With the message starting to get out about ethanol as an alternative fuel not necessarily being all that it was cracked up to be environmentally or economically speaking, Biobutanol may soon take center stage.
While still derived from food crops at this point in time, Biobutanol is supposedly nearly as efficient as gasoline, wheras ethanol can only achieve 70% efficiency. Biobutanol can also be transported through pipelines and be mixed with gasoline in higher percentages than ethanol can.
While the technology to create Biobutanol has been around for many decades, the costs to produce it were prohibitive; but Dupont and BP recently announced development of technology to make Biobutanol production commercially viable.
The diversion of food into fuel production really, really bugs me, as does the thought of more deforestation in order to power combustion engines, but Dupont claims that they expect to be able to create Biobutanol from grasses and agricultural waste such as straw and corn stalks in the future.
The idea of biodiesel from algae still appeals to me more than ethanol or Biobutanol, although if plant waste can be used for producing Biobutanol, then it could certainly become a small part of the answer to our future fuel needs.