Dewaxing Dewaxing and Winterisation of Edible Oils are basically the Separation of Oils and the waxes with different melting points. In the Winterisation process, the oils are cooled in a simple way and kept at a low temperature for sometime. The liquid and the solid fractions are separated by filtration. In the Dewaxing process, the cooling of the oil and the separation of the waxes are done in a more sophisticated way, under controlled conditions.

Dry Oil Dewaxing
The principle of this process is based on cooling of oil under controlled conditions with or without the addition of certain chemicals as wetting agents. The liquid and solid phases are separated generally by filtration.

Miscella Dewaxing
The principle of this process is based on cooling and crystallisation in the presence of one or two solvents along with the oil. The liquid and solid phases are separated by filtration in hermetically sealed filters. Both the wax and the Oil miscella are then distilled separately to separate the solvent.

Miscella Dewaxing process though more complex in nature is the only process by which complete dewaxing is possible to pass cold test. Loss of neutral oil through waxes will be very much less in Miscella Dewaxing compared to Dry Dewaxing Process resulting in higher yield of neutral oil in the process.

AUM Consultancy Pvt. Ltd., Madras have developed the process to incorporated Miscella Dewaxing Process in Solvent Extraction Plants to dewax the oil produced in the solvent extraction plant.

The design of Dewaxing Process demands the following four successive stage:

Gradual Cooling of the Oil/Miscella to supersaturation, resulting in the formation of nuclei for crystallisation.

Progressive growth of crystals by maturation.

Separation of the wax crystals by filtration and recovery of the neutral oil and the wax.

Provide regenerative heat exchangers for energy conservation.

The process involves mainly pumping of metered quantity of the oil and solvent in the required proportion through a mixer. The resulting miscella is subjected preliminary cooling with water and then with cold dewaxed miscella miscella. The cooled miscella continuously transferred to a series of crystallisers maintaining the required temperature of the miscella for forming wax crystals and maturation. The wax crystals are separated in hermetically sealed filters. The filtered wax is washed with cold solvent before the same is heated and sent for distillation.