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Turning Seaweed into the Fuel of the Future

Could seaweed farming prove a boon for biofuels?
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ISTOCKPHOTO/LESLEYJACQUES

Seaweed holds promise as more than an ingredient in a purifying face mask or a maki roll.

So say researchers at E.I. du Pont de Nemours & Co., which alongside Seattle-based Bio Architecture Lab (BAL) has secured $9 million from the Department of Energy to explore seaweed's potential as a feedstock for biobutanol, an advanced biofuel.

Their venture appears to have largely cornered the current market. Though more than 200 companies have looked into algae-based biofuels, DuPont and BAL say most others have shied away from using macroalgae, like kelp.

"We're in the vanguard here on this technology. There are other people who have talked about changing microalgae -- green algae that floats in the water -- into advanced biofuel, but [using] seaweed is unique," said DuPont's Nathan Danielson, a program manager who oversaw the companies' DOE grant application.

That's why the companies were able to win one of DOE's Advanced Research Projects Agency-Energy (ARPA-E) awards, announced late last month, which are designed specifically for ambitious "high-risk, high-payoff" energy research projects.

Part of the reason seaweed hasn't taken off as a biofuel source is that it's not part of American culture, said Nikesh Parekh, CEO of Bio Architecture Lab. "Our founders are from Japan, and they are much more familiar with seaweed farming and seaweed as a culture crop."

Planting a large-scale seaweed farm would likely come up against stiff opposition from those who are not used to seaweed farms in their backyards, agreed Mike Graham, an ecologist specializing in seaweed at the California State University-associated Moss Landing Marine Laboratories.



Difficulty controlling seaweed probably also kept interested companies focused on the more manageable microalgae, since it's so small, Graham said. A startup could more easily select a preferred strain of algae, grow it in a man-made pond on land, and oversee the process, he said. Of course, the downside to that, says BAL, is that it can be a costly endeavor.

Aquafarming

Most U.S. seaweed operations, like Maine Seaweed Co., harvest a fraction of the hundreds of thousands of tons of seaweed naturally available along the U.S. coast, but BAL hopes to farm its own.

Parekh says his company, which is in charge of growing seaweed for its biobutanol project, is interested in farming the seaweed because it is more environmentally sustainable.

"One of the challenges of harvesting a natural seaweed bed is you can only do a certain percent of the bed if you don't want to have a negative environmental impact," he said. "The economics of production suggest that we'll be better off if we grow our own seaweed and locate it close to our plant."

But to farm enough seaweed to support mass production of a biofuel would be a large departure from current U.S. practices.

Graham has one of the few seaweed farms in the United States -- perhaps the largest -- and he only grows about a ton of seaweed a year to augment abalone snails' diet.

If successful, though, the payoff could be well worth it. Biobutanol advocates, including DuPont, say the fuel could work better in automobiles than the better-known ethanol and will be easier to transport.

The key to unleashing seaweed's biobutanol potential is in a BAL-designed microbe that lives entirely off of seaweed as a carbon source, the company says.



"We were really the first to think of that," Parekh said. The microbe takes sugar from the seaweed and thus far can produce ethanol as a byproduct.

The company plans to work with genetic engineers at DuPont to further perfect the microbe -- programming it to produce biobutanol.

'It can look easy on paper'

The other piece of the puzzle is that biobutanol is really an experimental biofuel itself. DuPont says it has already succeeded at extracting sugar from corn and converting it into biobutanol in the lab, but it has yet to scale up the operation.

The company will not disclose how much butanol it expects to produce from seaweed, citing competitive reasons.

Parekh says that the companies believe they will one day be "competitive" with petroleum, and as a bonus, they will be able to avoid the steep up-front costs microalgae farmers face to create pools for their algae.

BAL could theoretically just lease some offshore areas from the government and farm the seaweed there. The company, which also has a site in Chile, is still considering locations in both the United States and abroad as potential farm destinations. The site selection will also determine its seaweed of choice, since it hopes to grow seaweed that is native to its surroundings.

DuPont estimates that if just 2.5 percent of America's coastline were used for seaweed growth -- all along the continental shelf in those areas -- 6.8 billion gallons of fuel could be produced per year.

The companies maintain that they do not see seaweed as better than other types of algae, just as another biofuel option. "We can't get ourselves over the capital hurdle around microalgae yet, but we're really watching both areas," DuPont's Danielson said.

The companies plan to start work with the seaweed in early 2010 and work on the early stages of the project over the next two years while funded by the ARPA-E grant. Though they don't expect the product will be close to market-ready at that time, they hope to better gauge whether it will be feasible to continue research on this track.

"With R&D, it can look easy on paper," Parekh said, "but you can run into all sorts of challenges."

Reprinted from Greenwire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500

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