Basic principles and elements of soybean oil extraction

The extraction oil production method uses a solvent that can dissolve oil to extract the oil in the embryo through wetting penetration, molecular diffusion and convection diffusion, and then separates the mixed oil composed of solvent and fat, recovers the solvent to obtain crude oil, and also recovers the solvent in the oilseed meal to obtain the extracted meal. In this process, the basic elements are the solvent and the embryo, as well as the extraction method and process parameters that determine the extraction effect.
1. Selection of solvent
The ideal extraction solvent should meet the following basic requirements:
① It can dissolve oil in any proportion at room temperature or low temperature;
② The selectivity of the solvent should be good, that is, it does not dissolve other components except oil.
③ Stable chemical properties, stable to light and water, no chemical changes after heating, evaporation and cooling.
④ The solvent is required to have a low boiling point, low specific heat and low latent heat of vaporization, and easy to separate and recover from meal and oil.
⑤ The solvent itself is non-toxic, neutral, odorless and non-polluting.
⑥ The solvent does not react chemically with oil, meal and equipment materials. The most commonly used leaching solvents in the actual production of my country's oil industry are several aliphatic hydrocarbons such as industrial hexane or light gasoline. Among them, light gasoline is the most widely used solvent in my country. It is a low-boiling point fractionation product of petroleum raw materials and meets the above basic requirements of solvents. But the biggest disadvantage is that it is flammable and explosive. When the content in the air reaches 1.25-4.9%, there is a risk of explosion. At the same time, light gasoline has a complex composition and a wide boiling point range. In addition, acetone, butanone, isopropanol, butane and some composite solvents can be used for oil leaching, and some have been studied and tried.
For some oil crops with high oil content, such as soybeans, the oil yield of the pressing method is generally around 10% - 20%, while the oil yield of the extraction method can reach around 20% - 30%; for oil crops such as rapeseed, the extraction method can also significantly increase the oil yield compared to the pressing method, and can make more full use of oil resources.
Good quality of meal
1. Nutrient preservation
During the extraction process, since organic solvents are used to separate the oil, the damage to nutrients such as protein and cellulose in the oil is relatively small. The resulting meal can be used as a high-quality feed raw material with high protein content and good quality.
2. Suitable for a variety of uses
For example, soybean extraction meal is rich in protein and can be widely used in animal husbandry and aquaculture industries to provide animals with rich nutrition. In addition, the color, smell and other quality indicators of the meal are good, which is conducive to improving the overall quality of the feed.
Low processing cost
1. High production efficiency
The process of oil production by extraction is relatively short and the production speed is fast. In large-scale industrial production, a large amount of oil crops can be processed in a shorter time, which improves production efficiency.
2.​Solvents can be recycled
The organic solvents used can be recovered and recycled through evaporation, condensation and other processes after oil extraction. This not only reduces the cost of solvent consumption, but also reduces the pollution caused by solvent emissions to the environment, and also meets the requirements of sustainable development.
Huatai Group is a large soybean oil machine manufacturer, soybean oil processing machinery equipment supplier, any need please email to info01@cnoilmachine.com