Butanol

Butanol or bio-butanol

One day butanol will probably replace ethanol as it is more like oil.

  It carries 15% more energy. Butanol  has 90% of the energy of petrol, ethanol has 70%.
  Less soluble in water than ethanol.
  Can be used directly in petrol engines without any conversion
  Less corrosive than ethanol.
  Ethanol requires special pipelines for shipping, butanol can be shipped in unmodified petrol/gasoline pipelines
  Can be mixed 16% with petrol /gasoline without separation. Ethanol has a 10% maximum limit.
 
There are many organisations developing ways of producing butanol from biomass.
A few claim they are ready, while most are still in the development stage.
It will be a simple matter to convert ethanol production to butanol.

Isomers of butanol

There are 4 different isomers of butanol, and each has slightly different properties. Each process for manufacturing butanol produces a different mix of each isomer.

1-butanol, n-Butanol, butan-1-ol, butyl alcohol, n butyl alcohol, properties

n-butanol is produced naturally in small quantities during the fermentation  of sugar by yeast. Along with other higher alcohols it is called fusel oil and is responsible for some of the flavour and hangover from cheap alcoholic drinks. Fusel oil is a good paint stripper.

Solubility in water: 6 g/100ml. 

 

2-Butanol, butan-2-ol, sec butanol,   properties

solubility in water: 35g/100ml   Wikipedia

 

Iso butanol, 2-methyl-1-propanol, iso butly alcohol, 2-methyl-1-propanol, 2-methylpropan-1-ol  properties

Solubility in water: 8g/100ml
 

Tert-butanol, tert-butyl alcohol, 2-methyl-2-propanol, methylpropan-2-ol  properties

Solubility in water: miscible
 

n butanol  (1 butanol)

2-butanol

There are different ways of portraying organic compounds. The first one in this column is the more accurate as it depicts the true size of the electron clouds. However with more complex molecules it is impossible to see each atom. So the letters or ball and stick methods are more usually used.

sec butanol  (2 butanol)

Iso butanol (2-methylpropan-1-ol)

Tert butanol (2-methylpropan-2-ol)

can be used as an additive but not as a straight fuel as it's MP = 25 oC.

Production of biobutanol

The name biobutanol denotes it is made biologically. Chemically it is the same as butanol made from petroleum,  sometimes referred to as petrobutanol.

As butanol can be made from sugar, it will be quite cheap to convert a standard fermenter from ethanol to butanol.

Fermentation with Clostridium acetobutylicum

The bacterium Clostridium acetobutylicum  ferments sugars in the Acetone-Butanol-Ethanol fermentation (ABE). It has been used since 1916 to make acetone. It also makes twice as much 1-butanol, as acetone, plus other bye-products. The organism dies when the butanol reaches 7%. There is research to improve this. 

Bioproduction of butanol from biomass: from genes to
bioreactors

 

E. Coli producing n-butanol

The bacerium E. Coli has been genetically engineered to produce 1-butanol. Ref..

"produce 15 to 30 grams of n-butanol per liter of culture medium using genetically engineered Escherichia coli "

Researchers engineer E. coli to produce alternative fuel

 

 DuPont and BP plan to make butanol from sugar beet by 2010.

(should be running by now - ed.)

2008

"DuPont Biofuels Venture Manager David Anton and BP Biofuels Business Technology Manager Ian Dobson disclosed that the partnership has been developing biocatalysts to produce 1-butanol as well as 2-butanol and iso-butanol.

 Fuel testing conducted over the last 12 months by BP demonstrates that high octane biobutanol can deliver the exceptional performance characteristics the partnership has previously communicated." Ref...

Butamax

Modified yeast by Gevo

Gevo has modified yeast to produce butanol from sugar.

They also have developed a way of separating the butanol from water.

It should be straight forward to convert an ethanol fermentaion plant to produce butanol.

The Gevo website is vague on details.  

 

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Gevo has used the tools of biotechnology to replace the metabolic pathways in a robust yeast biocatalyst so that instead of making ethanol, the biocatalyst (cell factory) would now make isobutanol. Click on the image to view a larger version.

 

 

 

 

 

 

 

 

 

 

 

Microbial electrosynthesis

The newly discovered  Microbial electrosynthesis  produces butanol from CO2, water and electricity. It is similar to photosynthesis but 10-1,000 time more efficient. Fuels produced by this method are being called "electrofuels".

Geobacter is a bacterial species that uses electric current to convert carbon dioxide into transportation fuels such as butanol.

Cobalt Technologies is piloting the production of Bio butanol though they are vague on the details. "Improved strains of bacteria.."

 

Making butanol is a new research field and needs to catch up with ethanol.

Refs:

Microbial electrosynthesis

Search Microbial electrosynthesis

Heat values of various fuels

Making bio-butanol

Ethanol vs Butanol

Better bugs for brewing butanol

Higher alcohols biorefinery

Bio-butanol evaluation

Geobacter grows on an electrode. The bacteria feeds on electrons, enabling it to "breathe in" carbon dioxide and "exhale" fuels. Image credit: UMass, Geobacter.org.

Research - Conversion of Methane to Butanol

MOgene Green Chemicals is working on a photosynthetic
organism for methane conversion that can use energy from both methane and sunlight.

University of Delaware, Coskata, and the University of California, are working on a very similar projects.

 Source

 

Electrofuels - Projects

 

 

Butanol can also be made by algae, and diatoms.