Oil-in-water emulsions are frequently generated during crude oil and natural gas production, exhibiting varying degrees of stability depending on their composition and operating conditions. Efficient separation of these emulsions is essential for downstream processing and water management, typically achieved through flocculation followed by demulsification. However, the physicochemical relationships governing emulsion stability and breaking efficiency remain insufficiently understood. In this study, the performance of several commercially available flocculants was systematically evaluated using a multi-method characterization approach. Demulsification efficiency was correlated with interfacial tension, zeta potential, and phase separation behavior across emulsions with varying oil contents. The results reveal clear relationships between electrostatic destabilization, interfacial activity, and separation efficiency. Among the tested systems, a flocculant mixture consistently exhibited superior performance, which is attributed to its favorable interaction with the oil–water interface and its ability to effectively reduce electrostatic repulsion between droplets. The study provides a comprehensive framework for linking physicochemical properties to demulsification performance, offering practical insights for optimizing emulsion breaking in petroleum production and water treatment processes. • Commercial flocculants were evaluated for crude oil emulsion breaking. • The most effective flocculant achieved complete phase separation. • Efficient demulsification required both interfacial tension reduction and droplet destabilization. • Zeta potential analysis supported the optimization of flocculant dosage. • Oil content strongly influenced demulsification efficiency and separation behavior.
Bejczi et al. (Fri,) studied this question.