Generally speaking, the main purpose of castor seed solvent extraction plant is to remove most of the oil contained in castor seeds. Usually the extraction process is being conducted on well prepared seeds or high oil content seeds, such as castor seeds, peanut, rape seeds, sunflower seeds etc.
Castor seed is grown commercially on plantations but also harvested from wild plants. The seed must be hulled after harvesting. This can be done laboriously by hand or, more commonly, by machine，in this case，small-scale hand-operated dehullers are available.
Castor Seed Solvent Extraction Plant
Extraction of oil from castor seeds is done in a manner similar to that for most other oil seeds. The ripe seeds are allowed to dry, when they split open and discharge the seeds. These seeds are cleaned, cooked and dried prior to extraction. Cooking is done to coagulate protein (necessary to permit efficient extraction), and to free the oil for efficient pressing.
The first stage of oil extraction is pre-pressing, using a high pressure continuous screw press – called the expeller. Extracted oil is filtered, and the material removed from the oil is fed back into the stream along with fresh material. Material finally discharged from the press, called cake, contains 8 to 10 percent oil. It is crushed into a coarse meal, and subjected to solvent extraction with hexane.
