction of IFT of asphaltenes is different, and asphaltenes with medium length alkyl side chains can reduce IFT more efficiently.

Self-assembly of rigid amphiphilic graft cyclic-brush copolymers to nanochannels using dissipative particle dynamics simulation

“…In some of the previous studies, the interaction parameter between benzene and water was set to 90 when the bead number density was ρ = 3 based on the experimental solubility parameter values. 39 Benzene is an extremely insoluble substance in water, and the value of this interaction parameter indicates that it is extremely hydrophobic. Therefore, in our simulation, 100 is set as the upper limit of the interaction parameters, thus guaranteeing that the interaction parameter settings from 25 to 100 can cover enough parameter space.…”

Mechanistic Study of the Effects of Surfactants and Asphaltenes on the Action of Emulsions with Different Water Contents: Based on Dissipative Particle Dynamics

“…r c is the truncation radius, which represents the range of interaction between the beads. The other two forces in eq are the dissipative force F ij D and the random force F ij R , and their expressions are shown below. ,, F i j R = σ w R ( r i j ) θ i j r̂ i j F i j D = prefix− η w D ( r i j ) ( r̂ i j × v i j ) r̂ i j …”

“…The other two forces in eq 1 are the dissipative force F ij D and the random force F ij R , and their expressions are shown below. 21,36,37 = F w r r ( )…”

Mesoscopic Simulation of Aggregate Characteristics of Asphaltene Molecules Under Shear Fields

“…Liang et al got similar results. Liang et al studied the interfacial characteristics of the oil–water interface with asphaltene. − Guan et al simulated a variety of heavy oil dissolution systems with continental asphaltene molecules, using the SU-DPD method. The results were consistent with the Yen-Mullins model and experimental results.…”