News Center

　　The principle of leaching oil by leaching equipment is to use organic solvents that can dissolve grease to extract the grease from the preform through the effects of wetting, penetration, and molecular diffusion, and then separate the leached mixed oil to obtain crude oil.

　　 When the leaching equipment is used to make oil, a suitable solvent is very important. The ideal solvent has practical value for improving the leaching effect, improving the quality of oil and meal, reducing costs and consumption, and ensuring production safety. Here are five types of solvents suitable for oil leaching in the production of leaching equipment.

　　1. Aliphatic hydrocarbons; currently the most widely used are n-hexane, industrial hexane and light gasoline which are liquid at room temperature. Experiments have proved that the best application is methyl pentane. In addition, propane and butane are also solvents for liquid leaching at room temperature and low pressure with good selectivity.

　　2. halogenated hydrocarbons; such as dichloromethane, dichloroethane, trichloroethylene, carbon tetrachloride, etc. The methylene chloride has a low boiling point, is non-toxic to the leaching meal, and can dissolve aflatoxin, gossypol, wax fat, etc., so it has the function of oil extraction and detoxification, but the cost is relatively high.

　　3. Aromatic hydrocarbons; mainly benzene, which is the strongest solvent in hydrocarbons. It can also leach gossypol, but the oil is dark and toxic, so it is generally not suitable for use.

　　4. Alcohols; mainly ethanol and isopropanol. This is a kind of solvent with strong polarity, which can dissolve grease at temperatures close to the boiling point. Moreover, the method of lowering the temperature can also be used to separate the solvent and grease from the mixed oil. This kind of extract that can be used for specific gravity contains more phospholipids, saponified substances, and gelatinous substances such as prolamins, flavonoids and sugars, which makes separation difficult. In the production, the azeotropic liquid of alcohol and water is often used as a solvent, which can reduce the boiling point of leaching oils, dissolve phospholipids, pigments, sugars, and aflatoxin, etc., so as to improve the quality of the separated oils.

　　 5. Other solvents; such as acetone, methyl ethyl ketone, petroleum ether, carbon disulfide, furfural and furfurone, etc.

　　In actual production, only industrial hexane or light gasoline (called No. 6 solvent in my country) are the most commonly used. This is a low boiling point fractionation product in petroleum with low boiling point. It can be miscible with most fats except castor oil in any proportion at room temperature, but it is not easy to dissolve colloidal compounds, chlorides and other non-fatty substances. . Colleagues, non-corrosive to equipment, stable chemical properties and low toxicity. But its biggest disadvantage is that it is flammable and explosive. When the content in the air reaches 1.25% to 4.9%, there is a danger of explosion. Moreover, the composition of No. 6 mineral spirits is complex and the distillation range is wide, so it is best to use industrial hexane with a narrow boiling point range.