NASA is applying space technology to a decidedly down-to-earth effort linking the production of algae-based fuel with an inexpensive method of sewage treatment, according to recent news reports. The space agency is growing algae for biofuel in plastic bags of sewage floating in the ocean.
Just imagine flying your airplane on fuel derived from the contents of all those EAA AirVenture Port-A-Potties. Now, that’s recycling, not to mention experimental aviation.
Jonathan Trent, the lead researcher on the project at NASA’s Ames Research Center in California, said the effort has three goals: to produce biofuels with few resources in a confined area, to help cleanse municipal wastewater, and to sequester carbon dioxide emissions that are produced in the process.
“Algae are the best source of biofuels on the planet that we know about,” Trent said in a New York Times interview. “If we can also clean [wastewater] at the same time we create biofuels, that would great.”
According to Trent, the process is simple. It starts with algae being placed in sewage-filled plastic bags which, in true NASA style, have a catchy acronym: OMEGA, for “offshore membrane enclosures for growing algae.” The OMEGA bags are semi-permeable membranes developed to recycle astronauts’ wastewater on space missions. In Trent’s application, the membranes let freshwater out but keep saltwater from getting in.
The algae in the bag get their nutrients from the sewage, thus cleaning the water and produce fat-soluble molecules that can be converted to fuel, as Trent explained it. The OMEGA bags use water, solar energy and carbon dioxide to produce sugar that algae metabolize into lipids. Oxygen and clean water are released through the membrane and into the ocean.
Suppose the bags leak sewage into the sea? Trent said that salty seawater would kill the algae, preventing the escape of an invasive species. Fine, but what about the sewage?
Well, he said with astonishingly politically-incorrect candor, “the only thing we’re putting in the water is already in the ocean anyway.”
Trent’s technology does face a few challenges, he concedes. He and his fellow researchers haven’t yet found plastic capable of withstanding pounding waves and cold temperatures without becoming too brittle for osmosis, and there is the matter of money. Venture capitalists are wary, Trent said, but his team has had some luck with the California Energy Commission, from which a grant is slated for August, assuming California doesn’t declare bankruptcy in the meantime.
Finally, there’s the calculation that NASA’s sewage bags would have to cover 10 million acres of ocean to produce the 21 billion gallons of fuel needed to make the whole thing financially feasible.
That’s a lot of ocean – and a lot of sewage.