Self-Accumulation of Uncharged Polyaromatic Surfactants at Crude Oil-Water Interface: A Mesoscopic DPD Study

摘要

The dissipative particle dynamics (DPD) technique was applied to study the behavior of several uncharged perylene bisimide-based polyaromatic surfactant (PAS) molecules, with the same polyaromatic core but with different terminal functional types (TP, C5Pe, PAP, and PCH) at the crude oil-water interface. We considered the SARA crude oil model with Persian Gulf oil field composition, which includes saturates, 59%; aromatics, 28.5%; resins, 9.7%; and asphaltenes, 2.8% at two temperatures 298 and 363 K. The DPD interaction parameters for the bead pairs needed in the DPD simulations were evaluated by using the well-known correlation equation, where the required Flory-Huggins interaction parameter in this equation was calculated by the blend methodology model. The results indicated that the C5Pe terminal functional type of PAS is absorbed more effectively on the water droplet interface in the crude oil system and can reduce the interfacial tension (IFT) to facilitate the oil-water separation. The results of this simulation can be used to choose proper demulsifier surfactant for application in various processes in the oil industry as well as enhanced oil recovery (EOR).