Science - August 12, 2010

Biodiesel from algae farms within 10 years

In 10 to 15 years' time, sustainable and viable biofuels could be produced from cultivated algae. This picture is given by Rene Wijffels, professor of Bioprocess Technology, and Maria Barbosa, researcher at Food & Biobased Research, in an article published in the latest issue of Science magazine.

The authors wrote the article, 'An outlook on microalgal biofuels', at the invitation of the magazine for a special about sustainable energy. 'The chance that large scale algae production could be employed in the production of biodiesel is big', Wijffels contends. 'Algae cultivation is currently still a small-scale business, but we have all the ingredients to produce sustainable and viable biodiesel from algae on a large scale.' Wijffels and Barbosa calculated that 0.4 billion cubic metres of diesel oil are needed to provide transport fuel for the entire European market. To do this, a land area as big as Portugal is required. However, to make algae cultivation viable, other valuable substances of these microscopic plants, besides their oil, have to be used as well. In addition, the cost price of algae cultivation needs to go down by a factor of 10, while productivity has to triple. 'It is certainly possible to produce cheaper algae oil in the future', says Barbosa confidently. 'We need to build better cultivation systems and make more efficient use of nutrients, for example, by recycling cultivation liquids.' The algae themselves can be improved in one way or another. They would have to produce a lot of fats, to tolerate high light intensity, and be resistant against infections.
Rain forest
Algae are by far the ideal candidates for supplying sustainable energy. They can be cultivated in closed systems unsuitable for agriculture and which have very little biodiversity, such as desserts. As such, algae cultivation, unlike the cultivation of oil palms, does not require areas of rain forest to be cleared. Furthermore, algae require very little sweet water. To produce a litre of biodiesel from algae, only 1.5 litres of water are needed, while agriculture crops need 10,000 litres of water for every litre of biodiesel produced. Moreover, algae produce much more oil compared to traditional fatty agriculture crops. 'Algae is sometimes half oil in its composition', says Wijffels. 'As a result, you can harvest about six times as much oil from them as from oil palms.' Besides a big oil supply, algae also provide valuable by-products such as high quality proteins, vitamins and minerals. 'If algae are actually used to produce the needed 0.4 billion cubic metres of diesel, we would get much more proteins as a by-product than we can ever consume: forty times more than the amount of soya protein which we currently import into the EU', says Wijffels. 'As a result, the entire 'food for fuel' debate could take on another perspective.'

Test facilities
AlgaePARC, the Wageningen test facility for algae cultivation, will, from next year onwards, concentrate on how to improve cultivation technologies. After the pilot phase, which will last about five years, the research team,  led by Barbosa, will implement the best technology on a large scale. 'We will keep a close watch throughout the development phase and continually monitor the ecological impact of the cultivation, concludes Wijffels.