Processing of Fresh Fruit Bunches (FFB) into Crude Palm Oil (CPO)
The process of processing Fresh Fruit Bunches (FFB) into Crude Palm Oil (CPO) is a series of mechanical and thermal stages aimed at separating the oil from the fruit flesh (mesocarp) with the highest possible efficiency while keeping the free fatty acid (FFA) content low.
The following are the systematic stages in a palm oil mill:
1. Fruit Reception
FFB from the plantation is transported by truck and weighed on a weighbridge to determine gross and net weights. Sorting is then carried out to ensure the fruit ripeness meets the standard before the bunches are loaded into the loading ramp.
2. Sterilization
The FFB is loaded into a pressurized steam vessel (sterilizer) using saturated steam at a pressure of around 2.83.0 kg/cm. This process aims to:
- Stop the activity of the lipase enzyme that triggers an increase in free fatty acids (FFA)
- Facilitate the detachment of loose fruits from the bunch
- Soften the fruit flesh so that the oil is easier to extract
3. Threshing
The sterilized fruit is then processed in a thresher machine. At this stage, the loose fruits are separated from the empty fruit bunches through rotation and beating mechanisms. The empty fruit bunches can subsequently be utilized as organic material.
4. Digestion
The loose fruits enter a digester tank equipped with stirring blades. The process is carried out at high temperature (9095C) to break down the cell structure of the fruit flesh (mesocarp), releasing the oil and facilitating subsequent extraction4.
5. Extraction/Pressing
The mashed fruit mass is then processed using a screw press. This process produces a mixture of oil, water, and solids (sludge), as well as press cake consisting of fiber and nuts5.
6. Clarification
The liquid from pressing then enters the clarification stage to separate the oil from water and impurities. This process generally involves:
- Sand Trap Tank for settling sand
- Continuous Clarifier Tank for separation based on specific gravity
- Further separation such as centrifugation or vacuum drying to reduce moisture and impurity content6
7. Kernel Recovery
The press cake is further processed to separate fiber and nuts using a depericarper. The nuts are then cracked (ripple mill), and the palm kernels are separated using methods such as hydrocyclone or claybath before being dried as a by-product7.
References
Pre-treatment of Oil Palm Fruits: A Review
https://www.sciencedirect.com/science/article/pii/S0260877414002635
Minimizing Water Consumption in Oil Palm Sterilization Using Direct Steaming
https://www.sciencedirect.com/science/article/abs/pii/S0260877421003307
Effects of Sterilization Time on Fruit Separation and CPO Quality
https://www.akademiabaru.com/submit/index.php/aram/article/view/1872
4 Palm Oil Processing (FAO Corporate Document Repository)
https://www.fao.org/3/Y4355E/y4355e04.htm
5 Recovery of Residual Oil from Palm Oil Mill Effluent Using Polypropylene Nanofiber
https://grdspublishing.org/index.php/matter/article/view/1784
6 Recent Advances in Palm Oil Milling and Clarification Processes
https://www.sciencedirect.com/science/article/pii/S0926669023015200
7 Palm Oil Mill Effluent Treatment ProcessesA Review
https://www.mdpi.com/2227-9717/9/5/739