A Biofuel Process to Replace All Fossil Fuels

A startup unveils a high-yield process for making fuel from carbon dioxide and sunlight.

By Kevin Bullis

Solar farming: A photobioreactor houses photosynthetic microorganisms that use the energy in sunlight to make fuel and other chemicals from carbon dioxide and water. 

Joule Biotechnologies

A startup based in Cambridge, MA--Joule Biotechnologies--today revealed details of a process that it says can make 20,000 gallons of biofuel per acre per year. If this yield proves realistic, it could make it practical to replace all fossil fuels used for transportation with biofuels. The company also claims that the fuel can be sold for prices competitive with fossil fuels.

Joule Biotechnologies grows genetically engineered microorganisms in specially designed photobioreactors. The microorganisms use energy from the sun to convert carbon dioxide and water into ethanol or hydrocarbon fuels (such as diesel or components of gasoline). The organisms excrete the fuel, which can then be collected using conventional chemical-separation technologies.

If the new process, which has been demonstrated in the laboratory, works as well on a large scale as Joule Biotechnologies expects, it would be a marked change for the biofuel industry. Conventional, corn-grain-based biofuels can supply only a small fraction of the United States' fuel because of the amount of land, water, and energy needed to grow the grain. But the new process, because of its high yields, could supply all of the country's transportation fuel from an area the size of the Texas panhandle. "We think this is the first company that's had a real solution to the concept of energy independence," says Bill Sims, CEO and president of Joule Biotechnologies. "And it's ready comparatively soon."

The company plans to build a pilot-scale plant in the southwestern U.S. early next year, and it expects to produce ethanol on a commercial scale by the end of 2010. Large-scale demonstration of hydrocarbon-fuels production would follow in 2011.

So far, the company has raised "substantially less than $50 million," Sims says, from Flagship Ventures and other investors, including company employees. The firm is about to start a new round of financing to scale up the technology.

The new approach would also be a big improvement over cellulose-based biofuels. Cellulosic materials, such as grass and wood chips, could yield far more fuel per acre than corn, and recent studies suggest these fuel sources could replace about one-third of the fossil fuels currently used for transportation in the United States. But replacing all fossil fuels with cellulose-based biofuels could be a stretch, requiring improved growing practices and a vast improvement in fuel economy.

Algae-based biofuels come closest to Joule's technology, with potential yields of 2,000 to 6,000 gallons per acre; yet even so, the new process would represent an order of magnitude improvement. What's more, for the best current algae fuels technologies to be competitive with fossil fuels, crude oil would have to cost over $800 a barrel says Philip Pienkos, a researcher at the National Renewable Energy Laboratory in Golden, CO. Joule claims that its process will be competitive with crude oil at $50 a barrel. In recent weeks, oil has sold for $60 to $70 a barrel.

Joule's process seems very similar to approaches that make biofuels using algae, although the company says it is not using algae. The company's microorganisms can be grown inside transparent reactors, where they're circulated to ensure that they all get exposed to sunlight, and they are fed concentrated carbon dioxide--which can come from a power plant, for example--and other nutrients. (The company's bioreactor is a flat panel with an area about the size of a sheet of plywood.) While algae typically produce oils that have to be refined into fuels, Joule's microorganisms produce fuel directly--either ethanol or hydrocarbons. And while oil is harvested from algae by collecting and processing the organisms, Joule's organisms excrete the fuel continuously, which could make harvesting the fuel cheaper.

David Berry, one of the company's founders and a board member, says the organism they use was selected and modified to work well in a bioreactor, and the bioreactor was designed with the specific organism in mind. He adds that the company carefully considered issues such as the organism's response to heat, and the reactor was built to keep the heat within bearable limits. Overheating has been a problem with bioreactors in the past.

The company will likely face many challenges as it attempts to scale up its process. Other companies, such as Green Fuels, have failed to produce biofuels economically in bioreactors because of the high cost of the reactors compared to the amount of fuel produced. Another challenge is keeping the microorganisms producing fuel at a steady rate. Algae populations can bloom and grow so quickly that they outrun the supply of nutrients or sunlight, leading to a collapse of the population, says Jim Barber of Barber Associates, who was formerly CEO of Metabolix, which produces chemicals from renewable resources. "You get a burst and then they all die off," he says.

Joule Biotechnologies will also face stiff competition. It is not the only company developing photosynthetic organisms that excrete fuel. Synthetic Genomics, which recently announced a research partnership with ExxonMobil, has developed organisms that excrete fuel, as has Algenol, which recently announced a partnership with Dow.

Source: Technologyreview 1 and Technologyreview 2