In the discussion of alternative energy and fuels, algae have been bubbling to the top of the proverbial feedstock pool. Algae, the little green guys responsible for everything from making your Dairy Queen Blizzard solid to forming the basis of our current fossil fuels, are being looked at long and hard by some of the nation's top researchers and decision-makers as a source for next-generation biofuels.
Biofuels are already produced in large quantities. In the United States, corn is used to produce tens of millions of gallons of the ethanol each year. Biodiesel, produced in smaller volumes, can be produced from everything from waste cooking oil to soybeans and tropical plants.
Unfortunately, corn ethanol and terrestrial plant-based biodiesel face significant environmental and social dilemmas. Reliance on food crops for fuel poses problems for populations around the world that rely on basic staple foods such as corn. Deforestation is rampant in tropical climates as forests are cut down to accommodate oil crop production. And all of these crops require vast amounts of land and water.
The idea is that algae can avoid some of the problems facing our current sources of biofuels. As evidenced by algae growing in backyard pools around the nation, algae aren't the pickiest organisms; algae primarily require sunlight, carbon dioxide and water to grow. Carbon dioxide can come from power plants and industrial emitters, which not only results in faster growth, but also would let carbon dioxide from fossil fuels be recycled before being emitted to the atmosphere. Unlike terrestrial crops (like corn), algae can utilize wastewater for growth, reducing demand on scarce water resources.
And most important, algae produce useful compounds that can be formed into fuels and chemicals desperately needed by our society. Synthetic gasoline and diesel, jet fuel, ethanol and biodiesel can all be produced from different parts of the algal biomass and lipids, while some algae strains have been shown to produce hydrogen.
Although algae are appealing, it will be awhile before we'll be filling up our tanks with algae-based fuel: A recent article published in Science details the research needed to advance algal biofuel production. In short, researchers and engineers need to know more about every stage of the process, from what alga species to grow to the exact growth conditions and production processes.
The state of algal biofuel science is maturing quickly but is still very much in the early stages. Algal biofuel production is very similar to the beginnings of modern agriculture years ago. If you asked a farmer today to plant a crop, he would know exactly what seeds to sow, crop rotations and nutrient requirements. Ask someone to grow algae for biofuels today, and you'll get as many answers as there are alga species.
The future is bright, though. With advances in research, our energy future might be bright green.
Pienkos, P. (2009). The Promise and Challenges of Microalgal-Derived Biofuels. Biofuels and Bioproducts 3 (4). doi: 10.1002/bbb.159
Schenk, P. (2008). Second Generation Biofuels: High-Efficiency Microalgae for Biodiesel Production. Bioenergy Research 1:20-43. doi: 10.1007/s12155-008-9008-8
About The Author: David Wogan is a dual-degree graduate student at The University of Texas at Austin in Mechanical Engineering and Public Affairs. David's work includes the integration of engineering, biological, and policy disciplines to assess advanced biofuel production in Texas. David received his B.S. in Mechanical Engineering from UT Austin in December 2006. David has worked at National Instruments and at the White House Council on Environmental Quality on the Energy & Climate Change Team. David is a currently a graduate researcher with the Webber Energy Group and writes at The Daily Wogan, his energy and sustainability blog.
The views expressed are those of the author and are not necessarily those of Scientific American.