Algae not that green after all?

Bio fuel from algae is currently being considered as the next big thing. Research had already began at the time of the oil crisis, but ceased when oil prices appeared to drop. Now, as we are all in search of alternatives to fossil fuels, algae is once again high on the agenda. Algae seems to have lots of advantages over brother and sister bio fuel sources, but new research suggests that while algae might produce good fuel, the environmental costs involved in the production would be heavy.

Micro algae are single-celled photosynthesizes. They are extremely efficient at converting carbon dioxide into biomass. The fats they contain can be converted into bio diesel or jet fuel in relatively few steps. Agriculturally it’s very easy to grow, algae doesn’t require a lot of land like other crops. In the US you will find algae farms primarily in desert areas, where no vegetation is found. So another plus is that they don’t use up valuable farm land.

A life-cycle assessment published in the journal Environmental Science and Technology argues that algae production consumes more water and energy than other bio fuel sources like corn, canola, and switch grass, and also has higher greenhouse gas emissions. The algal life-cycle analysis, which used numbers from an online database and published research, finds that algae farms need to minimize use of fertilizer and freshwater to compete with the other bio fuel plants. So it’s not so much the algae themselves, more the condition they are grown in that seems to be the problem.

Algae farms should cut down on using chemical fertilizer, according to the researchers.. Growing algae for bio fuel requires large amounts of fertilizer, this undermines the carbon dioxide saving effect that the algae possesses. Corn and switch grass are capable of retrieving nitrogen from the soil, so they don’t need lots of extra fertilizer. The only arena where algae came off better than corn, switch grass and canola, were land use and nutrient runoff. The scientists believe that a way for the algae to get out of the red would be to put algae operations next to waste water treatment plants or facilities that emit carbon dioxide. From waste water they can capture phosphorous and nitrogen — essential nutrients for growing algae that would otherwise need to be produced from petroleum.

Scientist theorize that algae can produce 30 times more energy per acre than any other bio fuel option. The US department of Energy have estimated that if algae bio fuel replaces all conventional fuel in the country it would require 15.000 square miles of land to harvest the algae which is roughly one seventh of the area that is used to harvest corn in the US every year. Despite some hurdles to conquer, it seems the “green gold” remains to be one of the most promising bio fuel sources around and we’re not ready to give up on it yet.

http://www.sciencenews.org/view/generic/id/55665/title/Algae_as_biofuel_still_rough_around_the_edges

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