A promising biofuel
The Dom Post reports on Jatropha:
Jatropha is widely viewed as the perfect biodiesel crop because it is pest and drought resistant. Jatropha trees are productive for 30 to 40 years, grow up to 3 metres high and can be grown on challenging arid land so do not compete with food crops.
It needs at least 600 millimetres of rain annually to thrive, but can survive three years of drought by dropping its leaves. More than 800 million hectares of arid and non-arable land around the world is suitable for plantations.
Seeds in the first year after planting. After five years typical annual yield of a single tree is 3.5 kilograms of beans. Oil pressed from 4kg of seeds needed to make 1 litre of biodiesel 1 hectare should yield an average 2.5 tonnes of oil.
In India, where it is widely used as biodiesel to run motor vehicles, the average cost of 1kg of seeds is 6 rupees (NZ2 cents). Refining jatropha oil into biodiesel costs less than NZ$216 per tonne.
The part that I care most about is:
Only a few years ago biofuels were regarded as uneconomical for aviation because they froze at the low temperatures encountered at cruise altitudes.
However, testing has shown that jatropha has an even lower freezing point than current jet fuel.
Personally I prefer my plane’s fuel supply not to freeze in mid flight!