Demulsification by increasing the gravitational force acting upon the dispersed phase owing to the adsorption/absorption of the magnetite particles

Abstract

Demulsification using a magnetic demulsifier is commonly used to separate emulsions using an external magnetic field. However, this study presents a new demulsification method based on the increased weight of the dispersed phase due to the adsorption/absorption of the magnetite particles by the droplets. Micron-sized bare magnetite particles were used as the demulsifier in this method which does not necessarily need to apply a surface-active additive and the magnetic field for the demulsification. Magnetic responsivity of the demulsifier can only be used for the recovery of the demulsifier. The demulsification experiments were performed using the oil-in-water and water-in-oil emulsions. The effect of temperature, wettability, demulsifier dosage and activity, sedimentation rate and particles size were investigated. The results showed that the proposed method can remarkably improve the efficiency and speed of the demulsification, and has a great potential to be considered for the commercialization.

Graphical Abstract

Keywords:

• Magnetic demulsifier
• emulsion
• interface
• particles adsorption
• particles absorption

Acknowledgment

The authors acknowledge Dr. Mohammad Mahdi Doroodmand, Department of Chemistry, College of Sciences, Shiraz University, Shiraz, Iran for taking his ultrasonic homogenizer. The authors are also grateful to the Shiraz University for supporting this research.