Algae into Fuel
November 10, 2012
There are lots of reports on this around the web. This one is more recent, and notable for the sobering estimate of the amount of land needed to grow sufficient algae to provide our liquid fuels.
One reason why its more likely future transportation needs will be met by diverse solutions, with more mass transit and electrification of cars, for instance, and exotic fuels like algae going for purposes like aviation, where, barring some breakthrough, electric solutions are difficult to envision.
Researchers from University of Michigan have developed a way to “pressure cook” algae for as little as one minute and transform up to 65 percent of the algae into biocrude. Phil Savage, a professor of chemical engineering at U of M, said the research team is trying to mimic the process nature uses when creating crude oil, and his algae of choice is green marine micro-alga.
To make their one-minute biocrude, Savage and Julia Faeth, a doctoral student in Savage’s lab, filled a steel pipe connector with 1.5 milliliters of wet algae, capped it and plunged it into 1,100-degree Fahrenheit sand. The small volume ensured that the algae was heated through. Previously the team heated the algae from 10 to 90 minutes and saw the best results when treating the algae for 10 to 40 minutes at 570 degrees. A small batch of algae can reach this temperature in one minute.
Savage and Faeth aren’t sure why the one-minute results so much better until they do more experiments. “My guess is that the reactions that produce biocrude are actually must faster than previously thought,” Savage surmised. Yet Faeth suggests that the fast heating might boost the biocrude by keeping unwanted reactions at bay. “For example, the biocrude might decompose into substances that dissolve in water, and the fast heating rates might discourage that reaction,” Faeth said.