What is the difference between physical refining and chemical refining of edible oil?

There are two kinds of edible oil refining methods: physical refining and chemical refining of edible oil. The main difference between physical refining and chemical refining of edible oil lies in the way that how to remove FFA. Chemical refining removes the FFA in the deacidification section while physical refining removes the FFA in the deodorization section.

The physical refining and chemical refining process

Physical refining of edible oil is during the process of distillation to remove the free fatty acids, which is one stage of deodorization. Using edible oil physical refining method, it is necessary that the crude edible oil should be thoroughly degummed to come up with effective results. But this is not applicable to some oil, such as cottonseed oil.

Chemical refining of edible oil removes the phosphatides (gums) in two steps--degumming and deacidification, or in one single process—neutralization. The chemical method is more suitable for oils with high phospholipid levels, like cottonseed oil which contains gossypol that can only be conveniently removed by alkali treatment.

Comparatively speaking, physical refining of edible oil is preferred in that it is a more economical process requiring less chemicals, producing less waste and giving higher oil yields. However both physical refining and chemical refining of edible oil are a step by step refining process to remove phospholipids, pigments, off-flavors, free fatty acids and other impurities in the crude edible oil. So we should consider the characteristic of different crude edible oil, then choose to the best refining method.

Henan Doing Company has professional engineers who can design the edible oil refinery plant according to customer's requirement. We are waiting you to contact Henan Doing Mechanical Equipment Co., Ltd! (Related reading: How much will cost to build an cooking oil refinery plant?)