The same as other oil seeds, there are two methods of groudnut oil extraction, one is mechanical pressing, the other is chemical pressing use solvent.
The oil content of the groundnut is between 45% and 55%. It should firstly be pretreated by professional seed cleaning equipment. Then the cleaned groundnut seeds are sent to the oil milling plant to be pressed into oil by oil presses. However, the crude groundnut oil usually contains a number of impurities. So for edible oil, the pressed groundnut oil seeds to be extracted in the oil extraction plant before sent to the oil refining plant for further groundnut oil processing.
Then oil is separated from solvent by vaporizing solvent out. In configuring the solvent extraction plant, pre-pressing may be involved in which case seeds are lightly pressed, and which leaves about 14% to 18% oil in the pressed cake. Solvent extraction will further process these cakes and leave less than 1% oil in the final cake. This method results in higher yields, more oil; Lower power consumption, lower wear & tear / maintenance and high extract efficiency. Thus it could be used as complement equipment to extract the oil remained in cake, which yields are extra profits. Certainly if the capacity is less than 50 tons, or it is high rate of output oil, this process could be saved.
