How Tiny Algae Could Be the Big Future of Carbon-Free Fuel

A government-funded consortium hopes to overcome obstacles to powering cars and jets—with pond scum.

Chemist in front of algae fuel processing tubes (Photo: Steve McAlister/Getty Images)

Jun 18, 2014· 1 MIN READ
Katharine Gammon has written for Nature, Wired, Discover, and Popular Science. A new mom, she lives in Santa Monica.

Despite the hundreds of millions of dollars invested in companies aiming to power the world with pond scum, algae seems to perpetually be the fuel of the future. Now a government-funded consortium hopes to jump-start commercialization of the low-carbon fuel by developing new strains of algae that grow faster as well as creating better technology to process algae into fuel.

The United States Department of Energy has granted $44 million to the consortium, called the National Alliance for Advanced Biofuels and Bioproducts, which also has received $16 million from industry and university groups. Members include 40 universities and research institutions, and the consortium’s work is intended to spur new companies and bolster existing algae fuel makers, such as Sapphire Energy and Solazyme.

Algae biofuels avoid the fuel/food conundrum, as algae can be grown in saltwater or wastewater in the desert and does not displace crops. The biofuel is also a so-called drop-in fuel, meaning it can be used in vehicles and jets without modifiying their engines and can be shipped through existing pipelines.

More than 70,000 types of algae exist, but the consortium’s research is focused on tiny microalgae, which range in size from one micron to 100 microns—about the diameter of human hair. This tiny green goo is a powerhouse; it grows in wastewater around the clock year-round and doubles in size in just hours.

So far, the consortium has screened 2,200 candidates, whittling that number down to the 30 most promising strains of algae. They’ve developed a genetic bar code to quickly assess the lipid content of each type of algae. (Lipids are the fatty acids that can produce oil.) Scientists then genetically tinkered with the best strains to make them grow even faster. One of the research groups spun off a startup, Phenometrics, to build an algae-growing platform to indentify productive strains.

Jose Olivares, a scientist at Los Alamos National Laboratory who runs the consortium, said the tiny algae they’re creating potentially could yield 1,000 gallons to 4,000 gallons per acre per year. That’s five to 10 times more productive than palm oil or corn ethanol and 20 to 100 times more productive than soybeans.

While algae is typically 99 percent water by weight, the strains the scientists are developing contain up to 40 percent lipids by weight. “We need to provide organisms that are robust, and provide the most lipid content possible,” said Olivares.

There are challenges to using algae, however, as harvesting and converting the oily goo to fuel is expensive. To drive down those costs, researchers have developed a technique called hydrothermal liquefaction, which is similar to pressure cooking. The process both extracts the algal oil and converts it to biocrude. “This technology has significant yield improvement over any type of extraction process that we’ve tried so far,” said Olivares.