Weird Science: Energy from
Scotch Whiskey?
In this issue we will talk about the
possibility of obtaining biofuels from scotch
whiskey. Researchers in the University of
Napier discovered that when they mix subproducts from malt fermentation like the
“pot ale” (liquid residue on top of the pots)
and “draft” (solid residue from the seeds),
they can obtain ethanol, butanol and
propanone (acetone) from a second
fermentation.
The mechanism consists of a simple alcoholic
fermentation where the bacteria from the
Clostridium species begin its vital metabolic
process: ABE fermentation that gives as main
product Butanol (C4H9OH), and as sub-products
Acetone (C3H6O, IUPAC name 2-propanone), and
Ethanol (C2H5OH), from simple sugars such as
glucose.
Why to use biofuels such as butanol?
It can provide as much energy as common gasoline (29,2
MJ/L for butanol and 32 MJ/L for gasoline), mixed with
small amounts of common fuels, bio-butanol can replace
gasoline without needing to change the design of the
engines because it is less corrosive than ethanol (widely
used in Brazil and the US).
Is it viable?
Only in Scotland, 1600 million litres of “pot ale” and 500.000 tons of “draft” are
produced. These two have a very low economic value, so the production of
bio-fuels in big terms was considered by the National Geographic as valuable,
and quoting their article: “this enterprise is determined to demonstrate that
alcohol ad driving are not a bad couple”.