Solvent extraction refers to the process of extracting oil from oil bearing materials by means of a solvent or chemical way. The cakes after the first pressing could also be used as raw materials for a solvent extraction plant.
Solvent extraction oil has adopted a leaching process to get vegetable oil. The extraction principle is the theoretical basis of the leaching process. The leaching process originates from France in 1843 with the healthy, safe and advanced technology. In modern time, the developed industrial country gets more than 90% of the edible oil through the extraction method.
The process of extracting vegetable oil from oilseeds is not very complex. Take a look at the steps:
1. The seeds are husked and cleaned of dirt and dust, then crushed.
2. Before the oil extraction process, the crushed seeds should be heated to temperatures between 110 degrees and 180 degrees.
3. The seeds are put into a high volume press which uses high heat and friction to press the oil from the seed pulp.
4. The seed pulp and oil are then put through a hexane solvent bath and steamed again to squeeze out more oil.
Note: Hexane is produced by the refining of crude oil. It is a mild anesthetic. Inhalation of high concentrations produces first a state of mild euphoria, followed by sleepiness with headaches and nausea. Chronic intoxication from hexane has been observed in recreational solvent abusers and in workers in the shoe manufacturing, furniture restoration and automobile construction industries where hexane is used as glue. The initial symptoms are tingling and cramps in the arms and legs, followed by general muscular weakness. In severe cases, atrophy of the skeletal muscles is observed, along with a loss of coordination and problems of vision. In 2001, the US Environmental Protection Agency issued regulations on the control of emissions of hexane gas due to its potential carcinogenic properties and environmental concerns.
5. In a centrifuge, the mixture of seed and oil is added phosphate to separate the oil and seed residues.
6. After solvent extraction, the crude oil is separated and the solvent is evaporated, recycled and recovered. The seed pulp residues are conditioned and reprocessed to make the by-products such as animal feed.
7. The last process is refining. The further refining techniques are composed of degumming, neutralization, and bleaching.
The machine produced by Amisy is with a simple design, strong function as well as flexible operation. With more than thirty years of experience, Amisy has made a big difference in the field of oil press machine.
The plant is designed to extract oil from oilseeds whose oil containing rate is below 20%, such as sunflower, peanuts, cottonseed, palm kernel, canola, copra, castor, and various other materials.
Based on the competitive advantages in both structure and utilization, edible oil extraction technology has become the most advanced production technology in the international edible oil processing field.