Biofuels from Seaweed
The concept of making biofuels from seaweed has been floating around as an idea for a while now, but this week there were a few real news items about it. Well, I consider it real news when it makes the cover of Science.
Following the theme that any ready source of carbon, not already used for something, is a prime target for biofuel prospectors, scientists are working to create microorganisms that can break down seaweeed alginates into sugar, and then make ethanol from it.
The microbe is our friend E. coli, and researchers at Bio Architecture Lab, a biofuel and renewable chemicals company in Berkeley, Calif. have added genes that allow E. coli to first break down alginates into smaller bits, digest those more sugar-like bits, and then spit out ethanol. Unlike in the processes usually used for cellulosic ethanol, the Science article writers claim their bacteria can chomp seaweed without chemical or heat pre-treatment.
If seaweed as cover model isn’t convincing, a second seaweeed-flavored item announced this week is a new collaboration between enzyme maker Novozymes and an Indian seaweed company called Sea6 Energy. “The research alliance will use enzymes to convert seaweed-based carbohydrates to sugar, which can then be fermented to produce ethanol for fuel, fine chemicals, proteins for food, and fertilizers for plants,” says the press release. (I read that to mean the non-sugar portion would be made into food and fertilizer – if sugar can be made into protein I’m going to have to change my diet).
Here’s the benefits that the seaweed pushers are claiming: seaweed has a high sugar content (presumably after those enzymes get to working), they don’t require irrigation (ha! no kidding) or fertilizer, and of course, duh, they don’t take up cropland. Seaweed – also called macroalgae by some – can be raised and harvested without those fancy bioreactors used by algae-to-fuel operators.
Seaweed can, however, be a purpose-grown crop. In fact, Sea6 already has a supply chain set up for that, as do firms like the chemical company FMC that harvest and process seaweed for the food markets. Alginate and carrageenen are already big business helping to make your low-fat Ranch dressing taste creamy (see Call in the Food Fixers for more on seaweed in your food).
But what works for the high-margin food additives business may not be profitable for the lower-margin fuel industry. Still, it’s an idea that’s spreading.