2011-07-06

Co.Exist

Not Just For Sushi: Seaweed May Power The Next Generation Of Biofuels

Biofuels are taking off, but if they keep being made from corn, the world will go hungry. The oceans, full of fast-growing kelp, are the next frontier of plant-based fuel.

You've been filling up your car with corn, beats and sugar cane. Why not kelp? New research finds that summer kelp, rich with energy-dense carbohydrates and soluble sugars, may offer a new source of biofuel. While most bioenergy efforts have focused on terrestrial plants, marine ecosystems are a virtually untapped resource that represents a significant fraction of the world's biomass.

Researcher Jessica Adams at Aberystwyth University sampled the chemical composition of kelp forests in the U.K., finding that summer conditions boosted energy yields from fermentation (ethanol), anaerobic digestion (methane) or pyrolysis (bio-oil). Her research, she said, suggests "seaweed biofuel could be very important in future energy production" at a meeting of the Society for Experimental Biology in Scotland.

The need for sustainable biofuel is acute: diverting crops such as corn from plates to biofuel refineries drove up the price of food worldwide forcing an additional 100 million into chronic hunger. Beyond this humanitarian crisis, it's also an energy challenge. There is simply not enough food and fuel to substantially lower prices given mandates for European and U.S. biofuel consumption and razor thin crop surpluses. We have little choice but to find new biofuel feedstocks (or cut back altogether), or else decide that millions in the developing world will face hunger so those in the industralized world can substitute biofuels for petroleum.

That's what makes marine plants so attractive. Since seaweed and algae hold the promise of scaling biofuel production without gobbling up food crops or arable land, it's perhaps the only feedstock that can satisfy the world's demand for transportation fuels. Kelp is a good prospect. The prolific plant--a more efficient photosynthesiser than land-based plants, like most seaweed--can grow a foot per week, and already covers vast areas of ocean bottom from Ecuador to Iceland.

The market isn't waiting for full commercial production to begin burning biofuels. Airlines, pressured by European governments to lower their greenhouse gas pollution, are already flying biofuel-powered flights, and have won approval to fill their tanks with a fuel mix of 50 percent plant-derived biofuel. The military, wary of its dependence on billions of gallons of fossil fuels each year, has flown test flights in its MH-60S Seahawk helicopter and F/A-18 Super Hornet with more biofuel on order.

But seaweed is not quite ready for your gas tank. Cost and supply remain major barriers: the price of the military biofuel contracts ranged from $67 to $424 per gallon once R&D costs are included, and despite millions of dollars flowing into startups during the last decade, mass commercial production is still on the horizon. For kelp, new chemical enzymes and growing techniques will be needed before achieving necessary scale. One study estimated the cost of raw materials needed to drop 75% from today's levels before kelp would become commercially viable.

Still, pilot projects are advancing. Chile, Scandinavia, and Scotland have embarked on research and public-private partnerships to commercialize kelp for biofuel, while U.S. startups are busy hooking up tanks of the algae to the carbon dioxide-rich exhaust of power plants to grow biofuel. Since almost any plant material can be used as a feedstock to supply the multi-billion dollar biofuel industry, the best source will have to be scalable, affordable, and sustainable. The race is on, and kelp may quickly come from behind.

[Image: NOAA's Flickr stream]

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