In Mali, this machine can turn the local nut into fuel.

The New York Times had an article today about growing Jatropha curcas in Mali for use as biofuel, Mali’s farmers discover a weed’s potential power.

. . . jatropha is being hailed by scientists and policy makers as a potentially ideal source of biofuel, a plant that can grow in marginal soil or beside food crops, that does not require a lot of fertilizer and yields many times as much biofuel per acre planted as corn and many other potential biofuels. By planting a row of jatropha for every seven rows of regular crops, Mr. Banani could double his income on the field in the first year and lose none of his usual yield from his field.

Poor farmers living on a wide band of land on both sides of the equator are planting it on millions of acres, hoping to turn their rockiest, most unproductive fields into a biofuel boom. They are spurred on by big oil companies like BP and the British biofuel giant D1 Oils, which are investing millions of dollars in jatropha cultivation.
. . .
But here in Mali, one of the poorest nations on earth, a number of small-scale projects aimed at solving local problems — the lack of electricity and rural poverty — are blossoming across the country to use the existing supply of jatropha to fuel specially modified generators in villages far off the electrical grid.

“We are focused on solving our own energy problems and reducing poverty,” said Aboubacar Samaké, director of a government project aimed at promoting renewable energy.

If jatropha can be grown in conjunction with food crops, as the article implies, in a manner that actually facilitates local development, that would be a great boon. The article also describes huge plantations of jatropha for biofuel:

Countries like India, China, the Philippines and Malaysia are starting huge plantations, betting that jatropha will help them to become more energy independent and even export biofuel.
. . . farmers in India are already expressing frustration that after being encouraged to plant huge swaths of the bush they have found no buyers for the seeds. (And who paid for the seeds for the crop, and to put the land into cultivation? Are these farmers now in debt based on someone else’s speculation?)

For more information on the jatropha plant in Africa there is an article here from a biofuel corporation. And another document with a bit more information about some of the questions, and about storing and processing here: PDF: Jatropha investment in Africa:

. . . biofuel has been accused of having a negative energy payback . . . but there is great variation in the energy paybacks for various biofuels.
Jatropha is a perennial, yielding oil seed for decades after planting, and it can grow without irrigation in arid conditions where corn and sugar cane could never thrive.
. . . the oil . . . burns without emitting smoke.

As the pdf document points out, jatropha needs to be handled and processed quickly, with attention to certain factors such as guarding it from moisture, or the product will be damaged and degraded, and not necessarily usable. Some of the questions about its practicality have not been resolved.

Added April 2008: I crossed out the lines above because the link is dead. I found some information about the processing in another location. This article is about 3 years old, and is rather naively optimistic about jatropha’s potential yields, but it does contain some general information that is useful to know about processing jatropha.

From Jatropha in Africa:

1) Jatropha oil is hydroscopic – absorbs water and needs nitrogen blanketing on steel tanks. One issue that is quite clear is because Jatropha is high in acid, it has the tendency to degrade quickly, particularly if not handled properly through the supply chain.

2) 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 blanketing on the tanks.
. . .
Seeds degrade as soon as they are picked and so careful storage and handling is required. In the warm humid atmosphere in countries such as Ghana the degradation of seeds can be rapid. (end 2008 addition)

Other things I’ve been reading lately may or may not be relevant to this issue.

Increasing atmospheric carbon dioxide levels could change the nature of grasslands and decrease their usefulness as grazing pastures, say researchers . . . Woody shrubs . . . thrived.
. . .
The main reason why these woody shrubs out-compete grasses in conditions of high carbon dioxide, says Morgan, is because their method of photosynthesis is better suited to high levels of the gas.

The major concern, he says, is that woody shrubs . . . are unpalatable to most domestic livestock, so domination by these types of plants would render land poor for grazing.

. . . there is already evidence of shrub encroachment in many grasslands of the world.

Jatropha is a woody shrub and might be advantaged by this climate change. I’m not sure what the implications are for food or fuel, though I can guess at a few. There are some suggestions on how to control this change:

. . . a possible way to lessen the transformation of grasslands is to use controlled burning, which kills shrubs but not grasses, and to prevent overgrazing, which weakens grasses and allows woody plants to move in.

I think the question to ask about jatropha is, does the crop provide direct advantage to the local farmers and their community rather than promising some trickle down advantage later, a promised advantage that will likely never arrive. And, are the farmers still able to feed themselves and their communities, and profit from growing food?