For oil seeds with relatively low oil content, like rice bran, the function of direct squeezing method for oil extraction is limited. Thus, rice bran oil plants often use puffing solvent extraction methods to extract rice bran oil, that is, the rice bran is puffed into loose and porous particles and then use the solvent extraction methods to extract the rice bran oil.
The main processing sections of rice bran oil puffing solvent extraction process consists of four systems: solvent extraction system, wet meal desolventizing system, mixed oil evaporation system, and solvent condensation recovery system, that is, immersing rice bran raw materials into n-hexane to extract the rice bran oil and removed the wet meal and the solvent, finally obtain the crude solvent rice bran oil.
The detailed process are as follows:
1 Rice bran oil extraction
In the rice bran oil solvent extraction system, people usually immerses the rice bran in n-hexane solution to extract rice bran oil and get the mixed oil and wet meal.
2 Remove the leaching solvent in the wet meal
Separate the wet meal from the mixed solution and remove the leaching solvent by using desolventizing toasting drying and cooling tower (D.T.D.C) to desolventizing, toasting, dry and cool the mixed oil in the evaporated wet meal, and the dry meal will be used as animal feed or fuel.
3 Crude oil and solvent separation by evaporating
The mixed oil evaporation system has three main equipment: the first long tube evaporator, the second long tube evaporator and the stripper. After being treated, the solvent in the mixed oil is evaporated and enters the solvent condensation recovery system, so that we can get the individual crude rice bran oil and the solvent.
4 Solvent condensation recovery
Mixed oil evaporation system passes through the condenser, and then solvent is recovered and stored for reuse, dry meal will be treated as animal food.
The task of rice bran oil solvent extraction is completed when you get the crude oil of rice bran leaching.