The most commonly used edible oil extraction methods in oil mill plant mainly include pressing method, solvent extraction method and pre-pressing solvent extraction method. These three methods have their own characteristics and are suitable for different raw materials and production requirements.

Pressing method

Pressing is a traditional oil extraction method. It squeezes the oilseeds through mechanical equipment to separate the oil from it. This method is simple to operate, does not need complicated chemical treatment, and has high oil quality and retains the natural flavor of raw materials. However, the oil yield of pressing method is relatively low, which is suitable for some raw materials with high oil content, such as peanuts and sesame seeds.

Solvent extraction method

Solvent extraction is a modern oil extraction method. This method uses organic solvents (such as n-hexane) to extract oil from oilseeds, dissolving the oil in the solvent. The solvent is then recovered through evaporation and separation to obtain edible oil. This method offers high oil yield and is suitable for large-scale industrial production. However, due to the use of chemical solvents, it requires strict equipment and process control, and necessitates rigorous handling of residual solvents to ensure food safety.

Pre-pressing solvent extraction method

Pre-pressing solvent extraction method combines the advantages of pressing and solvent extraction. It first extracts a portion of the oil through pressing, and then further extracts the remaining oil through solvent extraction. This method increases oil yield while reducing solvent usage, and is widely used in processing raw materials with low oil content, such as soybeans and rapeseed.

In a word, these three edible oil extraction methods are often selected and combined according to the characteristics of raw materials, equipment conditions and market demand in actual production, so as to achieve the balance between economic benefits and product quality.