Dissipative Particle Dynamics (DPD) Study of Crude Oil−Water Emulsions in the Presence of a Functionalized Co-polymer

Abstract

This work presents a theoretical study of the effects of different molecular weights of a triblock co-polymer ethylene oxide/propylene oxide/ethylene oxide, bifunctionalized with ethalamine, on the coalescence of water drops imbibed in a crude oil environment. The polymer/crude oil/water (PCW) time evolution of the emulsion was simulated using the framework of the dissipative particle dynamics (DPD) technique. The bead-bead interactions of the molecular components were calculated using the correlation between the solubility parameter, χ ij , of the Flory-Huggins theory and the conservative force parameter, a ij . The solubility parameter was obtained from atomic molecular models of prototype molecules of saturates, aromatics, resins, asphaltenes, and the triblock co-polymer, through the blend methodology. The dynamic evolution of coarse-grain mesomolecules was carried out in cells of 20 Â 20 Â 20 DPD unit length with periodic boundary conditions. The composition of the emulsion was chosen to be similar to a Mexican heavy crude oil: asphaltenes, 11.9%; resins, 11.8%; aromatics, 42.7%; saturates, 29.6%; polymer, 4%; and two water drops of 3 DPD length units in radius. Finally, a drastic change in the coalescence of water molecules is observed for a short co-polymer length with respect to long co-polymer lengths.

Morphology and Performance of Polymer Solar Cell Characterized by DPD Simulation and Graph Theory

“…Where a ij is a maximum repulsion between particle i and particle j , r ij = r j − r i,, r ij = | r ij | and r ˆ ij = r ij /| r ij | 23 45 50 51 . The inter-particle force is repulsive over a limited range only and acts in the direction of the r ij vector.…”

Molecular Dynamics Simulation of Self-Aggregation of Asphaltenes at an Oil/Water Interface: Formation and Destruction of the Asphaltene Protective Film

“…For example, demulsification of heavy crude oil emulsions in the presence of a functionalized copolymer was investigated by Alvarez et al by using the framework of the DPD simulation. 37 It was found that the copolymer with short-chains was more effective to accelerate the water coalescence than that of with long chains. In this work, an all-atom model was employed by using MD simulation to study the aggregation of asphaltene molecules at the water/ oil interface.…”

Mesoscopic probes in asphaltenes nanoaggregate structure: from perpendicular to paralleled orientation at the water-in-oil emulsions interface

“…13,22 DPD simulations method are an excellent technology for the simulation of coarse-grained systems over considerable length and time scales up to the mesoscopic scale. 13,20 DPD simulations have been performed to study static and dynamic interfacial phenomena and the self-assembly behavior of amphiphilic molecule at the interface, 20,21 including asphaltenes at liquid/ liquid interface 22 and the solid/liquid interface. 23 In this study, we have used three types of asphaltene molecules with different molecular weights, which was constructed from a statistical representation of the oil sample.…”