What Are the Solvent Extraction Method for Soybean Oil?

Soybean oil is extracted from soybeans, which have an oil content of less than 20%, lower than other oilseeds like rapeseed, peanuts, and sesame. To maximize efficiency, soybean oil is generally extracted using the solvent extraction method. Only small oil mills and high-end oil producers use the pressing method to produce soybean oil.

The cleaned soybeans undergo a series of treatments including dehulling, crushing, flaking, and extruding. The extruded soybeans are then sent to the extraction workshop, where oil is extracted using solvents (usually hexane). The extracted oil is then refined to remove solvent residues, gums, pigments, and other impurities. The refined soybean oil is typically classified as first-grade soybean oil。

Soybean Oil Extraction Process Steps

1. Pre-treatment:

Clean the soybeans to remove impurities, then dehull, crush, and flake them to increase surface area for better oil extraction.

2. Extrusion:

Extruding the processed soybeans to loosen their structure, making it easier for the solvent to penetrate.

3. Extraction:

Send the expanded soybeans to the extractor, where oil is extracted using solvents (usually hexane). The solvent mixes with the soybean flakes, dissolving the oil to form miscella.

4. Solvent Recovery:

Separate the solvent from the miscella through evaporation and stripping, obtaining crude soybean oil. This step is crucial and involves strict control of temperature, pressure, and flow rates.

5. Refining:

Refine the crude soybean oil to remove solvent residues, gums, pigments, and free fatty acids, resulting in refined soybean oil.

Currently, over 90% of soybean oil on the market is processed using the solvent extraction method. solvent extraction remains the predominant method for most manufacturers.