Chemical refining means chemically removing FFA (acid-base neutralization). In refining process, it utilizes alkali liquor to neutralize the acid in crude oil. But after edible oil degumming and deacidification process, the soap will be produced, usually, we need to use washing method or centrifugal separation method to process soap. Then, in bleaching process, under vacuum, activated clay is used to remove coloring matters and adsorb any metal ions. Same purpose as physical refining of edible oil, the deodorization section mainly used to remove off-flavors and odors in crude edible oil by the help of steam distillation.
The chemical refining is the traditional edible oil refining methods, the chemical refining adaptability is strong, the requirements for raw oil is not high. That is to say, it can be used to refine most crude edible oil, such as soybean oil, peanut oil, sunflower oil, cottonseed oil, rapeseed oil, rice bran oil, mustard oil, palm oil, palm kernel oil and so on.