Combination of electric field and medium coalescence for enhanced demulsification of water-in-oil emulsion

Abstract

The efficient separation of water-in-oil emulsions plays significant roles in the petroleum and chemical industries, but deep purification using a single method is difficult. In this work, a combined treatment integrating a direct current electric field and medium coalescence is proposed. The device utilizes an electric field to migrate water droplets, and the fiber medium is used to intercept and capture the droplets. Water droplets migrate rapidly back-and-forth between the electrodes, causing an increase in the rate of droplet-medium collision. The combined treatment showed a significant improvement in the separation performance compared with medium coalescence or electrical demulsification alone, especially improving the ability to process fine droplets. As the applied field strength is increased, the device can achieve a better separation effect with larger throughputs and less residence time. In general, at 10 kV/cm, the separation efficiency increased by approximately 20% compared with that at 0 kV/cm.