You take your Jetta TDI to the gas station and fill up on diesel, and then are sent reeling by the price — $1.40 a gallon. And while you’re trying to figure out why it was so cheap, the attendant blows your mind by telling you it was made not from ancient fossilized plants but from a seed plant grown now — jatropha. What? But the Jetta runs well on the stuff, and that’s all you really need to know.

This scenario is not a complete fantasy. Air New Zealand, Japan Airlines, Continental and Mexico’s Interjet have all flown planes on a fuel that’s 48 percent jatropha, though the price at the pump will probably be higher once the government starts taxing it. SG (“Super Green”) Biofuels is a San Diego-based company that claims it can make jatropha diesel (indistinguishable from the fossil fuel version) at the equivalent of $50 a barrel. “The economics work today,” said President and CEO Kirk Haney.  

Dr. Rudolph Diesel intended to produce his very first engine on vegetable oil in 1885, so there's ample precedent for this.

Jatropha is a fast-growing tropical plant that grows six to eight feet high, and it’s mainly used south of the border for cattle fencing (cows won’t eat it because of high latex content). There’s nothing all that high-tech about fuel production from plants like this: Peel off the fruit’s outer layers and what you get is three seeds that are about 40 percent oil. When pressed in a simple mechanical process, the seeds yield a base crude that can be easily transformed into diesel. And not just any diesel — it’s a green version with 70 percent lower emissions. And it blends well with existing diesel, too.

According to Dr. Robert Schmidt, SG’s chief scientist, jatropha could also processed into gasoline, but that would require extra steps. “It’s much easier to create diesel,” he said.

The company’s version of jatropha, J Max 100, is not genetically engineered, but instead selectively bred to produce a plant with a lot of fruit. “I worked on maize for 23 years,” Schmidt said, “but I’m excited by what we can do with jatropha because we’re on the ground floor of a crop domestication improvement program for it.”

SG has amassed what is likely to be the largest world collection of germ plasma for jatropha, collected from various locations in Central America and Mexico. There are 12,000 genotypes, and SG is trying to find and breed the best of them. “This is a tried-and-true method of crop improvement,” Schmidt said.

Craig Venter’s Synthetic Genomics has sequenced the jatropha genome, which helps in SG’s work. Remember when I said that jatropha is a tropical plant? That’s an issue here, because you can’t simply replace fields growing corn for ethanol with more cost-effective jatropha (which has the added benefit of not stoking the food vs. fuel wars). Haney says that SG is talking about growing jatropha in India, which has 100 million acres of marginal land. Production costs would be low, but transportation costs high. But more than half our liquid fuel comes from halfway around the world now.

Politics are the main reason we may not see jatropha diesel at pumps around the U.S.A. It’s not grown here, so it doesn’t have the built-in support from Midwestern congressional delegations that ethanol has. It is, in fact, a “foreign fuel.” Of course, we could grow it in Florida (possibly replacing marginal and environmentally damaging sugar plantations?) or in Hawaii, where it could also replace sugar.

Jatropha is on its way. Some 5 million acres are planted worldwide. In addition to SG, players include Australia’s Mission NewEnergy, which is distributing fuel in Europe and launching in the U.S. D1 Oils is working with mega-company Siemens to power turbines on a high-speed ferry.

They seem to like the idea of using jatropha in planes. Boeing funded a study by the Yale School of Environmental Studies, released in March, which projected a 60 percent emissions reduction compared to petroleum-based jet fuel. “Jatropha can deliver strong environmental and socio-economic benefits,” it said.

Here's how Air New Zealand's jatropha test flight looks on video:

MNN homepage photo: tonrulkens/Flickr

Jim Motavalli ( @jmotavalli ) writes about cars, technology and the environmental world to anyone curious enough to ask.

Low-emission diesel from seeds at just $1.40 a gallon
Politically, it would help if we could grow tropical jatropha in the U.S., but this could be an imported fuel we'll welcome at the pumps.