1. CRYSTALLIZATION
Fractionation by definition is the separation of the liquid portion (Olein) and the solid portion (Stearin) from the mother oil such as palm oil. Dry fractionation is one of the methods used to do this separation. Dry fractionation does not involve any addition of organic or inorganic substances in its process. Crystallization is achieved solely by the cooling down of the oil to the desired temperature whereby certain tri-glycerides crystals will be formed. The resulting slurry (mixture of solid crystals and liquid oil) is ready for filtration.
2. FILTRATION
Separation of the liquid olein and the crystallized stearin is carried out by using membrane filter press. The “drying” of the crystallized stearin that are trapped in the filter chambers is done by pumping olein at pressures up to 16 bar to the membranes plates. The expansion of the membranes caused the solid stearin crystals being compressed thus forcing out the liquid olein through the fine filter clothes. The liquid olein are then pumped to the storage tanks for export or packed for local consumption as cooking oil. The solid stearin cakes are ejected into the stearin melting tank where it is melted and heated up using steam before being sent to the storage tanks for local sales or export.