Jatropha oil is hydroscopic. Jatropha oil absorbs water and needs nitrogen blanketing in steel tanks. We are learning more and more about the properties of Jatropha. One issue that is quite clear is that, because Jatropha is high in acid, Jatropha oil has the tendency to degrade quickly, particularly if not handled properly through the supply chain.
Right from the time of expelling, the oil needs to be kept in storage conditions that prevent undue degradation. Exposure to air and moisture must be minimized, hence the need for nitrogen blanket in the tanks.
The range of fatty acids present in various seeds will differ but the oil and biodiesel that is produced must be acceptable. However, this assumes that oil is fully degummed. The degumming may well be more of a problem than making biodiesel!
The phospholipid, protein and phorbol ester contents in edible Jatropha seem to be quite different to non-edible. It needs to determined if this affects the degumming method. The degumming removes lecithin and other related compounds, so if these are high, then a modified degumming method may be needed.
If the oil is properly dried after degumming and kept under nitrogen blanketing. This may suffice. Bio diesel companies are investigating storage requirements and oxidative stability of Jatropha.
Seeds degrade as soon as they are picked and so careful storage and handling is required. In the warm humid atmosphere, the degradation of seeds can be rapid. Even in the cold countries, seeds storage is a problem. Recently an importer had samples of rape seeds, that had been harvested and stored in wet weather. The analysis showed that they had 28% of free fatty acid! They had a strong smell from the yeasts that were growing on the seeds.
Hence at temperature of >30^oC the problems can be greater. Since the JC seeds are toxic, attack by animals and rodents is unlikely to be a problem.
Rubber Nitrile tanks are perfect for container shipping, as there is no exposure to the atmosphere or the air, this is because it is collapsible and always works in a vacuum. These can be fitted in a 20 feet, 30 ton container. Each container would hold about 22.4 tons Jatropha Curcas crude oil. Indian suppliers of these rubber tanks have been identified.