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Vegetable oil and fats production process

Process description


Details of vegetable oil business here

There are two extraction technologies, one is mechanical pressing and the other is solvent extraction. The most important factor in the choice of the processing plant, and the processing sequence, is the seed to be extracted, its yield, capacity and the quality of products to be achieved. The minimum capacity recommended for solvent extraction process is 150-200 t /day feed stock. In addition to the above restriction, mechanical presses has the advantage of reduced capital cost, no danger of fire from combustible solvent, simpler process control and smaller number of skilled staff over solvent extraction process. 
The seed requires a thorough cleaning process to remove sand, stalk, plant debris and any foreign matters by rotary or table sieves, usually with air aspiration by fans, and cyclones for dust removal from the air. Then, the seed have to be prepared for efficient oil recovery. The stages involved in pre-treatment are:

a) Size reduction of the seeds by breaking them, usually in fluted roller mills;
b) Flaking of the seed particles in roller mills with smooth roller surfaces (0.2 -0.3 mm);
c) Conditioning the seed by adjusting their moisture content and temperature, while keeping the seed hot (say 90-950C) for periods that vary widely (30-60 minutes). Then, extraction by using high pressure screw press follows.

The crude oil obtained from the press requires undergoing refining processes to produce a bland tasting, light coloured oil without odour or flavour. To obtain fully refined oil from crude oil, the following steps are necessary: degumming, neutralizing, bleaching,

Winterizing and deodorizing. The refined oil is, then, packed and marketed. The refined oil containing unsaturated fatty glycerides are by partial hydrogenation rendered into fats of more suitable composition for edible purposes. The hydrogenation process consist of the following two process steps; hydrogenation and post hydrogenation refining stages (the refining process mentioned above)
Source: Shreves, Chemical process Industries

Vegetable oil production process video


The main waste material from oil manufacture is water and much attention should be given to the water treatment to avoid its adverse effect in the environment. Biological treatment by aerating, activated sludge system, addition of flocculating agent and filtration are used before the effluent is discharged.