Jatropha – Green Biodiesel from African Tree
by Bård Amundsen/Else Lie. Translation: Darren McKellep/Carol B. Eckmann(The Research Council of Norway) Jatropha has been championed as a major environmental opportunity for developing countries with a semi-arid climate and marginal soil. Scientist Karl Hilding Thunes of the Norwegian Forest and Landscape Institute has been investigating whether this small, hardy and relatively pest-free tree lives up to its billing. The project is partly financed by the Research Council of Norway’s Norway – Global Partnerprogramme (NORGLOBAL).
Biofuel of the future
Jatropha is a top candidate for future large-scale biodiesel production, according to investment bank Goldman Sachs. TIME Magazine reported that jatropha could yield 6 tonnes of biodiesel per acre (15 tonnes per hectare) annually. The New York Times wrote that this otherwise worthless weed far eclipses corn’s efficiency as a biofuel.
Furthermore, since it can grow in soils and climates poorly suited for cultivating edible crops, jatropha poses little threat to food production in developing countries.
A few years ago, a Stavanger-based company secured the rights to cultivate jatropha in Ghana on a tract of land nearly twice the size of Luxembourg. The ambitious plan is to eventually produce 20 000 barrels of oil per day, which would make the company Norway’s second-largest oil producer, behind Statoil. Other international companies have permits to grow jatropha at a number of sites around Africa.
“Jatropha has undoubtedly been over-hyped somewhat in recent years. Expectations have become more realistic now, but there is no question that jatropha has major potential,” asserts Dr Thunes.
The scientist has conducted studies and field trials with jatropha in Ghana and Niger. He has surveyed the pest risk factors that threaten jatropha crops, and studied how to cultivate the tree in order to minimise pest problems and prevent mass invasion.
Robust in dry heat
“Jatropha is indeed a hardy tree that thrives in hot, dry climates,” explains Dr Thunes. “But it is not as invincible as some people have trumpeted.”
“It’s true that jatropha does well in quite extreme conditions, but in order to yield plenty of fruit for producing oil, it needs sufficient water, fertiliser and care.
…Producing any biofuel crop, however, whether sugar cane, corn or jatropha, requires large volumes of water and fertiliser – a fact that diminishes the environmental benefit. Jatropha can be fertilised with its nutrient-rich press cake (a residue of the oil extraction process) and survives on far less water compared to sugar cane and corn.
Throughout Africa, in places without electricity, jatropha also represents opportunities for localised oil production for running small, local power-generating plants. READ MORE