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Systematic name 1-Butanol
Other names Butanol
Butyl alcohol
Butyric alcohol
Molecular formula C4H10O
Molar mass 74.1216(42) g/mol
Appearance clear liquid
CAS number [71-36-3]
Density and phase 0.8098 g/cm³ @ 20 °C, liquid
Solubility in water 9.1 mL/100 mL H2O at 25 °C
Melting point −89.5 °C (183.7 K)
Index of refraction 1.3993 @ 20 °C
Boiling point 117.73 °C (390.9 K)
Viscosity 3 cP at 25°C
Molecular shape  ?
Crystal structure  ?
Dipole moment 1.52 D (1-butanol)
MSDS External MSDS
Main hazards flammable
NFPA 704
Flash point 37 °C (99 °F)
R/S statement R:R10 R22 R37/38
R41 R67
S: S7/9 S13 S26
S37/39 S46
RTECS number EO1400000
Supplementary data page
Structure and
n, εr, etc.
Phase behaviour
Solid, liquid, gas
Spectral data UV, IR, NMR, MS
Related compounds
Related alcohols Propanol, Pentanol,
Isobutanol, 2-Butanol,
Related compounds Butyraldehyde, Butyric acid,
Except where noted otherwise, data are given for
materials in their standard state (at 25°C, 100 kPa)
Infobox disclaimer and references

Butanol or butyl alcohol (sometimes also called biobutanol when produced biologically), is a primary alcohol with a 4 carbon structure and the molecular formula of C4H10O. It is primarily used as a solvent, as an intermediate in chemical synthesis, and as a fuel. There are four isomeric structures for butanol.



The unmodified term butanol usually refers to the straight chain isomer with the alcohol functional group at the terminal carbon, which is also known as n-butanol or 1-butanol. The straight chain isomer with the alcohol at an internal carbon is sec-butanol or 2-butanol. The branched isomer with the alcohol at a terminal carbon is isobutanol; 2-methyl-1-propanol, and the branched isomer with the alcohol at the internal carbon is tert-butanol; 2-methyl-2-propanol.

n-butanol sec-butanol isobutanol tert-butanol

Butanol isomers, due to their different structures, have somewhat different melting and boiling points. All are moderately miscible in water, less so than ethanol, and more so than the higher (longer carbon chain) alcohols. This is because all alcohols have a hydroxyl group which makes them polar which in turn tends to promote solubility in water. At the same time the carbon chain of the alcohol resists solubility in water. Methanol, ethanol and propanol, are fully miscible in water because the hydroxyl group predominates while butanol is moderately miscible because of the balance between the two opposing solubility trends. Like many alcohols, butanol is toxic.



Main article: Butanol fuel

Butanol is considered as a potential biofuel (butanol fuel). Butanol at 85 percent strength can be used in cars without any change to the engine (unlike ethanol) and it produces more power than ethanol and almost as much power as gasoline.

Other uses

Butanol sees use as a solvent for a wide variety of chemical and textile processes, in organic synthesis and as a chemical intermediate. It is also used as a paint thinner and a solvent in other coating applications where it is used as a relatively slow evaporating latent solvent in lacquers and ambient-cured enamels. It finds other uses such as a component of hydraulic and brake fluids.[1]

It is also used as a base for perfumes, but on its own has a highly alcoholic aroma.

Salts of butanol are chemical intermediates for example alkali metal salts of tert-butanol are tert-butoxides.


Main article: Butanol fuel

Since the 1950s, most butanol in the United States is produced commercially from fossil fuels. The most common process starts with propene, which is run through an hydroformylation reaction to form butanal, which is then reduced with hydrogen to butanol. Butanol can also be produced by fermentation of biomass by bacteria. Prior to the 1950s, Clostridium acetobutylicum was used in industrial fermentation processes producing butanol. Research in the past few decades showed results of other microorganisms that can produce butanol through fermentation.

See also


  • Merck Index, 12th Edition, 1575.
  1. ^ Isobutanol at
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Butanol". A list of authors is available in Wikipedia.
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