Researchers from the University of Sheffield in the UK have developed a new method, using microbubble technology, to double algae cultivation for biofuel.

The technology allows algae particles to float on the surface of the water, making it easier to harvest them and in the process also saving time and money. Microbubbles use 1,000 times less energy, compared to existing flotation systems. In addition, the cost of installing the microbubble system is also expected to be smaller than existing systems.

According to the researchers, it is difficult to cultivate algae for the purpose of producing biofuel because it is a time-consuming process. Furthermore, until now, there really was no cost-effective method of harvesting the algae and processing it effectively. This new development, however, could make such problems a thing of the past.

The scientists collaborated with the Tata Group in India and are next planning to develop a pilot plant to test the system at an industrial scale. In fact, work is already under way, at Tata Steel's Scunthorpe site, using CO2 from their flue-gas stacks.

Biofuel is produced from the oil that algae produce; it is, therefore, an environmentally friendly source of power, since it is made from plants, an important alternative to fossil fuels. Microbubbles, on the other hand, are bubbles smaller than one millimetre in diameter but larger than one micrometer. They have been previously used by water purification companies, who float impurities through them.

"We thought we had solved the major barrier to biofuel companies processing algae to use as fuel when we used microbubbles to grow the algae more densely," said Will Zimmerman, Professor at the University of Sheffield.

"It turned out, however, that algae biofuels still couldn´t be produced economically, because of the difficulty in harvesting and dewatering the algae. We had to develop a solution to this problem and once again, microbubbles provided a solution," he said.

"Professor Zimmerman´s microbubble-based technologies are exactly the kind of step-change innovations that we are seeking as a means to address our emissions in the longer term, and we are delighted to have the opportunity to extend our relationship with Will and his team in the next phase of this pioneering research," said Dr. Bruce Adderley, Manager Climate Change Breakthrough Technology.