Isobutanol
Encyclopedia
Isobutanol is an organic compound
with the formula (CH3)2CHCH2OH. This colorless, flammable liquid with a characteristic smell is mainly used as a solvent. Its isomer
s include n-butanol
, 2-butanol
, and tert-butanol
, all of which are more important industrially.
of propylene
. Two methods are practiced industrially, hydroformylation
is more common and generates a mixture of normal and isobutyraldehyde
s, which are hydrogenated to the alcohols and then separated. Reppe carbonylation is also practiced.
Isobutanol is also produced naturally during the fermentation of carbohydrates and may also be a byproduct of the decay process of organic matter. Isobutanol, along with other low molecular weight alcohols can also be produced by some engineered microorganisms such as corynebacterium
. A genetically engineered strain of the bacterium Clostridium cellulolyticum
converted cellulose
to isobutanol via isobutyraldehyde.
Isobutanol could possibly serve as an alternative to gasoline to fuel combustion engines, and it is being produced by companies such as Gevo. A 1993 SAE technical paper addresses blending methanol, ethanol and isobutanol with unleaded gasoline for use as a motor fuel. A similar mixture is being used by Dyson Racing in the 2010 American LeMans Series. Gevo acquired Agri-Energy's Luverne, Minnesota
, ethanol production facility to retrofit it to produce commercial quantities of isobutanol for motor fuel.
In March 2009, the Canadian
government announced a ban on isobutanol use in cosmetics
.
Organic compound
An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon. For historical reasons discussed below, a few types of carbon-containing compounds such as carbides, carbonates, simple oxides of carbon, and cyanides, as well as the...
with the formula (CH3)2CHCH2OH. This colorless, flammable liquid with a characteristic smell is mainly used as a solvent. Its isomer
Isomer
In chemistry, isomers are compounds with the same molecular formula but different structural formulas. Isomers do not necessarily share similar properties, unless they also have the same functional groups. There are many different classes of isomers, like stereoisomers, enantiomers, geometrical...
s include n-butanol
N-Butanol
n-Butanol or n-butyl alcohol or normal butanol is a primary alcohol with a 4-carbon structure and the molecular formula C4H9OH. Its isomers include isobutanol, 2-butanol, and tert-butanol...
, 2-butanol
2-Butanol
2-Butanol, or sec-butanol, is an organic compound with formula CH3CHCH2CH3. This secondary alcohol is a flammable, colorless liquid that is soluble in 12 parts water and completely miscible with polar organic solvents such as ethers and other alcohols. It is produced on a large scale, primarily as...
, and tert-butanol
Tert-Butanol
tert-Butanol, or 2-methyl-2-propanol, is the simplest tertiary alcohol. It is one of the four isomers of butanol. tert-Butanol is a clear liquid with a camphor-like odor. It is very soluble in water and miscible with ethanol and diethyl ether...
, all of which are more important industrially.
Production
Isobutanol is produced by the carbonylationCarbonylation
Carbonylation refers to reactions that introduce carbon monoxide into organic and inorganic substrates. Carbon monoxide is abundantly available and conveniently reactive, so it is widely used as a reactant in industrial chemistry.-Organic chemistry:...
of propylene
Propylene
Propene, also known as propylene or methylethylene, is an unsaturated organic compound having the chemical formula C3H6. It has one double bond, and is the second simplest member of the alkene class of hydrocarbons, and it is also second in natural abundance.-Properties:At room temperature and...
. Two methods are practiced industrially, hydroformylation
Hydroformylation
Hydroformylation, also known as oxo synthesis or oxo process, is an important industrial process for the production of aldehydes from alkenes. This chemical reaction entails the addition of a formyl group and a hydrogen atom to a carbon-carbon double bond...
is more common and generates a mixture of normal and isobutyraldehyde
Isobutyraldehyde
Isobutyraldehyde is the chemical compound with the formula 2CHCHO. It is an aldehyde, isomeric with n-butyraldehyde . Isobutyraldehyde is manufactured, often as a side-product, by the hydroformylation of propene...
s, which are hydrogenated to the alcohols and then separated. Reppe carbonylation is also practiced.
Isobutanol is also produced naturally during the fermentation of carbohydrates and may also be a byproduct of the decay process of organic matter. Isobutanol, along with other low molecular weight alcohols can also be produced by some engineered microorganisms such as corynebacterium
Corynebacterium
Corynebacterium is a genus of Gram-positive rod-shaped bacteria. They are widely distributed in nature and are mostly innocuous. Some are useful in industrial settings such as C. glutamicum. Others can cause human disease. C...
. A genetically engineered strain of the bacterium Clostridium cellulolyticum
Clostridium cellulolyticum
Clostridium cellulolyticum is an anaerobic, motile, gram-positive bacterium....
converted cellulose
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....
to isobutanol via isobutyraldehyde.
Applications
Isobutanol has a variety of technical and industrial applications:- feedstock in the manufacture of isobutyl acetateIsobutyl acetateThe chemical compound isobutyl acetate, also known as 2-methylpropyl ethanoate or β-methylpropyl acetate, is a common solvent. It is produced from the esterification of isobutanol with acetic acid. It is used as a solvent for lacquer and nitrocellulose...
, which is used in the production of lacquerLacquerIn a general sense, lacquer is a somewhat imprecise term for a clear or coloured varnish that dries by solvent evaporation and often a curing process as well that produces a hard, durable finish, in any sheen level from ultra matte to high gloss and that can be further polished as required...
and similar coatingCoatingCoating is a covering that is applied to the surface of an object, usually referred to as the substrate. In many cases coatings are applied to improve surface properties of the substrate, such as appearance, adhesion, wetability, corrosion resistance, wear resistance, and scratch resistance...
s, and in the food industry as a flavouring agent - precursor of derivative esters; isobutyl esterEsterEsters are chemical compounds derived by reacting an oxoacid with a hydroxyl compound such as an alcohol or phenol. Esters are usually derived from an inorganic acid or organic acid in which at least one -OH group is replaced by an -O-alkyl group, and most commonly from carboxylic acids and...
s such as diisobutyl phthalateDiisobutyl phthalateDiisobutyl Phthalate is prepared by esterification process of isobutanol and phthalic anhydride. Its structural formula is C6H42. Refractive index is 1.488 - 1.492 ....
(DIBP) are used as plasticizer agents in plastics, rubbers, and other dispersions - paint solvent
- varnish remover
- ink ingredient
- paint additive, to reduce viscosityViscosityViscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
, improve brush flow, and retard formation of oil residues (blush) on painted surfaces - gasoline additive, to reduce carburetor icingCarburetor icingCarburetor, or carb icing, is an icing condition which can affect any carburetor under certain atmospheric conditions. Carburetor icing occurs when there is humid air, and the temperature drop in the venturi causes the water vapor to freeze. The ice will form on the surfaces of the carburetor...
- automotive polish additive
- automotive paint cleaner additive
- chemical extractant in production of organic compounds
- mobile phase in thin layer chromatography.
Isobutanol could possibly serve as an alternative to gasoline to fuel combustion engines, and it is being produced by companies such as Gevo. A 1993 SAE technical paper addresses blending methanol, ethanol and isobutanol with unleaded gasoline for use as a motor fuel. A similar mixture is being used by Dyson Racing in the 2010 American LeMans Series. Gevo acquired Agri-Energy's Luverne, Minnesota
Luverne, Minnesota
As of the census of 2000, there were 4,617 people, 1,968 households, and 1,247 families residing in the city. The population density was 1,356.1 people per square mile . There were 2,161 housing units at an average density of 634.7 per square mile...
, ethanol production facility to retrofit it to produce commercial quantities of isobutanol for motor fuel.
Safety and regulation
Isobutanol is one of the least toxic of the butanols with an of 2460 mg/kg (rat, oral).In March 2009, the Canadian
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
government announced a ban on isobutanol use in cosmetics
Cosmetics
Cosmetics are substances used to enhance the appearance or odor of the human body. Cosmetics include skin-care creams, lotions, powders, perfumes, lipsticks, fingernail and toe nail polish, eye and facial makeup, towelettes, permanent waves, colored contact lenses, hair colors, hair sprays and...
.