Alkali Refining Plant
Depending on the quality of the Edible oil being refined, one can take a call on whether or not to use Alkali Refining versus more traditional chemical methods. Nevertheless, Alkali refining is here to stay in the future and is a much more preferred option over traditional methods.
Free Fatty Acids in the edible oil are often responsible for oil acidity which why Alkali Refining is employed. In traditional refining methods, boiling point manipulation is used to get rid of the extra FFA however, Alkali Refining neutralizes the FFA. In addition to getting rid of FFA, Alkali Refining also removes non-glyceride material like Phospholipids, Oxidized Products, and Metal Ions etc.
The typical steps to Alkali Refining are:
- Heating the Edible Oil
- Vacuum Drying
The Washing process generally involves heating the oil to a certain optimum temperature and adding wash water directly ahead of the dynamic mixer. A disc separator finally separates the oil and water mixture.
The oil is then fed into a vacuum dryer via a pressure relief valve. The pressure usually maintained in the vacuum dryer is 50-70 milli bars absolute and the large oil surface enables the water to evaporate off the top onto surface condensers.
Soybean Oil, Rape Seed Oil and Sunflower Oil