First process is neutralizing the oil in the neutralizer to remove the Free Fatty Acids (FFA) by adding caustic soda. Then soap stock formed due to chemical reaction is separated from the oil in centrifuge.
Neutralized oil is drawn into the second vessel called bleacher where colour of oil is removed by bleaching process with aid of clay or chemicals such as carbon black and bleaching earth. Oil is generally heated up to 110°C by
thermic fluid coils. Bleaching process is done under vacuum.
thermic fluid coils. Bleaching process is done under vacuum.
Bleached oil then goes to the filter press where bleaching aids and chemicals are separated and clean bleached oil is then drawn to deodorizer where oil is heated above 110°C through thermic fluid coils and then live steam is given to the oil from the bottom steam nozzles and temperature of oil is raised up to 200 to 220°C through thermic fluid coils. Entire process is done under high vacuum. Thus smell is removed from the oil in the deodorizer. Then it goes to cooler where water circulating coils take away heat and oil is cooled. Again it goes to second filter press where completely refined and transparent color less oil is obtained.