I chose to research algae based biodiesel, and run a life cycle analysis for the requirements to replace 500 million gallons of diesel, about the amount used by a city the size of Austin anually, within the giuidelines given by the Energy Independence and Security Act of 2007. It was interesting for me as an engineering major to read policy, something I had not ever done before this project. Algae oil is still very expensive, one of its main detractions, and there are problems upscaling the technology for large scale use. One of the problems with large scale production of algae biodiesel is the land required for algae growth. Even using photobioreactors, rather than ponds, the land required for replacement of 500 million gallons was near 9 square miles.
I made several assumptions. Algae can be grown using CO2 from flue streams, which makes it more environmentally sound, and the nitrogen and phosphorous needed for nutrients can be aquired by pairing it with streams from waste water treatment facilities. This actually helped the case for land requirements, because multiple algae systems could be set up around several different waste water facilities. Overall, even including transportation from production sites to the pump, the life cycle analysis was extremely favorable energetically. Definitely something that should be looked into as a system of fossil fuel replacement.