Evaluation of the hydrodynamics generated by agitation and electromagnetic field during the electrocoagulation of oil/water emulsion

Abstract

The performance of breaking oil/water emulsions using the electrocoagulation technique in the presence of a magnetic stirrer or an electromagnetic field (EMF) is reported. A batch electrochemical cell has been used with a simulated oil/water emulsion. Here, a vertical, flat plate Fe anode and stainless steel (SS) cathode were used in an array style. In this study, the effect of the rotation speed and the intensity of the electromagnetic field have been investigated. The main reason is to compare the effect of the hydrodynamic and the magneto hydrodynamic on breaking the oil/water emulsion. Results indicated that the hydrodynamic effect enhanced the removal rate of oil to some extent, and considerably reduced the energy consumption per each kg of oil removed (from 2.36 kW h/kgoil at 0 rpm to 1.46 kW h/kgoil at 300 rpm). Moreover, experiments also indicated that the application of electromagnetic field enhanced the oil separation in a relatively same manner. The best position of electromagnetic field is under the electrodes, where the corresponding arbitrary direction of the magnetic flux intensity is parallel to the surface of the electrodes. During the same time interval, the EMF enhances the oil removal percentage to be 94.8% compared to 72.4% without it. Accordingly, the application of the electromagnetic field in a continuous process would enhance the oil separation at relatively same power consumption.