Biofuel in The United States - Butanol Fuel

Butanol Fuel

A team of chemical engineers at the University of Arkansas have developed a method for converting common algae into butanol, which can be used as fuel in existing gasoline internal combustible engines. The algae are grown on "raceway" troughs and the algaes growth is enhanced by delivering high concentrations of carbon dioxide through hollow fiber membranes.

Questions have been raised about the amount of energy needed to produce fuel-grade ethanol compared to the amount of energy it releases upon combustion. Depending on who you ask, you may get a different answer as to whether or not ethanol from corn produces more energy than it consumes.

Therefore, companies like BP and DuPont have been looking at the next generation of biofuel, specifically investigating butanol.

Specific advantages to using butanol compared to ethanol include, higher energy content per kg, the ability to be blended at higher concentrations without further adaptation of vehicles, and potential to use existing storage/transport infrastructure.

However, using corn as a feedstock to produce either ethanol or butanol seems infeasible without significant technology improvements regarding yields. Currently, about 2.5 US gallons (9.5 L) of butanol can be produced per bushel of corn (373 l/t). Meanwhile, about 2.75 US gallons (10.4 L) of ethanol can be produced per bushel of corn (410 l/t). Our current production of ethanol is about 5 billion US gallons per year (19×10^6 m3/a), but it requires 20% of the United States' corn crop and only replaces 1% of its petroleum use. Reaching the 36 billion US gallons (140×10^6 m3) biofuel mandate by 2022, would be a difficult task if only using a corn grain feedstock.