If the urgency of identifying cleaner alternative fuels receded with gasoline prices two summers ago, it's back with a vengeance as Americans watch thousands of gallons of oil flowing daily from BP's deepwater rig in the Gulf of Mexico.
While next-generation cellulosic ethanol gets most of the headlines and government funding, backers of another potential fuel source — algae — are touting scientific gains that could provide even greater hope for weaning the nation off oil and reducing carbon dioxide emissions.
The Donald Danforth Plant Science Center in Creve Coeur has emerged as a hub for algae-to-biofuel research thanks to millions of dollars in donations and grants, including a $25 million gift from local billionaire Jack Taylor that established the Enterprise Rent-A-Car Institute for Renewable Fuels.
Former Ohio State professor Richard Sayre was hired two years ago to lead the institute.
Within the past couple of years, algae technology has drawn the interest of major oil companies such as Exxon Mobil Corp. The companies are investing millions and forming partnerships to explore algae's potential as a fuel source.
How soon will it be before I can go to the corner gas station and fill up with an algae-based biofuel?
I think optimistically it's going to be nine years before we see full-scale production facilities that are going to make major contributions to our energy supply, and you'd have to add on 10 years before you can really potentially replace petroleum.
What are the benefits of algae versus other biomass feedstocks?
Algae are at least twofold more productive in generating total biomass than any terrestrial system. If you're looking particularly at fuels, they're 10-fold more productive than current biofuel systems.
A very important aspect is that they produce oils rather than sugars, which are fermented to make alcohol. That has a couple of advantages. When you ferment sugars to make alcohol, you lose a lot of the carbon to make those sugars, and that is emitted into the atmosphere. With oil we don't lose any of that carbon.
The other point is carbon dioxide. This is a clear case where algae outperform any terrestrial-based system. We can actually use CO2 from point sources such as power plants ... or even ethanol refineries as a fertilizer to enhance the growth of the algae.
Another important aspect of the sustainability is we can use municipal sewage wastewater as a source of both water and nutrients, so we can clean up the wastewater, remove nutrients from it to grow the algae and discharge much cleaner water. And you can grow them on non-arable land, marginal land, so it doesn't need to compete directly with food production.
It's technically feasible to produce fuel from algae right now, so isn't cost is the big barrier?
The major issue is economics. Can we get it down to be competitive? Two or three years ago we were talking about $100 to $1,000 a gallon. Now pilot plants are claiming they can get to $2 a gallon. That's a huge leap, it's taking into account a lot of technical innovation both on the production side and on the harvesting side.
What role does genetic engineering play in making this cost feasible?
To date, none. In the future, a lot. We estimate we can see two to three-fold increases in productivity with (genetically modified organism) technology.
There are other issues that will be addressed with GMO technology. For example, contamination issues — weedy algae growing in the pond that don't produce very much oil. Bacteria or fungi or viruses that are going to cause pathologies in the pond. Improved nutrient utilization efficiencies. Fertilizers are a big cost issue in growing algae. If we can improve the efficiency of nutrient utilization and capture, that's going to be a big issue. Heat stress. If you're going to grow algae in the desert you've got to address issues of heat stress.
On the harvesting side, harvesting algae is one of the costly components of producing fuel. It can be up to 40 percent or 50 percent of the cost. We anticipate their may be some way of either secreting out oil directly into the pond from the algae and then recovering it or engineering the algae to facilitate their harvesting.
Geographically, what are the most likely sites for algae to be grown in the United States?
I'm associated with a group that wants to make the case that the Southwest is the best place to grow algae. I'm not convinced that (region) is maybe the best place.
The advantages that the Southwest has is a lot of sun of course, and they also have a lot of non-arable land — desert — available. The major constraint is they have too much sun, too high of temperatures and too little water. So those are the major constraints for the Southwest.
The Southeast, on the other hand, has lots of water, comparable temperatures and similar light intensities over the course of the year, so we like the Southeast, and we can throw Missouri into that.
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