Seed oil can be extracted either hydraulically using a press or chemically using solvents. Chemical extraction can only be achieved in large industrial plants. Several types of mechanical equipment are available: screw presses (hand-or engine — powered), spindle presses, and hydraulic presses, which are distributed widely throughout developing countries for the extraction of seed oils for nutrition pur­poses. Hydraulic presses are widely used in Ghana, West Africa.

Take a country like Ethiopia, one of the poorest countries in Africa. The country spends yearly $800 million in oil imports, and could become completely self­sufficient in energy if it could attract sufficient capital and investors to cultivate Jatropha and castor.

3.1.11

Biokerosene

Another development is the hydrogenation of Jatropha crude oil to produce bio jet fuel or biokerosene. Basically, this process requires the extraction of oxygen and the addition of 30 kg hydrogen per tonne of Jatropha crude oil in order to lower the freezing point to —60°C and still be liquid. Chapter 17 deals exten­sively with biokerosene.

3.1.12