After the palm oil milling process, the crude palm oil proceeds to the refinery for further purification and enhancement. The refinery stage involves the following steps:

Degumming: The crude palm oil is heated and mixed with water to remove gums and other impurities. This process helps improve the oil’s stability and appearance.

Neutralization: In this step, the oil is treated with an alkaline substance, such as sodium hydroxide, to neutralize any free fatty acids present. This neutralization process ensures the oil’s suitability for various applications.

Bleaching: The neutralized oil undergoes a bleaching process, which involves the addition of bleaching earth or activated carbon. This step helps remove pigments, residual impurities, and any undesirable odors, resulting in a clear and odorless oil.

Deodorization: To eliminate volatile compounds and further enhance the oil’s sensory properties, deodorization takes place. The oil is heated under vacuum conditions, and steam is passed through it to remove any remaining odors and flavors.

Refining equipment: Oil refining pot, decolorization pot/tower, deodorization pot/tower

Continuity of each process: degumming, deacidification, bleaching, deodorization

1. Intermittent refining: Each process is not continuous; suitable for small scale and needs to process different cooking oil

2. Continuous refining: Each process is carried out continuously; suitable for large scale and high production efficiency

3. Semi-continuous refining: Degumming and deacidification in batches, decolorization or deodorization continuously.