In order to get the pure and refined oil, there are three main process in chemical palm oil refinery plant and chemical palm kernel oil refinery plant: degumming process, bleaching process and deodourising process.
Physical Refining is the steam distillation of free fatty acids from oils and fats under high temperature and vacuum conditions.

The deodorization tower is mainly used for oil deodorization. It is a kind of distiller used to remove odor in the distillate under high temperature and high vacuum. It is commonly used for distillation of heat sensitive materials or separation of substances and impurities with high boiling point under normal pressure. The deodorization tower is the main equipment for plant oil in production of cooking oil and salad oil. In addition, in the deodorization and distillation of oil, the boiling points of odor components and oil are different, even under the same temperature, the saturated vapor pressure of odor components is larger and the boiling point is lower, while the saturated vapor pressure of oil is smaller with higher boiling point. So the odor component is a low boiling point volatile substance, easy to be removed from the oil. Next, in the deodorization process, free fatty acids can be removed simultaneously, and the smoke point, the color and the stability of the oil can be improved.