How Does An Industrial Sunflower Oil Refinery Plant Work?

Oct 30, 2026

Sunflower oil is easy to extract but difficult to refine. Seeds are easily extracted by pressing or solvent extraction. Crude oil still contains phospholipids, free fatty acids, pigments and lots of natural wax. These impurities need to be removed in the right order at the right temperature. If improperly removed, the finished oil can become cloudy in the bottle and smell foul during storage.

An Industrial Sunflower Oil Refinery Plant uses a series of chemical and physical steps to remove impurities. The process must also retain tocopherol, which protects oil from oxidation.

Step One: Degumming

The first stage involves removing phospholipids, also known as gums. If they stay in oil, they can accumulate on the surface of the heat exchanger and reduce the effect of bleached clay in the next phase.

Hydrating the phosphatides in water can be easily removed. They are then separated from the oil by centrifuges. Some seed oils contain more non-hydratable phospholipids. For these oils, acid degumming uses food-grade phosphoric acid acid or citric acid to alter the form of these compounds, which can be separated. The selection depends on the quality of the crude oil and the next refining steps.

Properly treated sunflower oil is usually easy to degummed. Seeds stored for too long or at too high a temperature can produce oil with higher phosphorus levels. This oil needs a stronger acid treatment. More acid treatment also leads to more oil remaining in the gum phase. This means poor seed storage and disposal can increase refining costs.

Step Two: Neutralization, or Physical Deacidification

Free fatty acids must be removed. There are two main approaches. The level of FFA in crude oil usually determines which method is used.

Chemical neutralization involves adding caustic soda to convert free fatty acids into soap. Soap is then removed with hydrated gums in a centrifuge. This approach is reliable and works across a wide range of FFA levels. But it produces soap and some neutral oil that stays in the river. The oil also needs to be cleaned to remove any remaining soap. Modern plants use multi-stage centrifuges. They can also add a small amount of caustic sodium to improve the response. The oil in the soap can then be recovered by acidification. This will increase oil production.

Physical refining removes free fatty acids by steam distillation under high vacuum and temperature conditions. It also combines this step with deodorizing. This method does not use caustic soda. It also eliminates washing step and reduces fuel consumption. But before this stage, a good degumming process is needed. Phosphorus must be low. If the temperature is too high, it can blacken the oil and cause heat damage.

The high FFA content of sunflower oil from improper seed treatment can be physically refined. However, the degumming stage phosphorus must first be reduced to the prescribed level.

Step Three: Bleaching and Filtration

Sunflower oil contains carotenoids, small amounts of chlorophyll and oxidation products. These compounds make oil darker and greener than the market usually wants. Bleach uses activated clay to remove these compounds. The amount of clay added is usually about 0.1% -2% of oil weight. This process takes place in a vacuum and at high temperatures. This helps reduce oxidation during treatment.

Two operational details are important. First, using too much clay increases costs. More clay also contains more oil in used clay. This would cause direct oil losses. Secondly, control exposure conditions. If the vacuum is too low or the contact time is too long, the hot oil will oxidize during treatment. Refineries may remove color but reduce the shelf life of oil.

Filter to remove used clay. Leaf leaf filters are commonly used. The oil in the filter cake can also be recycled and returned to the process at a reasonable cost.

Step Four: Dewaxing and Winterization

This step is important in refining sunflower oil. Sunflower oil naturally contains wax. The wax dissolves at room temperature but form crystals in the fridge. This will make the oil look muddy. Consumers may think the murky oil has gone bad.

Wintering controls the temperature of the oil and causes the wax to form crystals. Crystals need to be large enough to be filtered. Two factors are important: cooling speed and stirring. Rapid cooling produces many small crystals. These crystals can pass through filters or clog filters. Slow, controlled cooling and gentle stirring produce larger crystals. These crystals are easier to remove. Some plants add crystalline aids to aid the filtration process.

Filtering is done at low temperatures. This step can cost more because the oil becomes thicker as it cools. The filtration area and pump capacity must be large enough to accommodate cold oil flow.

Sunflower wax can be sold as a by-product. It can be used for different industrial applications.

Step Five: Deodorization

The final stage is to remove volatile compounds that cause odors and unwanted odors. It also removes free fatty acids from physical refining process and breaks down peroxides. Deodorant heats the oil to a high temperature, usually 240-260 °C. This process takes place in a deep vacuum. Add steam to remove the volatile compounds.

Treatment must be strong enough to remove these compounds. But it cannot be so strong that it converts unsaturated fatty acids into trans fats or destroys tocopherols. Phenolic compounds help protect sunflower oil from oxidation during storage. Sunflower oil is high in a high linoleic acid content. This makes it more sensitive to these problems than oils with more saturated fat. As a result, a well-run industrial sunflower refinery adjusts the deodorization conditions feedstock rather than using the same setup all year round.

Utilities, Control, and Quality Verification

These stages are only part of the plant. Vacuum generation, steam supply, cooling water temperature and heat recovery also affect the cost and performance of industrial sunflower refineries. Deep vacuum is one of the most important utilities. If the vacuum system doesn't work well, the deodorization time can become too short and leave some volatile compounds in the oil. Factories may also need more steam and heat to solve the problem. Both increase costs and reduce profits.

Process control uses conventional metrics rather than operator judgement. Phosphorus, FFA, color, peroxide value, humidity and wax content are checked at set point. The results show whether the intermediate product can move to the next stage or needs to be processed again. Each shipment is tracked from oil intake to finished oil storage. This helps with product release and food safety audits.

Frequently Asked Questions

Why does sunflower oil need protection from the cold and not other oils?

Sunflower oil contains natural wax. The wax can form crystals and cloud oil when it is refrigerated. Crystals form from the wax over winter and are filtered to remove it. This helps to keep the finished oil clean during normal storage and display.

What is the difference between chemical and physical refining of sunflower oil?

Chemical refining uses caustic soda to remove free fatty acids. This creates soap bubbles that must be separated from the oil. The oil also needs to be cleaned to remove any remaining soap. Physical refining removes free fatty acids by steam distillation under high temperature and vacuum conditions. It does not use caustic soda and does not require washing step. But the phosphorus level required for degumming is much lower.

Does refining remove vitamins from sunflower oil?

Deodorization reduces tocopherol in sunflower oil. This happens because the process requires high temperatures and vacuums. Operating conditions matter. Processes designed for raw materials remove unwanted volatile compounds and retain more natural antioxidants. A more rigorous process removes more tocopherols.

Can industrial sunflower oil processing plant process other seed oils?

Many plants can handle other seed oils by changing the degumming and neutralization settings. But sunflower oil production equipment, especially the winterization section, is based on the wax content of sunflower oil. When the raw material changes, the entire refining process needs to be inspected and tested.