Oil Refining Plant Degumming Process Hydrated Water And Lecithin Recovery

The degumming process in an oil refining plant removes the gum impurities from crude oil by physical or chemical methods, and it is the first purification step before deacidification, decolorization and deodorization. After screw pressing and solvent extraction, crude oil is mainly made up of triglycerides together with a small amount of non-triglyceride material. That non-triglyceride fraction, including phospholipids, proteins, phlegmatic material and sugars, reacts with triglycerides to form colloids which are known as gum impurities.

Gum impurities not only reduce the stability of the oil but also spoil the effect of the later refining steps. Non-degummed oil readily forms an emulsion during alkaline refining, which increases the difficulty of operation, the refining loss and the consumption of auxiliary materials. In the decolorization step, non-degummed oil raises the consumption of adsorbent and lowers the bleaching effect, so gum removal is essential as the first stage of the refinery process. The most common method in edible oil refining is hydrated degumming, which removes the hydratable phospholipids and some non-hydrate phospholipids.

• Hydrated degumming: hot water or an electrolyte solution is added to the hot crude oil to condense and settle the gums.
• Phospholipid removal: extracts hydratable phospholipids together with proteins, diglycerides and mucilage.
• Lecithin recovery: the extracted gums can be processed into lecithin for food, animal feed or technical use.
• Protects later steps: prevents emulsion in alkaline refining and cuts adsorbent consumption in bleaching.
• Three line types: intermittent, semi-continuous and fully continuous lines to suit the plant capacity.
• Easy to integrate: runs together with the deacidification, decolorization and deodorizing machines.

The degumming section is the first stage of every edible oil refining line, handling crude oil from soybean, rapeseed, peanut, sunflower, cottonseed, corn germ and rice bran. Plants producing 1 to 10 t per day use intermittent equipment, plants of 20 to 50 t per day use semi-continuous equipment, and plants above 50 t per day use fully continuous equipment, with the intermittent hydrated degumming line being the most widely used.

The degumming section is shipped as skid mounted vessels, pumps, mixers and piping with all flanges protected and the stainless steel surfaces coated for transport. We provide flow diagrams, a reaction schedule and a commissioning service, together with a twelve month warranty on the reaction vessels, mixers and pumps.