Edible Oil Dewaxing Machine

Cooking Oil Dewaxing Process

Main Steps of Oil Dewaxing Process

Conventional dewaxing is the common oil dewaxing method with the working principle of freezing and then mechanically separating oil wax without any auxiliary means, the separating methods are usually pressure filtration, vacuum filtration, and centrifugal separation. Conventional dewaxing is the simplest oil crystallization and filtration method.

First of all, the oil crystallization is carried out in the cooling chamber at 0~4℃, after 72 hours of cooling, the final oil temperature in the oil tank is around 6~10℃. The average cooling rate is 2℃/hour at the first 24 hours of the cooling period, the cooling rate of the next 24 hours is 0.5℃/hour and the last 24-hour' cooling rate is 1~2℃/hour. Then, the oil and precipitated wax crystals are separated by bag filtration in the filtration room at 15~18℃, and the filtration time is around 10~12 hours. The available filtration bags are polyester card, cotton, or cotton fabric, and their filtering speed is polyester card>cotton>cotton fabric.

At present, most of the oil refining plants are cooling, crystallizing, and plate filters separating oil from the wax paste. Oil such as sunflower seed oil contains less wax which could be dewaxed by cooling to 10~15℃ for 2 days and then pumping to the plate filter with compressed air. The dewaxing effect is good with a wax content in dewaxed oil is only ten milligrams per kilogram.

In general, conventional dewaxing is simple and cost-effective, but the wax separation is not complete and has a high cloud point which could be through crystallizing filtration twice.

Main Dewaxing Equipment

• Cooling system
• Heat exchanger
• Crystallizing tank
• Maturing tank
• Filter

Precautions for Edible Oil Dewaxing Machine

1. Before cooling, oil should be heated firstly to make the wax that has been precipitated at room temperature(wax precipitates when room temperature is lower than the crystallization temperature.)completely dissolved in oil liquid, which can enhance the following dewaxing effect.
2. The oil cooling speed should be even which shouldn't be too fast.
3. After cooling for 72 hours, the crystallized wax needs to be matured for 12~16 hours to make it grow big.
4. When separating, you can use two plate filters for filtering to keep continuously working.

Oil Dewaxing and Fractionation Distinction

1. Oil dewaxing and fractionation are based on the same principle, but they have different purposes. Dewaxing is by removing wax content to improve the palatability and quality of the oil. Fractionation is done by using the differences in glycerol's melting point and solubility to obtain solid fats and liquid oils from raw materials.
2. During oil dewaxing winterization, oil is kept at a low temperature for a period of time and then filtered to remove solid impurities that can cause liquid oil to become cloudy.
3. Oil fractionation is a modified process, which involves a larger change in the material components and improves the physical properties of the oil product. For example, fractionated coconut oil contains a large amount of medium-chain fatty acids like caprylic acid(C8)and capric acid (C10)that may lead to modest weight loss and provide several other health benefits.