Wet Dewaxing
Dewaxing & Oil Purification
SRS’ dewaxing unit uses the same proven process as the degumming unit. This system effectively removes the wax found in corn oil. During ethanol production, corn oil makes up about 10 percent of the residual byproduct. However, this corn oil is high in Free Fatty Acids (FFA) and requires pretreatment. SRS’ pretreatment systems handle this by reducing FFA levels. The company employs a non-acidic, water-based dewaxing process for this purpose, ensuring an environmentally friendly and cost-effective solution.
Advantages of SRS Dewaxing System
- Minimal yield loss (typically 1/2 – 1%)
- No chemicals used
- Organic process
Why Dewaxing is Needed
Some vegetable oils, such as sunflower or corn oil, contain waxes that crystallize at lower temperatures, causing turbidity. Wet winterization, combined with neutralization, is an effective method for removing these waxes and improving the oil’s clarity.
The process begins with the neutralization of crude oil. An acid is added to condition the gums, and caustic soda neutralizes the free fatty acids. After the soap stock separates in the first separator, operators move the oil to the Winterizing stage for further processing.
Dewaxing Process Steps
- At this stage, operators add a small amount of caustic soda to set a specific residual soap content in the oil. The soap acts as a wetting agent during crystallization, binding the waxes to water.
- After mixing the caustic soda and oil, the product is cooled to the crystallization temperature, and wax crystals begin to form in the crystallization tanks.
- These wax crystals are then bound to the water, which is added to the crystallizers, aiding in the removal process.
- To reduce the viscosity of the oil, operators carefully heat it and move it to a separator, where it continuously separates the waxy water.
- The oil is washed again to further reduce the residual soap content. During this stage, hot water is added, and the mixture is intensively mixed before separating in a second separator.
- Finally, vacuum drying takes place, ensuring that the oil remains stable and ready for further use.
Benefits of SRS Dewaxing
By using this method, SRS’ dewaxing unit ensures a high-quality, purified oil with minimal loss and no chemical additives. This organic and efficient process supports various industries, such as biodiesel production and food processing, contributing to a more sustainable and cleaner oil refining method.
Process Images
Also check out, “Oils and Fats Processing“