Dewaxing is not a compulsory process and it is not required for every type of oil. It is performed only for high wax containing oils such as Sunflower Oil, Rice Bran Oil, Corn Oil etc.
Oil dewaxing, also called winterization, is typically used at corn and sunflower-processing vegetable oil refineries. It improves the oil’s clarity and brightness by removing solids—saturated glycerides or waxes—that are visible at ambient or low temperatures.
Vegetable oil dewaxing steps:
Crude oil is reﬁned and bleached to low phosphorus (<1ppm) and low moisture content (<0.1%).
The oil is heated to 55˚C to make sure the oil is fully liquid. This is already achieved in the Cooler Vessel while reducing the deodorization temperature.
The oil is then slowly cooled 10–15˚C. Cooling helps for the same.
The cooling oil is stored into the Insulated Crystallizers with a special slow-speed mechanical agitator.
Preferably, the oil is held for several hours at this temperature.
Crystal formation in the oil defines the completion of cooling.
Special transfer pump will slowly feed the slurry to the Filter press.
Filtration yields clear liquid oil and the by-product waxes as output.