The process of separating triglycerides of high and low melting points by crystallization at low temperature followed by filtration of solid and liquid fractions using membrane filters is known as dry fractionation. Separated fractions have a wide variety of applications in the culinary industry. The two main processes in dry fractionation are:

1. Crystallisation: Refined oil is first preheated to 65^o C to maintain consistency and then fed to the crystallizer where it is cooled in a predetermined manner. Process parameters can be monitored and controlled with the help of PLC to form crystals. Once crystals are formed in the Eco Cool crystallizer, (observed through the sight glass), the slurry containing crystals are sent to the membrane filter press for separation of crystals from oil.
2. Filtration: Slurry conveyed from crystallizer to the Membrane Filter Press, where solid and liquid phases are separated. The solid phase (stearin) is retained in the filter as cake, and the olein passes through the olein tube as filtrate. Olein from the cake is recovered by squeezing the stearin cake with the help of air or liquid.

Application

Dry fractionation is used for Palm and Palm Kernel Oil