1. Crude Oil Degumming: In this step gums in crude oil are removed by hydration with the help of phosphoric acid.
2. Neutralization: In this step, free fatty acids are neutralized by using sodium hydroxide and convert them into soap.
Additional impurities are also removed by adsorption on the soap.
3. Bleaching: During bleaching, unwanted pigments are adsorbed physically and oil will become much clearer.
4. Deodorization: Deodorization is used to remove unacceptable odors by steam distillation, the odoriferous compound are
stripped off with the help of live injected steam into heated oil under high vacuum pressure.
5. Dewaxing (necessary for cold areas)