1-Butanol

Last updated
1-Butanol
Skeletal formula of n-butanol 1-Butanol skeletal.svg
Skeletal formula of n-butanol
Spacefill model of n-butanol Butan-1-ol-3D-vdW.png
Spacefill model of n-butanol
Butan-1-ol Lewis.svg
Names
Preferred IUPAC name
Butan-1-ol [1]
Other names
n-Butanol
n-Butyl alcohol
n-Butyl hydroxide
n-Propylcarbinol
n-Propylmethanol
1-Hydroxybutane
Methylolpropane
Identifiers
3D model (JSmol)
3DMet
969148
ChEBI
ChEMBL
ChemSpider
DrugBank
ECHA InfoCard 100.000.683 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 200-751-6
25753
KEGG
MeSH 1-Butanol
PubChem CID
RTECS number
  • EO1400000
UNII
UN number 1120
  • InChI=1S/C4H10O/c1-2-3-4-5/h5H,2-4H2,1H3 Yes check.svgY
    Key: LRHPLDYGYMQRHN-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C4H10O/c1-2-3-4-5/h5H,2-4H2,1H3
  • OCCCC
Properties
C4H10O
Molar mass 74.123 g·mol−1
AppearanceColourless, refractive liquid
Odor banana-like, [2] harsh, alcoholic and sweet
Density 0.81 g/cm3
Melting point −89.8 °C (−129.6 °F; 183.3 K)
Boiling point 117.7 °C (243.9 °F; 390.8 K)
73 g/L at 25 °C
Solubility very soluble in acetone
miscible with ethanol, ethyl ether
log P 0.839
Vapor pressure 0.58 kPa (20 °C) ILO International Chemical Safety Cards (ICSC)
Acidity (pKa)16.10
−56.536·10−6 cm3/mol
1.3993 (20 °C)
Viscosity 2.573 mPa·s (at 25 °C) [3]
1.66 D
Thermochemistry
Std molar
entropy
(S298)
225.7 J/(K·mol)
−328(4) kJ/mol
−2670(20) kJ/mol
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-acid.svg GHS-pictogram-exclam.svg
NFPA 704 (fire diamond)
NFPA 704.svgHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 3: Liquids and solids that can be ignited under almost all ambient temperature conditions. Flash point between 23 and 38 °C (73 and 100 °F). E.g. gasolineInstability 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g. liquid nitrogenSpecial hazards (white): no code
1
3
0
Flash point 35 °C (95 °F; 308 K)
343 °C (649 °F; 616 K)
Explosive limits 1.45–11.25%
Lethal dose or concentration (LD, LC):
790 mg/kg (rat, oral)
3484 mg/kg (rabbit, oral)
790 mg/kg (rat, oral)
1700 mg/kg (dog, oral) [4]
9221 ppm (mammal)
8000 ppm (rat, 4 h) [4]
NIOSH (US health exposure limits):
PEL (Permissible)
TWA 100 ppm (300 mg/m3) [5]
REL (Recommended)
C 50 ppm (150 mg/m3) [skin] [5]
IDLH (Immediate danger)
1400 ppm [5]
Safety data sheet (SDS) ICSC 0111
Related compounds
Related compounds
Butanethiol
n-Butylamine
Diethyl ether
Pentane
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

1-Butanol, also known as butan-1-ol or n-butanol, is a primary alcohol with the chemical formula C4H9OH and a linear structure. Isomers of 1-butanol are isobutanol, butan-2-ol and tert-butanol. The unmodified term butanol usually refers to the straight chain isomer.

Contents

1-Butanol occurs naturally as a minor product of the ethanol fermentation of sugars and other saccharides [6] and is present in many foods and drinks. [7] [8] It is also a permitted artificial flavorant in the United States, [9] used in butter, cream, fruit, rum, whiskey, ice cream and ices, candy, baked goods, and cordials. [10] It is also used in a wide range of consumer products. [7]

The largest use of 1-butanol is as an industrial intermediate, particularly for the manufacture of butyl acetate (itself an artificial flavorant and industrial solvent). It is a petrochemical derived from propylene. Estimated production figures for 1997 are: United States 784,000 tonnes; Western Europe 575,000 tonnes; Japan 225,000 tonnes. [8]

Production

Since the 1950s, most 1-butanol is produced by the hydroformylation of propene (oxo process) to preferentially form the butyraldehyde n-butanal. Typical catalysts are based on cobalt and rhodium. Butyraldehyde is then hydrogenated to produce butanol.

Propen Hydroformylierung zu Butanol.svg

A second method for producing butanol involves the Reppe reaction of propylene with CO and water: [11]

CH3CH=CH2 + H2O + 2 CO → CH3CH2CH2CH2OH + CO2

In former times, butanol was prepared from crotonaldehyde, which can be obtained from acetaldehyde.

Butanol can also be produced by fermentation of biomass by bacteria. Prior to the 1950s, Clostridium acetobutylicum was used in industrial fermentation to produce butanol. Research in the past few decades showed results of other microorganisms that can produce butanol through fermentation.

Butanol can be produced via furan hydrogenation over Pd or Pt catalyst at high temperature and high pressure.https://pubs.rsc.org/en/content/articlehtml/2014/gc/c3gc41183d

Industrial use

Constituting 85% of its use, 1-butanol is mainly used in the production of varnishes. It is a popular solvent, e.g. for nitrocellulose. A variety of butanol derivatives are used as solvents, e.g. butoxyethanol or butyl acetate. Many plasticizers are based on butyl esters, e.g., dibutyl phthalate. The monomer butyl acrylate is used to produce polymers. It is the precursor to n-butylamines. [11]

Biofuel

1-Butanol has been proposed as a substitute for diesel fuel and gasoline. It is produced in small quantities in nearly all fermentations (see fusel oil). Clostridium produces much higher yields of butanol. Research is underway to increase the biobutanol yield from biomass.

Butanol is considered as a potential biofuel (butanol fuel). Butanol at 85 percent strength can be used in cars designed for gasoline without any change to the engine (unlike 85% ethanol), and it provides more energy for a given volume than ethanol, almost as much as gasoline. Therefore, a vehicle using butanol would return fuel consumption more comparable to gasoline than ethanol. Butanol can also be added to diesel fuel to reduce soot emissions. [12]

The production of, or in some cases, the use of, the following substances may result in exposure to 1-butanol: artificial leather, butyl esters, rubber cement, dyes, fruit essences, lacquers, motion picture, and photographic films, raincoats, perfumes, pyroxylin plastics, rayon, safety glass, shellac varnish, and waterproofed cloth. [7]

Occurrence in nature

Butan-1-ol occurs naturally as a result of carbohydrate fermentation in a number of alcoholic beverages, including beer, [13] grape brandies, [14] wine, [15] and whisky. [16] It has been detected in the volatiles of hops, [17] jack fruit, [18] heat-treated milks, [19] musk melon, [20] cheese, [21] southern pea seed, [22] and cooked rice. [23] 1-Butanol is also formed during deep frying of corn oil, cottonseed oil, trilinolein, and triolein. [24]

Butan-1-ol is one of the "fusel alcohols" (from the German for "bad liquor"), which include alcohols that have more than two carbon atoms and have significant solubility in water. [25] It is a natural component of many alcoholic beverages, albeit in low and variable concentrations. [26] [27] It (along with similar fusel alcohols) is reputed to be responsible for severe hangovers, although experiments in animal models show no evidence for this. [28]

1-Butanol is used as an ingredient in processed and artificial flavorings, [29] and for the extraction of lipid-free protein from egg yolk, [30] natural flavouring materials and vegetable oils, the manufacture of hop extract for beermaking, and as a solvent in removing pigments from moist curd leaf protein concentrate. [31]

Metabolism and toxicity

The acute toxicity of 1-butanol is relatively low, with oral LD50 values of 790–4,360 mg/kg (rat; comparable values for ethanol are 7,000–15,000 mg/kg). [8] [32] [11] It is metabolized completely in vertebrates in a manner similar to ethanol: alcohol dehydrogenase converts 1-butanol to butyraldehyde; this is then converted to butyric acid by aldehyde dehydrogenase. Butyric acid can be fully metabolized to carbon dioxide and water by the β-oxidation pathway. In the rat, only 0.03% of an oral dose of 2,000 mg/kg was excreted in the urine. [33] At sub-lethal doses, 1-butanol acts as a depressant of the central nervous system, similar to ethanol: one study in rats indicated that the intoxicating potency of 1-butanol is about 6 times higher than that of ethanol, possibly because of its slower transformation by alcohol dehydrogenase. [34]

Other hazards

Liquid 1-butanol, as is common with most organic solvents, is extremely irritating to the eyes; repeated contact with the skin can also cause irritation. [8] This is believed to be a generic effect of defatting. No skin sensitization has been observed. Irritation of the respiratory pathways occurs only at very high concentrations (>2,400 ppm). [35]

With a flash point of 35 °C, 1-butanol presents a moderate fire hazard: it is slightly more flammable than kerosene or diesel fuel but less flammable than many other common organic solvents. The depressant effect on the central nervous system (similar to ethanol intoxication) is a potential hazard when working with 1-butanol in enclosed spaces, although the odour threshold (0.2–30 ppm) is far below the concentration which would have any neurological effect. [35] [36]

See also

Related Research Articles

<span class="mw-page-title-main">Alcohol (chemistry)</span> Organic compound with at least one hydroxyl (–OH) group

In chemistry, an alcohol is a type of organic compound that carries at least one hydroxyl functional group bound to a saturated carbon atom. Alcohols range from the simple, like methanol and ethanol, to complex, like sugar alcohols and cholesterol. The presence of an OH group strongly modifies the properties of hydrocarbons, conferring hydrophilic (water-loving) properties. The OH group provides a site at which many reactions can occur.

<span class="mw-page-title-main">Ethanol</span> Organic compound (CH₃CH₂OH)

Ethanol is an organic compound with the chemical formula CH3CH2OH. It is an alcohol, with its formula also written as C2H5OH, C2H6O or EtOH, where Et stands for ethyl. Ethanol is a volatile, flammable, colorless liquid with a characteristic wine-like odor and pungent taste. It is a psychoactive recreational drug, and the active ingredient in alcoholic drinks.

Butanol (also called butyl alcohol) is a four-carbon alcohol with a formula of C4H9OH, which occurs in five isomeric structures (four structural isomers), from a straight-chain primary alcohol to a branched-chain tertiary alcohol; all are a butyl or isobutyl group linked to a hydroxyl group (sometimes represented as BuOH, 1-BuOH, i-BuOH, and t-BuOH). These are 1-butanol, two stereoisomers of sec-butyl alcohol, isobutanol and tert-butyl alcohol. Butanol is primarily used as a solvent and as an intermediate in chemical synthesis, and may be used as a fuel. Biologically produced butanol is called biobutanol, which may be n-butanol or isobutanol.

Fusel alcohols or fuselol, also sometimes called fusel oils in Europe, are mixtures of several higher alcohols produced as a by-product of alcoholic fermentation. The word Fusel is German for "bad liquor".

<span class="mw-page-title-main">Ethyl acetate</span> Organic compound (CH₃CO₂CH₂CH₃)

Ethyl acetate is the organic compound with the formula CH3CO2CH2CH3, simplified to C4H8O2. This colorless liquid has a characteristic sweet smell and is used in glues, nail polish removers, and in the decaffeination process of tea and coffee. Ethyl acetate is the ester of ethanol and acetic acid; it is manufactured on a large scale for use as a solvent.

<span class="mw-page-title-main">2-Butanol</span> Secondary alcohol

Butan-2-ol, or sec-butanol, is an organic compound with formula CH3CH(OH)CH2CH3. Its structural isomers are 1-butanol, isobutanol, and tert-butanol. 2-Butanol is chiral and thus can be obtained as either of two stereoisomers designated as (R)-(−)-butan-2-ol and (S)-(+)-butan-2-ol. It is normally encountered as a 1:1 mixture of the two stereoisomers — a racemic mixture.

<i>tert</i>-Butyl alcohol Chemical compound

tert-Butyl alcohol is the simplest tertiary alcohol, with a formula of (CH3)3COH (sometimes represented as t-BuOH). Its isomers are 1-butanol, isobutanol, and butan-2-ol. tert-Butyl alcohol is a colorless solid, which melts near room temperature and has a camphor-like odor. It is miscible with water, ethanol and diethyl ether.

<span class="mw-page-title-main">Isobutanol</span> Chemical compound

Isobutanol (IUPAC nomenclature: 2-methylpropan-1-ol) is an organic compound with the formula (CH3)2CHCH2OH (sometimes represented as i-BuOH). This colorless, flammable liquid with a characteristic smell is mainly used as a solvent either directly or as its esters. Its isomers are 1-butanol, 2-butanol, and tert-butanol, all of which are important industrially.

<span class="mw-page-title-main">Butyl acetate</span> Chemical compound

n-Butyl acetate is an organic compound with the formula CH3CO2(CH2)3CH3. A colorless, flammable liquid, it is the ester derived from n-butanol and acetic acid. It is found in many types of fruit, where it imparts characteristic flavors and has a sweet smell of banana or apple. It is used as an industrial solvent.

<span class="mw-page-title-main">1-Propanol</span> Primary alcohol compound

1-Propanol is a primary alcohol with the formula CH3CH2CH2OH and sometimes represented as PrOH or n-PrOH. It is a colourless, water-miscible liquid. It is an isomer of 2-propanol. 1-Propanol is used as a solvent.

<i>tert</i>-Butyl acetate Chemical compound

tert-Butyl acetate, t-butyl acetate or TBAc is a colorless flammable liquid with a camphor- or blueberry-like smell. It is used as a solvent in the production of lacquers, enamels, inks, adhesives, thinners and industrial cleaners. It has recently gained EPA volatile organic compound (VOC) exempt status.

<i>sec</i>-Butyl acetate Chemical compound

sec-Butyl acetate, or s-butyl acetate, is an ester commonly used as a solvent in lacquers and enamels, where it is used in the production of acyclic polymers, vinyl resins, and nitrocellulose. It is a clear flammable liquid with a sweet smell.

<span class="mw-page-title-main">Isoamyl alcohol</span> Chemical compound

Isoamyl alcohol is a colorless liquid with the formula C
5
H
12
O
, specifically (H3C–)2CH–CH2–CH2–OH. It is one of several isomers of amyl alcohol (pentanol). It is also known as isopentyl alcohol, isopentanol, or (in the IUPAC recommended nomenclature) 3-methyl-butan-1-ol. An obsolete name for it was isobutyl carbinol.

<span class="mw-page-title-main">2-Ethylhexanol</span> Chemical compound

2-Ethylhexanol is an organic compound with the chemical formula CH3CH2CH2CH2CH(CH2CH3)CH2OH. It is a branched, eight-carbon chiral alcohol. It is a colorless liquid that is poorly soluble in water but soluble in most organic solvents. It is produced on a large scale (>2,000,000,000 kg/y) for use in numerous applications such as solvents, flavors, and fragrances and especially as a precursor for production of other chemicals such as emollients and plasticizers. It is encountered in plants, fruits, and wines. The odor has been reported as "heavy, earthy, and slightly floral" for the R enantiomer and "a light, sweet floral fragrance" for the S enantiomer.

<span class="mw-page-title-main">Butane-1-thiol</span> Chemical compound

Butane-1-thiol, also known as butyl mercaptan, is a volatile, clear to yellowish liquid with a fetid odor, commonly described as "skunk" odor. In fact, 1-butanethiol is structurally similar to several major constituents of a skunk's defensive spray but is not actually present in the spray. The scent of 1-butanethiol is so strong that the human nose can easily detect it in the air at concentrations as low as 10 parts per billion. The threshold level for 1-butanethiol is reported as 1.4 ppb

<span class="mw-page-title-main">Acetone–butanol–ethanol fermentation</span> Chemical process

Acetone–butanol–ethanol (ABE) fermentation, also known as the Weizmann process, is a process that uses bacterial fermentation to produce acetone, n-butanol, and ethanol from carbohydrates such as starch and glucose. It was developed by chemist Chaim Weizmann and was the primary process used to produce acetone, which was needed to make cordite, a substance essential for the British war industry during World War I.

<i>tert</i>-Amyl alcohol Chemical compound

tert-Amyl alcohol (TAA) or 2-methylbutan-2-ol (2M2B), is a branched pentanol.

Isopropyl alcohol is a colorless, flammable organic compound with a pungent alcoholic odor.

<span class="mw-page-title-main">2-Methyl-1-butanol</span> Chemical compound

2-Methyl-1-butanol (IUPAC name, also called active amyl alcohol) is an organic compound with the formula CH3CH2CH(CH3)CH2OH. It is one of several isomers of amyl alcohol. This colorless liquid occurs naturally in trace amounts and has attracted some attention as a potential biofuel, exploiting its hydrophobic (gasoline-like) and branched structure. It is chiral.

Butyl acrylate is an organic compound with the formula C4H9O2CCH=CH2. A colorless liquid, it is the butyl ester of acrylic acid. It is used commercially on a large scale as a precursor to poly(butyl acrylate). Especially as copolymers, such materials are used in paints, sealants, coatings, adhesives, fuel, textiles, plastics, and caulk.

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