How to choose between direct solvent extraction process and pre-press solvent extraction process?

The edible oil extraction process is a kind of oil production process that applies the principle of solid-liquid extraction, chooses a certain organic solvent that can dissolve oil - n-hexane, and extracts the oil from the oil through spraying and soaking the oil. It is a stable, hygienic, scientific and excellent oil production process recognized by the world. Compared with the traditional pressing process, this process has the characteristics of less residual oil in the meal cake, high oil yield, low processing cost, high economic benefit, high meal quality and good feeding effect. Choosing the right extraction process is crucial to optimize edible oil production and maintain product quality.

Direct solvent extraction is a method in which the seeds are completely immersed in a solvent (usually n-hexane) to extract the oil. The process is efficient and achieves higher oil yields compared to other methods. Key advantages include high extraction efficiency and low residual oil content in the meal. However, it also involves higher operating costs and requires complex equipment to safely manage the solvent.

Direct solvent extraction machines

Pre-press solvent extraction involves two stages: initial mechanical pressing of the seeds, followed by solvent extraction of the remaining oil. This method is favored for its ability to reduce solvent consumption and minimize equipment wear. While oil yields may be lower than direct extraction, pre-press allows for easier meal handling and generally produces a more desirable product quality.

Pre-press solvent extraction machines

Selection based on raw material variety

Different types of raw materials have different oil contents. For example, peanuts, rapeseed, sunflower seeds and other oils have high oil contents. For such high-oil-content oils, the direct solvent extraction process will result in a high residual oil rate in the meal, resulting in oil waste. Therefore, the pre-pressing-extraction process can be used to extract oil in production. For oils with low oil content, such as soybeans and rice bran, the direct solvent extraction process is suitable. This process simplifies the production process and improves processing efficiency.

Comparing Oil Yield and Quality

When evaluating these two processes, consider the trade-off between oil yield and product quality. Direct solvent extraction generally yields more oil, but may affect the flavor and color of the final product. In contrast, pre-press solvent extraction may yield slightly lower yields, but generally retains better flavor and nutritional value in the oil.

Cost Considerations

From the perspective of overall investment, the pre-press solvent extraction process may have a slightly higher investment cost for the same processing volume due to the larger number of equipment. From the perspective of equipment cost analysis, if the budget is low, the direct solvent extraction process can be considered.

Production scale and flexibility

The scale of your operation will also influence the decision. Direct solvent extraction is suitable for large-scale production, where maximizing yield is critical. Pre-pressed solvent extraction offers greater flexibility for small to medium-sized operations, allowing adjustments based on market demand and product specifications.

In summary, the choice between direct solvent extraction machines and pre-press solvent extraction machines depends on your specific needs, including desired oil yield, cost considerations, and production scale. Evaluating these factors will guide you in selecting the method that best suits your edible oil processing, ensuring your operational efficiency and product quality. If you want to know more about our equipment, please feel free to contact us, we will serve you wholeheartedly!