A novel oxygen-containing demulsifier for efficient breaking of water-in-oil emulsions

A novel aliphatic alcohol nonionic polyether (MJTJU-2) has been successfully synthesized by esterification and polymerization. It is found that this new polyether is efficient in fast demulsifying the water-in-oil emulsions, including water-in-diesel emulsion, water-in-crude oil emulsion, water-in-asphalt oil emulsion and water-in-asphaltenes solution emulsion, etc. Take the most stable emulsion (interfacially active asphaltene (IAA)-stabilized emulsions) as an example, almost complete dehydration (>97%) to the emulsions could be achieved in less than 15 min at 60 °C using 400 ppm of MJTJU-2. This demulsification of IAA-stabilized emulsions is much faster than other reported work by traditional or commercial demulsifiers (up to several hours). To comprehensively understand how the MJTJU-2 influence the demulsification efficiency, the operational parameters (e.g., demulsifier dosage, temperature, settling time) have been systematically investigated and optimized. The excellent performance of MJTJU-2 in demulsifying the oil-water emulsions is considered mainly to be ascribed to the rich hydrophilic groups (i.e., hydroxyl, ester groups, carboxyl groups, ether groups) in the demulsifier molecules. These oxygen-containing groups help to break the IAA-formed film at the oil-water interface, which would be replaced by newly formed bonding. These findings suggest that the MJTJU-2 demulsifier would be potential engineering efficient process aids for the demulsification of water-in-oil emulsions.