The Business and Process
The oil palm fruit (looks like a plum) is made up of the outer fleshly mesocarp which gives the palm oil and the kernel (which is inside the hard shell) which gives the palm kernel oil and palm kernel meal/cake. The average recoverable palm oil content from FFB is about 20%. The residues of the FFB i.e. 70% of the gross yield are used as fuel and for mulching.
The Crude Palm Oil yield per hectare is about 2 to 7 tonnes, Palm Kernel Oil yield per hectare is about 0.3 tonnes and Palm Meal/Cake yield per hectare is about 0.4 tonnes.
Crude Palm Oil and Crude Palm Kernel Oil are processed further to produce the following:-
1) Refined, bleached and deodorized palm oil (RBDPO)
2) Refined, bleached and deodorized palm kernel oil (RBDPKO)
3) Palm Stearin
4) Palm Olein
A diagram of the Oil Palm and by-products Production Chain
With regards to Product Scope, EFB Industries’ main products are:-
• Palm Oil
• Palm Kernel Oil
• Palm Kernel Cake or Meal
• Vegetable Oil
The production is in two phases:-
1) Palm Oil (PO), Palm Kernel Oil (PKO) and Palm Kernel Cake or Meal (PKC or PKM) will be processed in the first phase. This will be done in the first 7 years.
2) Olein, Stearin, Vegetable Oil (VO) and Bio-fuel will be processed in the second phase.
The fresh fruit arrives from the field or plantation a bunch or loose fruit. The quantity and quality of the fruits arriving at the processing site will be checked. This is important because the quality standard achieved is initially dependent on the quality of fruits/bunches arriving at the mill. The fresh fruit bunch consists of fruit embedded in spikelet’s growing on a main stem.
Palm Oil Extraction
The fresh fruit bunches will be sterilized. Sterilization involves the use of high temperature wet-heat i.e. pressurized steam, to loosen the fruits from the spikelet.
The fresh fruit bunches will be threshed after sterilization. Threshing involves the use of a rotating or fixed drum equipped with rotary beater bars to detach the fruit from the bunch laving the spikelet on the stem.
The fresh fruit bunches will be mixed and cooked in the digester. Digestion is the process of releasing the palm oil in the fruit through the rupture or braking down of the oil-bearing cells. Digesting the fruit at high temperature helps to reduce the viscosity of the oil, destroys the fruits outer covering (exocarp) and completes the disruption of the oil cells which began in the sterilization process.
The fresh fruit bunches will be then moved to the Twin screw press. Pressing is the process of extracting oil from the digested water material. There will be Hot Water Tank which will have permanent and sufficient quantity of Hot water at a temperature of 90C to 95C for the dilution of the Crude Oil (a fluid mixture of palm oil, water, cell debris, fibrous material and “non-oily solids”) coming from the Twin Screw Press. The objective of the dilution is to separate the oil from its entrained impurities and causes the heavy solids to fall to the bottom of the container while the lighter oil droplets flow through the watery mixture to the top
A Crude Oil collector collects the crude oil from the press and the return oil from the sludge decanter. It protects the Crude Oil pump/Centrifuge pump by retaining nuts, fibres and dirt.
Oil from the top is skimmed off and purified in the centrifuge pump prior to drying in vacuum dryers. The clear oil is decanted into a reception tank. However this clear oil still contains water and dirt. To prevent increasing FFA through autocatalytic hydrolysis of the oil, the moisture content of the oil must be reduced to 0.15% to 0.25%. Reheating the decanted oil and carefully skimming off the dried oil from any engraved dirt removes any residual mixture. The final crude palm oil is cooled and sent to storage tanks.
In order to recover the remaining oil, the lower layer from the clarification tank is sent to the centrifugal separator. The crude palm oil is then dried in vacuum dryers, cooked and sent to storage tanks. The oil storage tanks are normally maintained around 50C, using hot water or low-pressure steam-heating coils, to prevent solidification and fractuation since the rate of oxidation of the oil increases with the temperature of the tanks. Iron contamination from the storage tank may occur if the tank is not lined with a suitable protection coating.
The waste water from the clarifier is drowned off into sledge pits dug for the purpose. The accumulated sludge is often collected in buckets and used to kill weeds in the processing area.
Cracking and Separating Unit for palm nuts
The residue from the press, mixture of fibre and palm nuts, in the Crude Oil Collector is fed into the depericarper where air is channelled to lift the fibre, thus separating the fibre from the nuts. The nuts are passed to a polishing drum at the bottom of the depericarper where pieces of stalks are renewed.
After the conditioning and drying process, the nuts are cracked by nutcrackers to release the kernels. The mixture of cracked nuts and shells are separated using a combination of winnowing and hydrocyclones. The kernels are then dried in hot air silos to moisture content of about 7%.
Palm Kernel Oil Extraction
The dried and cleaned palm kernels are crushed mechanically to obtain better extraction rates (through a better penetration of the heat into seeds). The crushed kernels are pre-heated up to 90-95C in humid condition to make the oil cells burst open and to free the oil. The drier-conditioner then heats up the oil seeds at a temperature between 120 – 121C to make the oil liquid for extraction and eliminate toxins.
A continuous press expeller then presses the oil out of the oil seeds. This oil contains solid particles (foots) that has to treated using a clarification process. After the clarification process, the palm kernel oil are then stored.
The milling process involves the following:-
1) Tipping of Fresh fruit Bunches (FFB) into a hopper and loading into cages
2) Sterilisation with steam
3) Threshing to detach fruits from bunches
4) Digesting by mixing and cooking with steam
5) Pressing to extract the oil
6) Clarifying to remove the impurities
7) Palm Oil storage
8) Nut/Fibre separation
9) Nut Drying
10) Nut Cracking
11) Kernel and Shell Separation
12) Kernel Drying
13) Kernel Oil Extraction and Storage.
a) Thermic Conditioning
c) Oil treatment