Biodiesel/Water/Glycerol Emulsion Separation Using Electrocoalescence: Model and Process Emulsions

The application of electrical fields in emulsion separation in the biodiesel production process was investigated. Two sets of experiments were performed; first, electrostatic demulsification on water-in-biodiesel model emulsions was carried out. These emulsions were prepared using biodiesel derived from soybean oil and castor oil and with a water content of 10% w/w. The electrostatic separation of model emulsions showed an acceptable efficiency with the final water contents of less than 1% w/w in most cases. The second phase of the study was carried out by producing castor oil biodiesel via transesterification in the laboratory. The separation process, after reaction and product (biodiesel) washing, was performed by electrostatic destabilization at various electrical fields. The results of the electrostatic demulsification were compared with centrifugation and decanting as conventional separation techniques. Promising results were obtained in the separation of biodiesel from water and glycerol by the application of electrostatic treatment.