Edible Oil Refinery

Some oils that are rich in very high content free fatty acids are needed to refine before using for cooking. The foremost aim of refining process is removing extra free fatty acids and preventing the oils from oxidation. However, the refinery process is not only limited to remove FFA (Free Fatty Acids), it also removes the undesired components, color and odor which otherwise may have a negative impact on the taste, odor, and appearance of the product. The resultant oil is thinner without FFA, colorless and odorless. The following processes are followed in edible oil refinery plants.

Neutralization of crude oil by removing free fatty acids: In this process the oil is neutralized in the neutralizer to remove the Free Fatty Acids by agitation with caustic soda (NAOH). Oil is heated up to about 60°C by thermic fluid coils and oil is stirred by stirrer. The fatty acids are settled at the bottom as alkali soaps which is known as soapstock from where it is taken out into soap pan.

Removal of impurities and color: Neutralized oil is passed into the second vessel called bleacher where color of oil is removed by bleaching process with the aid of chemicals such as carbon black and bleaching earth. Oil is generally heated up to 110°C by thermic fluid coils. Stirring is also continued. Bleaching process is done under vacuum. Bleached oil then goes to filter press where bleaching earth and chemicals are removed and cleaned.

Removal of unpleasant smell: Bleached oil is then passed to deodorizer where oil is heated above 110°C through thermic fluid coils and then live steam is applied to the oil from the bottom steam nozzles. The temperature of oil is raised up to 200 to 220°C through thermic fluid coils. Entire process is done under high vacuum. Thus smell is removed from the oil in the deodorizer. Then it goes to cooler where cold water circulating coils take away heat and oil is cooled.

Micro filtration: Micro filtration is done after the cooling process in cooler. This process is done in a micro filter press which makes the final output oil that is Refined Cooking Oil. The filter press is specially designed for better filtration and better quality of final refined cooking oil.

Additional Process for palm oil refinery: In addition to usual refinery process palm oil is required another additional process, fractionation process, where palm olene and palm sterene are separated by cooling the refined palm oil in chilling plant. For this purpose crystalizing vessel is used in which chilling pipe coils cool the oil for fractionation. Palm sterene crystals are formed due to chilling which are separated in the filter press and pure liquid of palm olene is obtained and palm sterene cake is retained in the filter press.

About the Author:

Thomas Scott invites you to take a look at Wooshin NTI. The foremost aim of Edible Oil Refining Process is removing extra free fatty acids and preventing the oils from oxidation.