In the fractionation plant which involves the process of crystallization and filtration, the refined palm oil is again processed by which the two following products are produced:
- RBD Palm Olein
- Palm Stearin RBD (Refined Bleached Deodorised)
RBD Palm Stearin Production Process
Unrefined palm oil is imported, processed and refined into refined palm oil. The method for acquiring RBD palm stearin is as follows:
Crystallization
RBD palm oil is first heated through a plate heat exchanger prior to being fed into the crystallizer. There is more or less constant feeding of oil into the crystallizers. The crystallizer is prepared for the cooling program once the oil reaches high levels.
The cooling process with each crystallizer is managed by a programmable controller based on an individual microprocessor. For initial pre-cooling, cooling tower water is used, thus conserving energy. The applicant is able to obtain a crystallized slurry, which is known to be much more appropriate for the membrane filtration device, because of the large cooling surface in the crystallizer compared to the amount of oil.
The cooling period is completed within a couple of hours for each crystallizer. The crystallized sludge can then be filtered inside the membrane filtration system.
Filtration
The partially crystallized RBD palm oil is fed by the filter feed pump to the membrane filter press. With single squeezing air/hose attachment, close delivery, hydraulic press closing type, and 3 pieces detachable rubber membrane type, the filter is of a mixed packed shape.
The filtrate, i.e. olein, passes via a suitable porosity filter cloth and flows along the rubber membrane’s corrugated channels that wrap behind the filter cloth and directs the olein from the filter frame into a closed discharge channel into the olein receiver tank.
At the point when the chambers are loaded up with cake, for example, stearin, the feed is topped and high-weight liquid (typically compacted air) is conceded behind the membrane which being versatile, presses or crushes the stearin mass in the chamber liberated from fluid olein formed inside the interspaces of the crystals out into the release channel following the way of the filtrate.
The frames are hydraulically opened when the squeezing process is finished and solid stearin falls into a melting tank of stearin. During the next period of operation, the filter press is then closed.