Study on Synergistic Demulsification Mechanism of Microwaves and Ionic Liquids on Heavy Oil Emulsions

Heavy oil-in-water (O/W) emulsions must be treated before refinement and transportation, and microwave and ionic liquid (IL) synergistic effects are stable, efficient, and environmentally friendly methods of demulsification. In this study, the synergistic effects of various IL anion and cation types and concentrations upon microwave emulsion demulsification were investigated. The interfacial tension (IFT) and zeta potential of the ILs and the distribution of oil droplets were measured before and after microwave radiation using a spinning drop tensiometer, zeta potential analyzer, and biological microscope to elucidate the synergistic mechanism of microwave and IL demulsification. The results indicate that microwave radiation parameters that are set too high or low can have an inhibitory effect on demulsification. When [C16MIM]Br with a concentration of 1 mmol/L was used as the IL, and the microwave radiation parameters were set to 300 W for 30 seconds, the demulsification efficiency reached 89.29%, which was 3.23 times and 2.08 times higher than the individual demulsification efficiency of microwave radiation and IL, respectively. This study provides a novel approach for examining high-performance demulsification, and it extends the applicability of microwave-IL synergy.