Biobutanol or Biobased Butanol Fuel is second generation alcoholic fuel with a higher energy
density and lower volatility vs. ethanol. Over a dozen companies are focused on developing biobutanol on commercial
scale. This is a true biofuel for masses with potential of little or no impact on food supply and ability to
compete favorably with $80 bbl oil. Effort is focused on both fermentation of sugars, starch and other biomass and
through pyrolysis and reformulation of biomass. The secondary appeal of biobutanol is its variety of
commercial uses in an existing market worth over $5 billion
Biobutanol was first produced via
fermentation a hundred years ago. Over 6.5
billion lbs of butanol are used yearly. Not all biobutanol molecules are
same-isobutanol has different properties vs. n-butanol. Companies like Butamax, Gevo, Colbalt
technologies, Cathay continue to raise millions in funding. Solar
butanol fuel has been produced from CO2.
The following video presents an overview of biobutanol. Let us know your
thoughts and comments.
What is Biobutanol?
which is also sometimes called biogasoline, is an alcohol that is produced from biomass feedstocks. Butanol is
a 4-carbon alcohol that is currently used as an industrial solvent in many wood finishing products. Biobutanol
can be utilized in internal combustion engines as both a gasoline additive and or a fuel blend with gasoline.
The energy content of biobutanol is 10% less than that of regular gasoline. This is not as bad as
energy density of ethanol is 40% lower. Since biobutanol is more chemically similar to
gasoline than ethanol, it can be integrated into regular internal combustion engines easier than ethanol. Its
bioproduction route was halted in the 1960s due to high production price with respect to production from
petroeum. New technology advancements and an increase in petroleum prices are making bioproduction of butanol
more competitive and safer. Biobutanol has displayed the potential to reduce the carbon emissions by 85
percent when compared to gasoline, making it a superior alternative to gasoline and a gasoline-ethanol blended
How is biobutanol made?
is made via fermentation of biomasses from substrates ranging from corn grain, corn stovers and
other feedstocks. Microbes, specifically of the Clostridium acetobutylicum, are introduced to the
sugars produced from the biomass. These sugars are broken down into various alcohols, which include ethanol
and butanol. Unfortunately, a rise in alcohol concentration causes the butanol to be toxic to the
microorganisms, killing them off after a period of time. This made the fermentation process expensive and
unrealistic when compared to the petroleum costs of the late 50’s. Luckily, new technological advances and
the discovery of new microbes have improved the efficiency and cost of the fermentation process tremendously.
Through genetic engineering, researchers have been able to modify the most efficient microbes to be able to
withstand high alcohol concentrations. New modifications are constantly being researched, including the
modification to enzymes and genes involved in butanol formation from biomass fermentation.
A promising trend is a
slew of recent ethanol fermentation plants purchases by biobutanol companies. These ethanol plants are being retrofitted with advanced separation systems to
allow them to produce biobutanol. Since biobutanol has inherently higher value vs. bioethanol, the trend of
the plant conversions is likely to continue.
Aside from fermentation, a handful of companies are
pursuing pyrolysis biobutanol. This route can
convert waste biomass or crop waste into biobutanol.
What are some recent developments for biobutanol?
Aside from the increasing popularity of biobutanol due to its advantages, the percent yield and speed of its
production are dependant partially on the organisms which process the substrates. Efforts are currently underway to
improve the existing microbes used for fermentation. Next major cost hurdle is separation costs of butanol from
fermentation broth--several membrane based separation methods are under investigation which can reduce costs of
biobutanl by 40-50%. Through a mixture of genetic engineering and membrane separation, biobutanol has a promising