Crude Jatropha Oil

The oil from Jatropha seeds can be extracted by two different methods; mechanical extraction using a hydraulic or screw press machine (through heating), and solvent extraction.

Mechanical:
To prepare the seeds for mechanical extraction, the seeds are solar heated for several hours or roasted for 10 minutes, without overheating. The process breaks down the cells containing the oil and eases the oil flow. The heat also liquefies the oil, which improves the extraction process. A hydraulic press machine is then used to compress a measured amount of seeds and extract the oil.

Solvent:
Solvent extraction yields the maximum seed oil, that is 38% by weight of the seed, or 99% of the total available vegetable oil. The process involves the use of two solvents, Hexane and Isopropanol, applied in varying proportions to extract oil from crushed Jatropha seeds.

The oil extracted using the solvent process can be purified by:

Sedimentation:
This is the easiest way to get clear oil, but it takes about a week until the sediment is reduced to 20-25% of the raw oil volume.

Boiling with water:
The purification process can be accelerated significantly by boiling the oil with about 20% of water. The boiling should continue until the water has completely evaporated (no bubbles of water vapour anymore). After a few hours the oil then becomes clear, separated from the seed-cake and other residue.

Research shows that the seed-cake and other residue from the extracted oil have high mineral content of nitrogen (6%), phosphorous (2, 75%) and potassium (0.94%), which can be used as organic fertilizer. An application of one ton of press cake is equivalent to 200 kg of mineral fertilizer (NPK 12:24:12).

The residual substance obtained from the sedimentation of the oil during the purification process in the tank has also industrial and commercial value. It can be mixed and boiled with caustic soda and water for raw soap production.

At 35 to 40 percent oil yield, Kimminic Corporation expects to extract and generate up to 70,000 tons of oil in 2009 growing to 227,500 tons of oil by 2013.

The oil from Jatropha seeds can be extracted by two different methods