An interesting premise...
Bio Architecture Lab is claiming to have a pilot plant that now converts sugars in seaweed to into isobutanol.
They have been published up in
science.
They claim a conversion of 80% of the maximum theoretical yield from the sugar composition in macro algae (seaweed).
....snip....
January 19, 2012, Berkeley, Calif. – A team of scientists from Bio Architecture Lab (BAL), has developed breakthrough technology that helps to further enable the wide-scale use of seaweed (macroalgae) as a feedstock for advanced biofuels and renewable chemical production. The team engineered a microbe to extract the sugars in seaweed and convert them into renewable fuels and chemicals, thus making seaweed a real renewable biomass contender.
....snip...
The thinking is that this is good, as it does not waste land for growing fuel crop... hopefully no one starts raping the ocean and ripping out all the seaweed.
But Seaweed is fast growing, and ideally can be harvested/grown with minimal impact.