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From Cheese Car to Green Car

31 January 2013
Published in Energy
Written by  Christian Probasco
From Cheese Car to Green Car Courtesy of Michael Morgan

A cheese-powered race car made headlines across the nation when it set the land speed record for the small diesel engine category last September at the Bonneville Salt Flats. While the record of 64.396 miles per hour was later beaten, this was the first time a demonstration project was fueled by biodiesel made from the byproducts of cheese.

The race car project is a collaborative effort led by Utah State University researchers Byard Wood, Lance Seefeldt, and Bruce Bugbee whose expertise cover the gamut of engineering, biochemistry, and plant biology.

To make the cheesy fuel, the researchers first grew yeast in a stew of cheese byproducts, water and whey protein. Then they extracted energy-rich lipids, fats and sterols similar to cholesterol out of the yeast, and converted it into the fuel that powered the Aggie A-Salt Streamliner's 836cc engine. This demonstration project is now being adapted to synthesize biofuels from algae or other microbes that can be cost-competitive with petroleum fuels.

Algae as Fuel

Algae can have high lipid content and can yield far more biofuel by weight than other sources such as palm or soybeans. As an added bonus, they wouldn't compete for many of the high quality land resources that are used to grow food crops.

But there are challenges to creating fuel from algae including choosing or developing a strain of algae that will always thrive and deliver high yields of lipids for conversion to fuel, says Bugbee. "This is agriculture. We're at the same point [with biofuels] that mainstream agriculture was at 100 years ago."

His group is responsible for helping to develop algae strains that will be useful for creating biofuel, " [We] winnowed down the number of algae strains...from 3,000 to six," says Bugbee. He adds that even with the right candidates, actually getting the organisms to reliably produce fuel involves a lot of calculated trial and error. "We have to stress the algae to create lipids," he says. "We have to harvest them at just the right time. And we have to do it consistently."

Bugbee says currently about one in four batches is lost before it yields high lipids. But on the positive side, each batch only takes seven days to mature.

Will Algae Fuel Ever Be Cost Effective?

Skeptics doubt whether production-costs for algae-derived fuel can ever be brought low enough to compete on the market with conventional fossil fuels. So far, nobody has perfected a reliable, economical model for growing and harvesting algae and converting it to biofuel on a commercial scale. A recent report from The National Academy of Science Research Council says challenges with energy, water, and nutrient resources will make it difficult for algae biofuels to become a sustainable energy source.

Aware of these limitations, the USU team will initially be aiming for a smaller market: biodiesel additives.

Today, nearly 5 percent of the diesel most U.S. drivers put in their tanks, about 50-million barrels, is actually biodiesel additives. Though smaller, this market is more lucrative than fuel. "Flying J [travel center] is paying $5 a gallon for biodiesel from soybeans," says cheese car racer and research assistant Michael R. Morgan.

The niche market didn't exist until 2006, when the Environmental Protection Agency mandated that the U.S. reduce sulfur content in diesel fuel. Though sulfur increases emissions, it is beneficial to engines because it increases lubricity. Without another element to compensate, diesel engines running 'Ultra-low sulfur diesel' ULSD would grind their metal parts. Biodiesel from crops like soybeans has the lubricant qualities modern diesel engines need without the sulfur.

To be competitive, the USU's algal-biofuel must be no more costly than soybean biodiesel. Seefeldt says the USU team has made big strides bringing down the costs of algae-biodiesel. "We are developing several approaches that simplify the extraction process from algae," he explains. "Most significant is a procedure that extracts all of the lipids without having to remove any water from the algae."

The USU group has a lot of competition with companies and Universities across the globe investing in research into algae. Now the race is really on.

The group published their results of the engine performance and emissions characteristics of each of their microbial fuels in Energy and Fuels on November 12, 2012. Here.

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