Last semester I worked on a feasibility study for a company started by a UT professor which is looking to commercialize algal farming for use as a feedstock in biofuels. Algal biofuel is not a new concept and in fact there has already been a significant amount of investment in this area of energy research by both the public and private sectors. Since I am a business student my work on the feasibility project focused on the business case and cost perspectives rather than the engineering and biology involved. Though I am not an engineer and do not have a thorough understanding of all the biological and engineering processes going on, I did developed a reasonably good understanding of how we can utilize algae and the potential benefits from this form of energy.
So, the question is what exactly am I writing about? I was sent an article by a former team member about a paper, recently published (1/19/10) in the journal Environmental Science & Technology, in which researchers from the University of Virginia’s Department of Civil and Environmental Engineering claim that algae used for energy has a higher environmental footprint than other recent (conventional) biofuel production methods such as switchgrass, canola, and corn farming. Their claim is that “these conventional crops have lower environmental impacts than algae in energy use, greenhouse gas emissions, and water regardless of cultivation location.” The report suggests that “The large environmental footprint of algae cultivation is driven predominantly by upstream impacts, such as the demand for CO2 and fertilizer.” Additionally the report mentions that “To reduce these impacts, flue gas and, to a greater extent, wastewater could be used to offset most of the environmental burdens associated with algae.”
The two key arguments available in the abstract of the research paper regarding water and CO2 emissions were negated by the researchers when it was suggested that waste water and flue gas be incorporated into the process. This is the same assumption industry has been working with for sometime in the effort to commercialize this technology. Again, I must mention that I am not an engineer and the UVa researchers have more knowledge on this topic than I do. That said, I still question how accurate the conclusion is that algae based fuel are not as environmentally friendly as traditional bio fuels based on what I learned from working on a algae biofuels project.
The project I worked on last semester assumed water used for the algal ponds was either treated municipal waste water or water from nearby streams or lakes. Both of these types of water would provide nutrients for the algae to grow. Lake or river water would be cycled through the ponds as necessary and released back just as clean as or cleaner than when it was used in the ponds. This is a key assumption in the algae as a fuel source argument because it shows that no fresh water is soiled in the algal growth process. So while algal ponds do require an enormous amount of water, they do not diminish available water for our consumption.
Another key assumption we made was that the algal farms would be placed near a coal burning power plant were we could utilize the post scrubber emissions to feed CO2 to our algae. This not only provided food and temperature regulation for the algae, but also is a form of temporary carbon sequestration. The benefit here is that the carbon released from the power plant does not just go into the air, but is transferred to the algae which use it to grow. Though the CO2 will eventually be released when the algal oil is burned, the net effect is less than the amount released if the coal plant emitted CO2 directly into the atmosphere and crude oil was used as a transportation fuel rather than the algal oil.
Algae, because it can be grown in ponds does not need fertile soil like traditional crops so it does not compete with food crop for land. This is a major advantage over ethanol. More specifically algae can be grown on undesirable land around a power plant which is generally bare and undeveloped.
Ethanol also has logistical problems associated with its transportation. Ethanol is hygroscopic and cannot be transported through our existing pipeline infrastructure the same was gasoline and oil are; algal based biofuels do not have this restriction. Furthermore, the process we were working with assumed that the type of algal oil our process yielded could be directly mixed and refined with traditional crude oil allowing it to utilize a transportation and refining infrastructure already in place.
Algal oil is not an easy solution to our energy addiction, and it will likely never fully replace traditional crude oil. Algal oil is however a game changer and can help diversify of our energy portfolio. Algae based bio fuels have the potential to help reduce our dependence on oil as the primary transportation fuel, while also reducing the environmental strain caused by our current energy use.