Jatropha oil can be extracted from the seeds in three ways:
The following illustration describes the oil extraction process of from Jatropha seeds
Below most common methods for oil extraction from Jatropha seeds are introduced
Oil presses method is used to extract the oil using simple mechanical devices. It is also done manually. The most commonly used oil presses method is the Bielenberg ram press method.
Bielenberg ram press method is a simple traditional method that uses simple devices to extract the oils. With the help of this method 3 liters of oil can be obtained with 12 kg of seeds.
Oil expellers method is also use for jatropha oil extraction. The most commonly used method is the Sayari oil expeller method. This method is also called as Sundhara oil expeller. Komet oil expellers are also used.
These sayari oil expellers was developed in Nepal and is a diesel operated one. Now it is developed in Tanzania and Zimbabwe mainly for the production jatropha oil. Heavy oil expellers are made of heavy cast iron and the light ones are made up of iron sheets. Electricity driven models are also available.
Komet oil expeller is a single oil expeller machine that is used not only to extract the jatropha oil as well for the preparation of the oil cakes.
Traditional methods are used in the rural and developing areas for extracting the oils. Traditional methods are simple and the oil is extracted by hand using simple equipment.
Hot oil extraction
The process of extracting the oil at high pressure is called as hot oil extraction method. Since jatropha oil can regulate the operating temperature it is extracted using the hot oil extraction method.
Then the cold oil extraction method it is easy to extract the oil from the hot oil extraction since the oil flows more easily due to higher viscosity. And the press cake that remains after extracting the oil also have less oil content which might be 3 to 7 % approximately. These two reasons make the oil press method very interesting.
During the oil extraction method many stuffing of the seeds are converted into gum like substances and some non organic substances. These are unwanted products and so they have to be refined.
More modern methods allow extracting even higher oil quantities from Jatropha seeds. In these advanced concepts, also chemical techniques like aqueous enzymatic treatments are applied. In turn, the yield averages 10-20% above traditional proceedings.