August 14, 2007 – Vol.12 No. 21
JATROPHA CURCAS: PROMISING BIOFUEL FEEDSTOCK OR INVASIVE SPECIES?
Generally speaking, transplanting a species from one part of the world to another - either accidentally or on purpose - has, on occasion, had some really negative consequences. A prime example is kudzu that was moved from Asia to the southeast US beginning in the 1930’s to control erosion. It did that but now kudzu overgrows just about everything in its path and is almost impossible to get rid of.
Now, with the push to find alternative and renewable sources of fuel in the US and elsewhere, oil from the seeds from a shrub called Jatropha Curcas has arisen as a very good source of biodiesel. But it’s not a native plant to every corner of the Earth; thus if it is transplanted in say South Carolina or Iowa (places where it may not be found today) would it become an invasive species? What would be the impacts, the consequences, of farming Jatropha curcas on a large scale? (It’s already classified in Western Australia as an invasive species and its use in biodiesel production is banned.)
Here’s a short list of what we know about Jatropha curcas:
--- It’s a shrub whose oily seeds or nuts are also called Barbados or Physic nut; Jatropha curcas belongs to the Euphorbiaceae or spurge family. Curcas is one member of the Jatropha genus, of which there are about 175 members;
--- It’s considered poisonous (to some degree,) as its seeds or nuts, and oil from them are non-edible;
--- Its origins are thought to be Central America, or perhaps the Caribbean, but it is now grown in Asia and Africa and elsewhere.
--- It doesn’t need much water to survive - only about 10 inches (250 mm) of rainfall per year - thus can be grown in arid regions and will grow well on marginal land;
--- Once growing, it has a long life, about 40-50 years and needs little maintenance; it doesn’t have to be plowed under each year;
--- It can stop land degradation and reverse deforestation;
--- It can be grown alongside food crops and won’t compete;
--- As a perennial (doesn’t die every year) it can sequester carbon too. A full grown shrub or tree absorbs around 18 pounds (8 kilograms) of carbon dioxide every year. 2500 shrubs can be planted in a hectare (about 2.5 acres), resulting in more than 20 tons of greenhouse gas sequestration per year.
As a feed stock for biodiesel fuel it holds considerable promise as well:
--- Each hectare can produce an average of 500 gallons (1900 liters) of biodiesel per year from its nuts as well as more than 7500 lbs (3400 kilograms) of waste biomass. For biodiesel, Jatropha yields more than four times as much fuel per hectare as soybean; more than ten times that of corn;
--- Alternatively the entire seed (unsqueezed for oil) can be used in digesters for biogas production;
--- The “cakes” remaining after the seeds are pressed for oil can be used as feedstock for digesters to produce a biogas for cooking or power generation, or alternatively the cakes can be used as fertilizer;
--- Jatropha curcas converted to biodiesel has already been tested in vehicles.
Aside from fuel or fertilizer, Jatropha also has some medicinal qualities:
--- Extracts have also been shown to have anti-tumor activity;
--- Wounds can be dressed with the sap from it and the leaves can be boiled to obtain a malaria and fever remedy;
--- The seeds can be used as a remedy for constipation, if that’s a problem.
Large scale Jatropha plantations are being created in India, China, Burma, Nicaragua, Africa, the Philippines and Brazil where the first commercial Jatropha biodiesel is set to begin operation.
Using a processing unit from BioDiesel Technologies, the plant operator, Compahnhia Productora de Biodiesel de Tocantins will have the ability to produce 40,000 tons per year of biodiesel made from Jatropha and animal tallow.
A 48,000 hectares of Jatropha plantation as been established to supply feedstock to the operation.
BioDiesel Technologies of Vienna, Austria builds modular, medium-scale biodiesel processing equipment that can be set up and in operation in 1-3 days. The unit fits inside a standard shipping container and will operate on a variety of feedstocks.
All of this sounds promising, does’t it? The world has been bitten many times before by invasive species, it probably should be careful with Jatropha.
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