Palm Oil Mills

Palm Oil Mill

Palm oil is extracted from fresh fruit bunches (FFB) through a mechanical process that ensures the quality of crude palm oil. The primary products obtained in the palm oil mill are palm oil and palm kernel, with biomass as a secondary by-product.

The process stages in a palm oil mill consist of sterilization, stripping, digestion and pressing, clarification, purification, drying, and storage. For the kernels, the stages include nut/fiber separation, nut conditioning and cracking, cracked mixture separation, and kernel drying and storage. The dried kernels are further crushed through mechanical processes or solvent extraction to obtain crude palm kernel oil.

Sterilization

Sterilization is the primary stage, where the bunches are sterilized with live steam at 3 kg/cm². This process deactivates the enzyme lipase, preventing the build-up of free fatty acids. The sterilized bunches are then conveyed to the stripping section, where the fruitlets are detached and taken for further processing in the oil recovery section. The stripped bunches, coming out of the stripper, are conveyed outside the process plant for use as raw material in boilers.

Digestion:

Digestion: The fruitlets obtained from the stripper are fed into the digester, where the purpose is to disrupt the mesocarp of the palm fruit and break up the maximum quantity of oil-bearing cells to facilitate oil release.

Pressing

Pressing: The hot digested mash is then fed into a screw press to extract oil. The resulting mixture of oil, water, and sludge is sent to the oil purification section. The press cake, which contains nuts and fibers, is sent to the nut recovery section.

Clarification

Clarification: The oil-water-sludge mixture from pressing is pumped to a clarifier and allowed to settle. Here, the oil separates from the sludge and water. The clarified oil still contains small amounts of dirt and solid particles, necessitating further purification in a centrifuge.

The purified oil may contain residual moisture, which needs to be removed before storage. This is typically done using a vacuum dryer and vacuum pump. The dried oil is then pumped to storage.