Biofuel in the picture: Algae

Due to high oil prices and the competing demands between foods and other biofuel sources, such as palm and soybeans, due to the world’s food crisis, interest in biofuel from Algae is higher than ever before. Algae are one of the fastest growing plant species in the world. Some strains of algae can even grow so rapidly that they double in size every day, producing large amounts of lipids (oils). The compositions of these lipids are somewhat similar to petroleum molecules and scientists have figured out how to transform these lipids into biofuels.

It is said that, due the prolific ability of algae, algae can produce over 7,500 gallons of fuel per acre in a single year. Compared to soybeans, which is the main source of biodiesel in the United States, algae produces 150 times more biofuel per acre per year. If we would displace all of the petroleum that the United States uses for transportation in a single year and use biofuel from algae instead, we only need a little more than 1% of the total landmass in the United States to produce all the algae we need.

Furthermore, algae are not only quick growers, they also use carbon dioxide as a nutrient source. Another attractive characteristic of algae is that they do not affect fresh water resources, they can be produced using contaminated or ocean water and are biodegradable, which means that they are relatively harmless to the environment if something bad would happen. The ability of algae to grow almost everywhere gives producers the opportunity to grow them on marginal or desert land. This means that algae will not compete with crops for fertile soil.

Growing Algae

There are several ways to grow algae, some companies are growing algae in big open ponds others use photo-bioreactors to grow the algae under perfect conditions. The big open ponds may represent the most closely thing to nature, they are not as efficient at controlling the amount of light and nutrients that the algae must receive for optimal growth. Photobioreactors (PBR) on the other hand, are enclosed vessels that manipulate algae’s environment for maximum lipid growth. PBR’s are tubes pumped with nutrient-laden water which are exposed to sunlight. Where photo-bioreactors may have much higher yields compared to open ponds, PBR’s are a lot more expensive due to the build of acres of plastic tubes.

Another method to grow algae is fermentation. With fermentation algae are grown in dark steel drums with no access to light. All the algae get is a consistent supply of sugar. The costs of these technologies (open pond, PBR, fermentation) still need to be refined in order to become cost effective. Because the technology of extracting biofuel from algae is still in its infancy costs are expected to go down in the next coming years. As of 2008, biofuel from algae remains too expensive to replace other commercially available fuels where costs of various algae typically generate around 5 to 10 dollars per kilogram.

Future: Algae farms next to power plants

An expert team of the University of Virginia hypothesizes that when you feed algae more carbon dioxide and organic material, it could boost the lipids (oil) yield by as much as 40%. This would not suggest that biofuel from algae is carbon neutral, but it does give us the potential to cut current emission by for example placing algae farms near power plants. These power plants, such as coal power plants, produce gas which contain about 10 to 30 times as much carbon dioxide as normal air. Connecting these two together would reduce total emissions by a significant factor, eliminating the introduction of new carbon dioxide into the air.

Source : http://www.tomorrowisgreener.com/biofuel-in-the-picture-algae/