Algae could make biofuel cheaper than oil

3rd April, 2011

Algae that thrive in sun-drenched wildernesses are an important source of natural nutrition and biofuel. But while most projects have grown algae in closed conditions, there is hope that the open environment of the UAE desert might also be suitable. Megan Detrie reports

The desert might not seem an ideal setting for algae to thrive. But biologists believe its abundant sunlight and unused land could make it the perfect place for the tiny plants that can be used to make a versatile oil for food and fuel alike.

Microalgae - single-celled microscopic relatives of seaweeds - have attracted global attention in recent years as a source of natural food supplements for humans and animals, and possibly as a biofuel.

The algae are an important source of omega-3 oils, rich in essential fatty acids as well as antioxidants which work against the ageing process, and carotenoid, a natural food pigment and source of vitamin A. Oils that build up in the cells of the algae when they are starved of nutrients can also be extracted for use as feed in fish farms or for chicken.

A handful of start-ups in the US and Europe have worked on ways of converting waste carbon dioxide into fuel-producing algae, but until now the cost has been too high to make it commercially viable.

But one biologist now plans to make the UAE a centre of microalgal business in the Middle East.

David Francis, a biologist who now works as a management consultant, hopes to create partnerships with research universities in the UAE, as well as working with farmers and businesses to develop particular strands of the pond scum.

"Before we can begin growing commercially, we need to know what products investors need here," he said.

He is looking for funding for a pilot study, and believes the UAE's sun-drenched empty spaces could be just the ticket for the algae, which grow with few nutrients in brackish or waste water, and on land unsuitable for crops.

"The research must be locally based, so that the results can be recreated," he said.

Mr Francis plans to try several approaches to mass-producing the slime. It can be farmed in ponds or in photobioreacters, closed translucent reactors that act as a vessel for growth and incorporate some kind of light source.

Closed systems have many advantages, allowing a single strain of algae to be grown in sterile conditions at higher densities, and with less risk of contamination.

They also give better control over growing conditions, such as acidity, light, carbon dioxide levels and temperature.

But they cost far more. That, according to Robin Shields, the director of the Centre for Sustainable Aquaculture Research in Wales, makes open ponds - often little more than shallow channels, open to the sun and with an external source of nutrients - far more popular.

Whichever system is used, the result is algae that can be collected either by skimming or filtration. If the algae are skimmed off the top of the water, they can then be mixed with a solvent to separate the fats from sugars, or spun in a centrifuge that pushes the heaviest materials to the bottom.

Alternatively they can be filtered, to aggregate the cells. The water is then removed, leaving flakes of oil-containing algae that can be processed further.

"It is the simplest technology on the face of it, but there is a lot of capital investment," Dr Shields said.

The potential benefits go far beyond food supplements. Algae could produce biofuel using far less water than the grain crops currently in widespread use.

A new technique being developed by VG Energy, a US alternative energy and biotechnology company, uses a process originally designed as a cancer treatment to dramatically boost algae's biofuel yield.

The process, called metabolic disruption technology, was devised to disrupt cancer cells' ability to burn fat reserves, making them more susceptible to chemotherapy.

But the same technique also produces algae cells that can store up to four times the normal amount of oil. Not only that, the process also enables the cells to release fat outside the cell wall - so the algae survive the harvesting process. Currently, the algae is killed during the process of removing the oil

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