Palm Kernel Pretreatment
Palm kernel pre-treatment is indispensable to get pure palm kernel oil; more important, the clean palm kernel is a favor to protect oil press and extend its working life. After removing palm kernels shells by palm kernel shelling and separator machine, the shelled palm kernels need the following processing steps.
a.Vibrating screen is used here to sieve sand, stones and other debris; at the same time, magnetic separators are adopted to separate metal debris.
b. A crushing machine is necessary to break the whole palm kernel into several pieces.
c. The kernel pieces are fed in a roller mill. The palm kernel cake thickness becomes thinner and thinner as it drops from the top to the bottom, about 0.25 to 0.4 mm thick.
d. The kernel flakes are then conveyed to cooking to adjust the moisture content and ensure pure oil.
Palm Kernel Oil Pressing Step
The pretreated palm kernel material is then transferred to the screw oil press for extraction. Equipped with the automatic temperature-controlling device and crude oil filter tank, Our integrated screw oil press operates easily and has high oil output. After pressing, the crude palm kernel oil is filtered through the filter cloth and stored in tanks temporarily, when the de-oiled cakes are discharged out. One more thing that the feeder is not just a common feeder but specially designed which ensures the feeding continuously and averagely; thus the pressing process is smooth and efficient.
Palm Kernel Oil Refining
Like other oil seeds refining process, palm kernel oil refinery has to follow four steps which are degumming, neutralization, decoloring and deodorizing.
1. At degumming section, hot water is used here as materials like phospholipids and gums are soluable in oil but not in water.Thus the impurities are separated. Some of them are made into lecithin or added to cakes for flavor. Degumming can improve palm kernel oil edibility and extend storage time.
2. Neutralization is also known as deacidification. Alkali is the main material to neutralize free fatty acids and convert it to soaps which are removed away under centrifugal force.
3. At the decoloring stage, bleaching earth or clay is added to the crude palm kernel oil and heated. The oil is mixed with bleaching earth and keep the mixing and reaction continuously. After decoloring, the bleached oil should be filtered to remove residues created in this step.
4. Palm kernel oil deodorization is the last but not least stage in the oil refinery. The bleached oil is deaerated and heated and deodorized under high pressure. After going through the heat exchanger, the deodorized oil should be cooled and filtered. The free fatty acid is collected as by-products.
5. Palm kernel oil’s wide market share in edible oil industry raises an urgent claim on edible oil processing crafts. Although the pressing techniques are close to being mature, we still should pay attention to the advanced techniques and endeavor to offer people purer palm kernel oil.