As the world mulls the question of how to satisfy a seemingly endless appetite for energy and still slash greenhouse gas emissions, researchers have stumbled upon an unexpected hero in algae. So-called microalgae hold enormous potential when it comes to reining in both climate change - since they naturally absorb large amounts of carbon dioxide - as well as energy production, since they can easily be converted to a range of different fuel types. "This is certainly one of the most promising and revolutionary leads in the fight against climate change and the quest to satisfy energy needs," said Frederic Hauge, who heads up the Norwegian environmental group Bellona. The idea is to divert exhaust spewed from carbon burning plants and other factories into so-called "photobioreactors," or large transparent tubes filled with algae. When the gas is mixed with water and injected into the tubes, the algae soak up much of the carbon dioxide, in accordance with the principle of photosynthesis. The pioneering technique, called solar biofuels, is one of several novel methods aiming to crack the problem of providing energy but without the carbon pollution of costly fossil fuels or the waste and danger of nuclear power. Studies are underway worldwide, from academia in Australia, Germany and the US, to the US Department of Energy, oil giant Royal Dutch Shell and US aircraft maker Boeing. Once the microalgae are removed from the tubes they can easily be buried or injected into the seabed, and thus hold captive the climate changing gases they ingest indefinitely. And when algae grown out in the open are used in biomass plants, the method can actually produce "carbon negative" energy, meaning the energy production actually drains CO2 from the atmosphere. "Whether you are watching TV, vacuuming the house, or driving your electric car to visit friends and family, you would be removing CO2 from the atmosphere," Mr Hauge said. Instead of being stored away, the algae can also be crushed and used as feedstock for biodiesel fuel, and any residues from this could be used as fertiliser. "You kill three birds with one stone. The algae serves at once to filter out CO2 at industrial sites, to produce energy and for agriculture," he said. Microalgae have other advantages including its ability to grow in a wide range of conditions and their high oil yield. As attractive as it may seem however, the algae solution remains in the conception phase, with researchers scrambling to figure out how to scale up the system to an industrial level. Shell, for one, acknowledged on its website some "significant hurdles must be overcome before algae-based biofuel can be produced cost-effectively," especially the large amounts of water needed for the process. In addition, further work is needed to identify which species of algae is the most effective. Source: AFP/ABC
