Continuous demulsification of palm oil in water by low electric field

Abstract

Separation of palm oil-in-water emulsion using electric fields was investigated in this study. The experiments were conducted in continuous flow and batch systems. The vessel is made of acrylic plate having a width of 3.0, a length of 8.0 and a depth of 2.5 cm. The electrodes are made of stainless steel having a width of 2.5 and a length of 12 cm. Oil-in-water emulsion consisted of crude palm oil in water at a concentration of 2%wt and sodium sulfate was used as an electrolyte at a concentration of 3.0 mmol. Electric fields were 2, 4, 6, 8 and 10 volts/cm. In continuous flow system, the emulsions flowed pass through the vessel by micro pump at flow rates of 3.0, 5.4, 11, 16 and 20 ml/min. Experimental results show that application of low electric fields to palm oil in water emulsion increased demulsification phenomena. Oil droplets in the electric field were collided to form larger droplets. In a batch system, the percentage of oil content decreased when higher voltage was applied between electrodes. In a continuous flow system, the percentage of oil content decreased when higher voltage was applied and the emulsion flow rate was low.