Page 132 - Biofuels Refining and Performance

Raw Materials to Produce Low-Cost Biodiesel 115

conversion of triglycerides to methyl esters. Further genetic modifica-
tions must be made [71, 72]. Later studies have revealed that genetically
modified oils present relatively low viscosity that is predicted to enhance
their performance as alternative diesel fuels [73]. Also, atomization prop-
erties suggest better fuel performance, because this oil has short-chain
triglycerides, while traditional vegetable oils contain predominantly
long-chain triglycerides [74].

4.2.5 Jatropha curcas oil
Crop description. J. curcas—commonly known as pourghere, ratanjyot,
Barbados nut, physic nut, parvaranda, taua taua, tartago, saboo dam,
jarak butte, or awla—belongs to the family Euphorbiaceae and grows
in hot, dry, tropical climates (see Fig. 4.6). It originated from South
America and is now found worldwide in tropical countries. It grows wild
especially in West Africa, and is grown commercially in the Cape Verde
Islands and Malagasy Republic. The tree reaches a height of 8 m and
is a tough, drought-resistant plant that bears oil-rich seeds prolifically
under optimum growing conditions [75]. The seeds contain about 55%
oil [76]. The oil contains a toxic substance, curcasin, which has a strong
purging effect. Major fatty acid composition consists of myristic acid
(0–0.5%), palmitic acid (12–17%), stearic acid (5–6%), oleic acid
(37–63%), and linoleic acid (19–40%) [77].

Main uses. It has been cultivated as a drought-resistant plant in mar-
ginal areas to prevent soil erosion. The oil has been commercially used

Figure 4.6 Jatropha curcas. (Photo
courtesy of Piet Van Wyk and
EcoPort [www.ecoport.org].)