ODU experiment on turning sewage into algae-based biodiesel is flourishing

NORFOLK

The tanks are up and running and the slime is growing nicely – thick and green, just the way algae should be.

Friday was a good day to be on the roof of the local sewage plant, where scientists from Old Dominion University were all smiles as they inspected their promising experiment for turning algae into biodiesel fuel.

“Look at the color,” said Margaret Mulholland, an ODU professor, pointing to emerald-green slime growing in plastic tanks filled with treated sewage. “Just wait until this summer. It’ll be a darker green, and in clumps.”

Why not be excited? Their pilot project is cited by the governor whenever he talks about alternative energy in Virginia; state and national media have picked up on the story; the Pentagon is interested; potential investors are calling.

In this era of clean and renewable energy development, researchers at other universities are conducting similar experiments with algae and biofuels. But ODU is on a slightly different and potentially important path, using municipal sewage to generate its slimy fuel supply.

Their first experiment is being conducted atop a sewage treatment plant run by the Hampton Roads Sanitation District, next door to ODU.

The timing could not be better. Virginia, like its neighboring states, is under pressure to reduce nutrient pollution now choking the Chesapeake Bay, and much of the excessive nitrogen and phosphorus comes from sources that include factories, slaughterhouses and sewage plants.

So, conceivably, the ODU technology could kill several birds with one stone. Nutrient-rich wastewater from agriculture, industry and municipal sewage could be piped to and purged at algae-growing stations. Biofuels could be produced. And less nitrogen and phosphorus would enter the Bay.

Add one other side benefit: a reduction in greenhouse gases. Algae love to eat carbon dioxide.

So the ODU scientists think that if carbon emissions spewed by power plants could instead be captured and fed to their algae, the project could help fight global warming.

The pilot project atop the local plant, at best, could generate about 200 gallons of biodiesel a day, worth an estimated $600,000 a year.

“Granted, that’s not a lot,” said Patrick Hatcher, the project leader and an ODU professor of chemistry and biochemistry. “But if you consider that this could be done at sewage plants across the country, then you’re talking about a big, big thing.”

The algae project received about $500,000 last year from state coffers – the most money dedicated to a state-aided research of alternative energies.

Gov. Timothy M. Kaine, who says he keeps a small bottle of algae-based fuel on his desk, has proposed increasing state funds for this and other green research to $2.3 million over the next two years.

Hatcher hopes to push that total to $4.8 million, and he is scheduled to urge lawmakers to do so when he testifies next week before General Assembly money committees.

Also next week, ODU scientists will meet with board members of the Hampton Roads Sanitation District to chart just how far both parties want to pursue their sewage-to-algae partnership.

Hatcher said ODU already is joining hands with other universities to take advantage of the Defense Department’s interest in developing algae-based, alternative jet fuels.

The Pentagon does not want to pay more than $1.50 per gallon of green jet fuel.

Hatcher hopes that, if the government can get financial credits for reducing nutrient pollution by embracing sewage-grown algae, their proposal might just fly.

For now, the experiment is awaiting warmer weather, when algae can grow faster and thicker.

A graduate student checks the tanks on the roof almost every day, sampling the sewage and measuring algae growth. Harvesting of mature slime is expected to start soon, as early as next week, said Andrew Gordon, a biology professor working on the project.

Gordon was on the rooftop Friday, describing the harvesting process.

After about three days in the growing tanks, the algae will be scooped from the last container with a fine-mesh bag. They will be air-dried until they resemble a small cake, then blasted into a high-temperature converter, which captures the natural oils within algae and creates the biodiesel.

“We know we can do it; we’re making biodiesel now,” Hatcher said. “The real question is how far this technology can go.”

Scott Harper, (757) 446-2340, scott.harper@pilotonline.com