Glycol-Based Ionic Liquid Demulsifiers: An Efficient Approach for Enhanced Separation of Crude Oil Emulsions

This study reported the effectiveness of newly grown glycol (GL)-based ionic liquid demulsifiers, named GL360, GL690, and GL700, according to their molecular weights. The ability of these demulsifiers to destabilize emulsions and separate oil and water into distinct phases was characterized by bottle tests at 90 °C, and their concentrations varied from 50 to 200 ppm. The demulsification mechanism and adsorption kinetics of these GL demulsifiers were evaluated through bulk viscosity, stress analysis, and interfacial tension measurements. Demulsification results from the bottle tests demonstrated that these demulsifiers possessed great oil–water separation performance, with the best separation efficiency realized at 100 ppm, which was 97.5%, 99.8%, and 99.3% for GL360, GL690, and GL700, respectively, for emulsions produced from distilled water, while NaCl expedited the breaking ability of these chemical demulsifiers. More importantly, these demulsifiers destabilized emulsions efficiently into water and oil phases under acidic and alkaline conditions, with GL690 exhibiting 99.5% (acidic state) and 99.8% (alkaline state) demulsification efficiency, respectively. Likewise, the destabilization kinetics of the produced emulsions, monitored through viscosity and stress determinations, revealed a sharp reduction in the viscosity and stress of formulated emulsions in the presence of GL360, GL690, or GL700 demulsifiers, while the interfacial tension (IFT) measurements explained the influx and adsorption of GL360, GL690, and GL700 at the oil–water interface. With the attainment of equilibrium after 650 s, the IFT values of the blank solution as well as GL360, GL690, and GL700 solutions in contact with crude oil were measured to be 9.95, 3.7, 2.65, and 1.63 mN/m, respectively. These chemical demulsifiers are easy to synthesize and are suitable for separation processes.