LAWRENCE — Perhaps humanity’s greatest undertaking today is the creation of new, sustainable energy sources to replace fossil fuels. Promising, but challenging, energy solutions include biodiesel and other liquid transportation fuels that can be produced from the lipids contained in algae.
“The growth rate of algae is far greater than for domestic crops — these are little organisms that grow like crazy,” said Val Smith, professor of ecology and evolutionary biology at the University of Kansas. “Their growth rate is so much higher than food crops that the potential yield per acre of oil from algae is more than a hundred times greater than corn.”
Smith is involved in a major effort to develop algal biofuels that is under way at KU as part of its multidisciplinary Feedstock to Tailpipe Initiative, which is overseen and supported by KU’s Transportation Research Institute.
“We have an excellent group composed of ecologists, civil engineers, chemical and petroleum engineers, mechanical engineers and a geographer that really looks at the entire chain of biofuel production from cells to ecosystems,” he said. “That’s unique about what were doing here at KU — we’ve got people at the ground floor looking at physiology and cultivation of algae cells, and there are experts at every downstream linkage in the biofuel production process up to and including tailpipe pollution.”
Smith said that algae have many advantages as a biofuel source: They can be grown in closed “photobioreactors” or in shallow ponds on marginal lands that don’t compete with food crops or take up valuable farmland.
“Many of us believe that the promise of algal biofuels could potentially be helped along by using wastewater,” said Smith. “It provides a convenient source of water, and it also provides nutrients that otherwise would be released to receiving waters, like rivers, and lost to human use. It would be great to take the water that’s already being provided by a wastewater plant, plus nutrients that it contains, and then grow algae.” In fact, some of the KU research is being carried out in collaboration with the Lawrence, Kansas, domestic wastewater treatment plant.
Other research into algae cultivation is taking place at the field station that KU maintains north of Lawrence.
“We have dozens and dozens of ponds,” Smith said. “We use 10-cubic-meter fiberglass tanks that can be used as large outdoor test tubes and a series of one-tenth-of-an-acre ponds that are 9 feet deep. We have almost 80 of those ponds, and each actually is plumbed like a bathtub so we can fill them and empty them at will.”
Such is Smith’s expertise that he recently helped to produce a much-anticipated report on algae-derived biofuels for the U.S. National Academy of Sciences, which was released in October. The report characterized the future of large-scale production of algal biofuels as promising, but fraught with hurdles such as the high quantity of water needed, high requirements for the same plant nutrients that are used in commercial agriculture and the large energy inputs that will be needed to mass-produce algae-based fuels at billion-gallon-per-year levels.
Even with such challenges, Smith sees a bright future for algae as a feedstock for transportation fuels, once the right combination of factors can be identified and developed through careful research. He said KU is in the vanguard of those efforts.
“We’re trying to uncover the optimal growth conditions that maximize the yield of algae per acre per year,” said Smith. “There are so many ways to tweak this — we’re asking which combination is the best.”