Can algae be the next biofuel?
The lure of the oceans has always had a special appeal for advocates of biofuel. The vast reaches of the deep speak of a promise that unlimited amounts of space will be able to bring forth completely sustainable forms of energy.
“Two-thirds of the globe is covered with water,” says Khanh-Quang Tran, a Norwegian researcher who has published papers on the possibility of growing algae as a biofuel on an industrial basis. “If we used only a tiny portion of that space, we’d have enough to supply ourselves with all the fuel we needed.”
Of particular interest to researchers is one species, laminaria sacceyarina (“sugar kelp”), which grows along the coast of many countries, including Scandinavia. It is the “seaweed” that seems to be a flower but is actually all one undifferentiated cellular structure that takes on various forms in competing for sunlight. As the name implies, it contains lots of sugar – three times as much as the sugar beet. Scandinavian scientists have been especially intent on harvesting this plant for food and fuel use.
“It’s actually regarded as a nuisance, since it grows everywhere and clogs the beaches,” says Fredrik Grondahl, a researcher at the KTH Royal Institute of Technology in Sweden who heads the Seafarm project. “But it absorbs nitrogen out of the water, effectively as a wastewater treatment plant. It’s regarded as an environmental problem, but it’s actually a valuable resource.”
The big question will be this: Can a weed that grows so prolifically in the sea be domesticated so that it can grow in large quantities under controlled conditions?
Sweden and Norway seem to have taken the lead on this project, mainly because of their long coastlines, where the algae grows intensely in a cold climate. The Seafarm project involves growing underwater algae farms on ropes. The team collects excess algae from the Baltic Sea and cultivates it as food and fuel. One technique is called the “sporophyte factory farm.” The algae spores are sown onto ropes. They sink and grow in the sea. In about six months, they have grown onto the ropes and are harvested and processed on land covering two hectares. From there it can be converted to eco-friendly food, medicine, plastics and energy fuels such as methanol. The city of Trelleborg, where the farm is located, estimates that 2.8 million liters of fuel can be extracted from its algae resources.
Kahnh-Quang Tran of Norway has been following another line of research. He mixes a slurry of kelp biomass and water and heats it rapidly to 350 degrees Centigrade. Tran says the fast hydrothermal liquefaction gives him a product that is 79 percent bio-oil. A similar experiment on the U.K. was only able to produce 19 percent oil, but Tran claims that the rapid heating improves the process tremendously. “What we are trying to do it mimic the natural process that produces oil,” he said. “Whereas it takes geological time in nature to produce oil, we can do it in a matter of minutes.”
Tran is now looking for partners who can help him move up to an industrial scale.
Another plan developed in France and the Netherlands is to line highways with algae pools in the hope that they will immediately absorb the carbon exhaust that comes from automobiles. This will remove CO2 from the atmosphere and recycle the fuel as well. An experimental installation was demonstrated at the summer garden festival at Genève Villes et Champs this year.
Another country that is experimenting with algae is Australia. This October, the Muradel Corporation opened a $101. 7 million demonstration plant in Whyalla designed to produce 30,000 liters of green crude every year. The company is employing its Greeen2Black technology, designed to produce a continuous stream of environmentally sustainable crude equivalent.
Muradel CEO and University of Adelaide Associate Professor David Lewis said if the demonstration plant were successfully scaled to a commercial plant, it would produce 500,000 barrels of refinable green crude a year by 2019 – enough petrol and diesel to fuel 30,000 vehicles for a year. The planned 1,000-hectare commercial plant would create at least 100 new skilled jobs in the Whyalla region.
“This is world-leading technology which can be scaled up exponentially to help steer our fossil fuel-dependent economy toward a more sustainable future,” Lewis said.
Not everyone is enthusiastic about algae. “It will take anywhere from 5 to 15 years to produce on a scale that would be meaningful to the nation’s every needs,” says Jim Rekoske, general manager of Honeywell’s UOP division. He likened it to trying to maintain the water balance in a fish tank.
“You have to have just the right temperature and the right amount of carbon dioxide to get these growth spurts,” he said. Algae farms are also very susceptible to invasive species and have to be monitored constantly. Still, an acre of algae can ideally produce 15,000 gallons of biofuel per year, as opposed to only 420 gallons per acre from corn ethanol. “We could replace all the diesel we consume now on half of 1 percent of our current farmland,” says Douglas Henston, CEO of Solix Biosystems of Fort Collins, Colo. Solix is supplying the military with biofuels at a whopping $33 per gallon.
So, will algae make the same progress in the United State that it seems to be making in Sweden and Norway? American researchers may take up the challenge as well. The long coastal lines are not there to tempt us, but research breakthroughs may finally make algae biofuels more practical and economically viable everywhere.
