Experimental Investigation of Demulsification of Water-in-Oil Emulsions

The formation of highly stable water-in-crude oil (W/O) emulsions during oil production, transportation, and refining presents severe operational, economic, and environmental challenges. This study presents a systematic experimental investigation of the demulsification of stable W/O emulsions under dynamic and static conditions. We investigate the synergetic effects of demulsifier chemical structure (polyethylene glycol (PEG) vs. polypropylene glycol (PPG) block copolymers), concentration (۵۰ to ۲۵۰ ppm), operating temperature (۳۵ °C to ۶۵ °C), and water volume fraction (۱۰ vol.% to ۴۰ vol.%) on Bottle Test Water Separation Efficiency (WSE) and interfacial tension (IFT) reduction. Interfacial rheological profiles and optical microscopy were utilized to examine the film-thinning and coalescence kinetics of water droplets. The results show that a formulation blending high molecular weight PEG-PPG block copolymers with a hydrophobic linker achieves an exceptional water separation efficiency of ۹۸.۵% within ۱۲۰ minutes at ۵۵ °C. This highly efficient performance is attributed to the rapid displacement of indigenous asphaltene-resin film networks at the oil-water interface, as evidenced by a sharp reduction in dynamic IFT from ۳۲.۴ mN/m to ۴.۲ mN/m. The dynamic stability of the film-rupture kinetics presented in this study provides key physical insights for optimizing industrial desalting and dewatering facilities

کلیدواژه ها:

Water-in-Oil Emulsions ، Demulsification ، Coalescence ، Asphaltenes ، Interfacial Tension ، PEG-PPG Block Copolymers