Efficient Soybean Oil Extraction Process with Advanced Equipment

The main function of soybean extraction equipment is to extract oil from pretreated soybean cakes using fresh solvent through countercurrent circulation and to recover solvent from wet meal and miscella. The crude oil obtained undergoes refining to produce high-quality soybean oil.

The extraction process has five stages:

Soybean Oil Extraction: 

Fresh hot solvent sprays countercurrently in the extractor, separating oil and meal. Oil transfers from solid to liquid phase due to concentration differences, completed through molecular and convective diffusion.

Desolventizing, Drying, and Cooling Meal:

Extracted meal contains about 25-30% solvent, recovered through indirect steam heating and direct steam stripping. This process also deactivates urease, partially denatures protein, and creates a unique aroma. The meal is then dried and cooled to meet quality and storage standards.

Miscella Evaporation:

Miscella contains around 70% solvent, which is evaporated under vacuum at lower temperatures to concentrate the oil. This process uses the difference in boiling points between oil and solvent.

Miscella Stripping:

After evaporation, the miscella’s concentration reaches 95-99%. Remaining solvent is removed using steam injection, which lowers the miscella’s boiling point and releases solvent molecules from the oil.

Solvent Recovery from Free Gas: 

Free gas, mixed with solvent vapor, is collected and partially condensed to recover the solvent. Residual gases containing solvent are treated with methods like absorption towers, freezing, or paraffin oil absorption for efficient recovery.

These methods enhance efficiency, reduce residual oil, and promote environmental protection through solvent recovery, making soybean extraction equipment vital in industrial production.