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ChAP: Biofuel from aquatic algae

  • Green energy
    Green energy  Elizabeth Canuel and Emmett Duffy inspect the algal flowway at VIMS. (Photo by Stephen Salpukas)  
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What we want to do,” Emmett Duffy said, gesturing toward the first slide of his projected PowerPoint, “is to take pollution and turn it into fuel, on a large, economically competitive scale.”

Duffy was addressing a gathering of a couple dozen scientists, engineers and industrialists gathered in the Alumni House in January to discuss how to make biofuel from algae—and how to make it profitable. Algae-based biofuel is a hot research topic. There are a number of ongoing investigative projects across the country, virtually all of them based on the cultivation of a monoculture—one or another single species of algae, sometimes genetically engineered strains. But Duffy was talking about something completely different: making fuel using the wild algae naturally growing in waterways.

In late September, the project became known as ChAP—the Chesapeake Algae Project—after William & Mary and its Virginia Institute of Marine Science signed a formal agreement with a number of partners, notably Statoil, a Norwegian energy firm that has agreed to seed ChAP to the tune of $3 million. Other key partners are the Williamsburg energy advisory firm Blackrock Energy, the University of Maryland, the Smithsonian Institution, the University of Arkansas and HydroMentia, a Florida company that works with water-treatment technologies.

Duffy, the Loretta and Lewis Glucksman Professor of Marine Science at VIMS, is only one of the researchers involved in ChAP. Duffy and Professor of Marine Science Elizabeth Canuel have been cultivating algae in a flowway at the VIMS Gloucester Point campus for months.

Duffy pointed out that ChAP’s use of wild algae has a number of advantages over other biofuel approaches. For one thing, they sequester, rather than release, nutrients and carbon. “Rather than creating an environmental problem—as we’ve seen in corn ethanol production—they solve an environmental problem,” he explained.

As Dennis Manos sees it, algal biofuel could be part of the answer to the question posed by the world’s appetite for petroleum.

“We would like to help companies put a significant dent in the world’s thousand-barrel-per-second appetite for oil,” said Manos, William & Mary’s V.P. for research.

ChAP differs from other algal biofuel initiatives in two ways.

“In the first place, we’re going to work with many species of algae, as opposed to concentrating on farming a monoculture, or attempting to contain genetically modified algae in open-water environments,” Manos said. He explained that using a polyculture approach makes the algae less susceptible to disease and generally more robust.

“Nature has spent three billion years perfecting the right algal strains for a particular set of conditions,” Duffy added. “We want to use that natural engineering, and that’s what sets this project apart from others.”

The other difference is that the process is designed to work without competing with either fresh-water supplies or agricultural resources. “The process will work in brackish water, salt water, even waste water,” Manos said. “That’s one of the best parts of the whole idea, and ultimately, while producing affordable transportation fuel, using wild algae can even help to remediate conditions that otherwise would lead to harmful algal blooms.”

ChAP will integrate the work of researchers at VIMS with those on the Williamsburg campus of William & Mary. In Williamsburg, Gene Tracy, Chancellor Professor of Physics and Applied Science; Bill Cooke, professor of physics; and Robert Hinkle, associate professor of chemistry, are lead members of the team, which includes other faculty members.

Considered as a replacement for petroleum, an individual alga is basically a bag of oil supported by a skeleton or shell. Different species of algae considerably in lipid content, which essentially means how much of the algae is oil. Elizabeth Canuel points out that lipid content among algal species can vary from 5 to 50 percent. In that way, algae are not unlike different varieties of food crops like corn or potatoes, Manos said.

“Something that does just fine on the Aran Islands west of Ireland would barely be recognized as a potato by a farmer in Idaho,” he explained. “And likewise, McDonald’s isn’t going to make french fries out of the little potatoes from Peru.” Farmers have had thousands of years of experience with food crops to sort out what variety is suitable for different applications, but for ChAP, the learning curve necessarily is going to be a bit steeper.

Early samplings from the flowway at VIMS show many algal species. But the samples are dominated by a single species of diatomaceous algae, a group known for the symmetrical beauty of their skeletons under a microscope, but as Manos says, “not particularly brilliant as a feedstock for fuel, largely because they have so much skeletal material.”

Even if the wild, abundant—yet bony—diatoms aren’t ideal little bags of oil, they do offer some benefits: “They pay you back by growing very rapidly. So a low shell-to-lipid ratio is often made up for by the rate of growth,” Manos said. “If I can grow three grams of something that’s half as efficient in the time it takes you to grow one gram of something that’s perfectly efficient, I still win.”

Much of the early work of ChAP is focused on growth, harvest and identification of available algal species. At the same time, other members of the team are examining a number of possible biofuel production scenarios. It’s a complex problem, beginning with any number of algal species that can serve as feedstock and ending with any of a number of target fuels—butanol, biodiesel, gasoline additives or even an algae-based substitute for jet fuel.

“What we make is going to depend critically on pairing the demand for the product with the suitability of the feedstock we’re working with,” Manos explained. “And also, is there a process to reach that particular target fuel from that particular feedstock?”

Corporate partners Statoil and Blackrock Energy will provide “an immediate link to the market” of any product developed through the initiative, Manos said.

The project was initiated by exploring, among others, technology originally developed by Walter Adey of the Smithsonian Institution as a large-scale aquarium filter.  Adey has been meeting with a group of researchers at William & Mary and VIMS for the past year, working out details of how to adapt the concept to industrial-scale algae cultivation. A test site has been operating at VIMS, using brackish York River water, and a second test station is planned for Lake Matoaka on the William & Mary campus.  i