WASHINGTON — Imagine driving up to a gas station for ethanol made not from corn farms in the heartland but from seaweed farms on the coasts.
Futuristic, yes. But as the world looks for ways to reduce the use of fossil fuels, farming for seaweed as a fuel feedstock could emerge as an option. It's already starting in the earliest stages of testing in Chile.
On Thursday, a breakthrough in the development of biofuels and useful chemicals from seaweed made the cover of Science magazine. The story tells how scientists from Bio Architecture Lab in Berkeley, Calif., engineered a microbe that can convert the sugars in brown, inedible seaweed into energy.
Efforts to develop biofuels from land plants other than corn and sugar have run into the difficulty of finding an economical way to break down the part of the plant that gives it structure — lignin — and use its sugars to make fuel.
Seaweed doesn't have any lignin, but it has another substance that locks up sugars — alginate. Bio Architecture Lab's breakthrough was engineering a microbe to extract sugars from alginate and convert them into fuels and chemicals.
"In the oil industry, oil wells are black wells in the ocean. We spend billions of dollars on refineries to convert that feedstock into usable fuel or chemicals," said the company's CEO, Daniel Trunfio, a retired Royal Dutch Shell executive.
"There's really no difference. Our wells are in the ocean also, but they're green and renewable," Trunfio said.
Like other biofuels, however, seaweed would need space. The company estimates that 3 percent of the world's coasts where kelp grows could be used to make enough ethanol to replace 60 billion gallons of fossil fuel. That's about 4 percent of global transportation fuel demand.
Seaweed farms also would compete with other uses of the coasts, such as conservation, aquaculture, fishing, recreation and possibly other future forms of renewable energy such as offshore wind and tidal and wave energy.
Trunfio said seaweed ethanol would have lower greenhouse gas emissions than gasoline.
Trunfio said that while his company's advance "has game-changing potential," it still has many more steps ahead, including building a pilot plant in Chile, figuring out what products to make, and commercializing them.