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A demonstration project that harvests algae grown in waste water for biofuel production is underway in Spain.
Work started earlier this year on building the first culture ponds for the project called All-Gas in the town of Chiclana, near Cadiz in southern Spain. Waste water from a nearby water treatment plant will fill the ponds, with the algae using sunlight to grow on the nutrients in the water.
The €12million project is part funded by the EU. It is one of the first attempts to take the production of biofuels from algae out of the laboratory and into real world. “There has been a lot of hype about algae biofuels, but now the EU has thrown down the gauntlet,” said Professor Charles Banks, director of the environment group at the University of Southampton, who is involved in the project.
Usually the company treats the waste water to get rid of the nutrients, which can be costly. With the new technology it can be turned into a valuable resource.
Frank Rogalla, leader of the project at Aqualia, said: “We are turning an expensive environmental problem of cleaning polluted waste water into a sustainable bioenergy source.” The objective of the current project is to show that algae biofuels are feasible on a large scale, he adds.
The micro algae will be grown in raceways where the water is moved, aerated and injected with CO2. Later it will be harvested and processed to extract oil for biodeisel, and other chemical by-products. The remaining algal and waste water biomass will be converted into biomethane in a biogas plant.
The project will be scaled up over five years to cover a 10 hectare site by 2015. Assuming that the ponds reach a harvest of 3000kg of dry algae per day, with an oil content of 20%, the project will supply 200,000 barrels of oil and 600,000 m3 of methane per year.
The EU renewable energy directive calls for the use of transport biofuels to triple from current levels of 2.4%, to 10% by 2020.
Algae has advantages over other biofuel crops – it has higher yields and grows faster than oil palm, sugar cane and canola. Less land is needed to grow algae compared with conventional biofuel crops, so it does not compete with food production.
Banks added: “It will not be plain sailing, a lot of work is needed to develop these systems to become energy efficient.” But he is optimistic that algae biofuel systems can work in the less sunny climates, including the UK.