1-Hexene

Last updated
1-Hexene
1-hexene.svg
1-Hexene-3D-balls.png
Names
Preferred IUPAC name
Hex-1-ene
Other names
Hexene, Hexylene, Butyl ethylene
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.008.868 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 209-753-1
PubChem CID
RTECS number
  • MP6670000
UNII
UN number 2370
  • InChI=1S/C6H12/c1-3-5-6-4-2/h3H,1,4-6H2,2H3 Yes check.svgY
    Key: LIKMAJRDDDTEIG-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C6H12/c1-3-5-6-4-2/h3H,1,4-6H2,2H3
    Key: LIKMAJRDDDTEIG-UHFFFAOYAY
  • C=CCCCC
  • CCCCC=C
Properties
C6H12
Molar mass 84.162 g·mol−1
AppearanceColorless liquid
Density 0.673 g/cm3
Melting point −139.8 °C (−219.6 °F; 133.3 K)
Boiling point 63 °C (145 °F; 336 K)
Insoluble
Viscosity 0.51 cP (0.51 mPa·s) at 28°C
Hazards
GHS labelling:
GHS-pictogram-flamme.svg GHS-pictogram-exclam.svg GHS-pictogram-silhouette.svg
Warning
H225, H304, H319
P210, P233, P240, P241, P242, P243, P264, P280, P301+P310, P303+P361+P353, P305+P351+P338, P331, P337+P313, P370+P378, P403+P235, P405, P501
Safety data sheet (SDS) External MSDS
Supplementary data page
1-Hexene (data page)
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-Hexene (hex-1-ene) is an organic compound with the formula C6H12. It is an alkene that is classified in industry as higher olefin and an alpha-olefin, the latter term meaning that the double bond is located at the alpha (primary) position, endowing the compound with higher reactivity and thus useful chemical properties. 1-Hexene is an industrially significant linear alpha olefin. 1-Hexene is a colourless liquid.

Contents

Production

1-Hexene is commonly manufactured by two general routes: (i) full-range processes via the oligomerization of ethylene and (ii) on-purpose technology. A minor route to 1-hexene, used commercially on smaller scales, is the dehydration of hexanol. Prior to the 1970s, 1-hexene was also manufactured by the thermal cracking of waxes. Linear internal hexenes were manufactured by chlorination/dehydrochlorination of linear paraffins. [1]

"Ethylene oligomerization" combines ethylene molecules to produce linear alpha-olefins of various chain lengths with an even number of carbon atoms. This approach result in a distribution or “full range” of alpha-olefins. The Shell higher olefin process (SHOP) employs this approach. Linde and SABIC have developed the α-SABLIN technology using the oligomerization of ethylene to produce 21 percent 1-hexene. CP Chemicals and Innovene also have full-range processes. Typically, 1-hexene content ranges from about twenty percent distribution in the Ethyl (Innovene) process, whereas only twelve percent of distribution in the CP Chemicals and Idemitsu processes.

An on purpose route to 1-hexene using ethylene trimerization was first brought on stream in Qatar in 2003 by Chevron-Phillips. A second plant was scheduled to start in 2011 in Saudi Arabia and a third planned for 2014 in the US. [2] The Sasol process is also considered an on-purpose route to 1-hexene. Sasol commercially employs Fischer–Tropsch synthesis to make fuels from synthesis gas derived from coal. The synthesis recovers 1-hexene from the aforementioned fuel streams, where the initial 1-hexene concentration cut may be 60% in a narrow distillation, with the remainder being vinylidenes, linear and branched internal olefins, linear and branched paraffins, alcohols, aldehydes, carboxylic acids, and aromatic compounds. The trimerization of ethylene by homogeneous catalysts has been demonstrated. [3] An alternative on-purpose route has been reported by Lummus Technology. [4]

Applications

The primary use of 1-hexene is as a comonomer in production of polyethylene. High-density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) use approximately 2–4% and 8–10% of comonomers, respectively.

Another significant use of 1-hexene is the production of the linear aldehyde heptanal via hydroformylation (oxo synthesis). Heptanal can be converted to the short-chain fatty acid heptanoic acid or the alcohol heptanol.

The chemical is used in the synthesis of flavors, perfumes, dyes and resins.

Hazards

1-Hexene is considered dangerous because in liquid and vapor form it is highly flammable and may be fatal if swallowed and enters airways.

The widespread use of 1-hexene may result in its release to the environment through various waste streams. The substance is toxic to aquatic organisms. [5]

Related Research Articles

<span class="mw-page-title-main">Alkene</span> Hydrocarbon compound containing one or more C=C bonds

In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond.

<span class="mw-page-title-main">Ethylene</span> Hydrocarbon compound (H2C=CH2)

Ethylene is a hydrocarbon which has the formula C2H4 or H2C=CH2. It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene.

<span class="mw-page-title-main">Wax</span> Class of organic compounds which are malleable at room temperature

Waxes are a diverse class of organic compounds that are lipophilic, malleable solids near ambient temperatures. They include higher alkanes and lipids, typically with melting points above about 40 °C (104 °F), melting to give low viscosity liquids. Waxes are insoluble in water but soluble in organic, nonpolar solvents. Natural waxes of different types are produced by plants and animals and occur in petroleum.

<span class="mw-page-title-main">Petrochemical</span> Chemical product derived from petroleum

Petrochemicals are the chemical products obtained from petroleum by refining. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as maize, palm fruit or sugar cane.

<span class="mw-page-title-main">Polyethylene</span> The most common thermoplastic polymer

Polyethylene or polythene is the most commonly produced plastic. It is a polymer, primarily used for packaging. As of 2017, over 100 million tonnes of polyethylene resins are being produced annually, accounting for 34% of the total plastics market.

Butene, also known as butylene, is an alkene with the formula C4H8. The word butene may refer to any of the individual compounds. They are colourless gases that are present in crude oil as a minor constituent in quantities that are too small for viable extraction. Butene is therefore obtained by catalytic cracking of long-chain hydrocarbons left during refining of crude oil. Cracking produces a mixture of products, and the butene is extracted from this by fractional distillation.

A post-metallocene catalyst is a kind of catalyst for the polymerization of olefins, i.e., the industrial production of some of the most common plastics. "Post-metallocene" refers to a class of homogeneous catalysts that are not metallocenes. This area has attracted much attention because the market for polyethylene, polypropylene, and related copolymers is large. There is a corresponding intense market for new processes as indicated by the fact that, in the US alone, 50,000 patents were issued between 1991-2007 on polyethylene and polypropylene.

In organic chemistry, hexene is a hydrocarbon with the chemical formula C6H12. The prefix "hex" is derived from the fact that there are 6 carbon atoms in the molecule, while the "-ene" suffix denotes that there is an alkene present—two carbon atoms are connected via a double bond. There are several isomers of hexene, depending on the position and geometry of the double bond in the chain. One of the most common industrially useful isomers is 1-hexene, an alpha-olefin. Hexene is used as a comonomer in the production of polyethylene.

<span class="mw-page-title-main">Linear low-density polyethylene</span>

Linear low-density polyethylene (LLDPE) is a substantially linear polymer (polyethylene), with significant numbers of short branches, commonly made by copolymerization of ethylene with longer-chain olefins. Linear low-density polyethylene differs structurally from conventional low-density polyethylene (LDPE) because of the absence of long chain branching. The linearity of LLDPE results from the different manufacturing processes of LLDPE and LDPE. In general, LLDPE is produced at lower temperatures and pressures by copolymerization of ethylene and such higher alpha-olefins as butene, hexene, or octene. The copolymerization process produces an LLDPE polymer that has a narrower molecular weight distribution than conventional LDPE and in combination with the linear structure, significantly different rheological properties.

A polyolefin is a type of polymer with the general formula (CH2CHR)n where R is an alkyl group. They are usually derived from a small set of simple olefins (alkenes). Dominant in a commercial sense are polyethylene and polypropylene. More specialized polyolefins include polyisobutylene and polymethylpentene. They are all colorless or white oils or solids. Many copolymers are known, such as polybutene, which derives from a mixture of different butene isomers. The name of each polyolefin indicates the olefin from which it is prepared; for example, polyethylene is derived from ethylene, and polymethylpentene is derived from 4-methyl-1-pentene. Polyolefins are not olefins themselves because the double bond of each olefin monomer is opened in order to form the polymer. Monomers having more than one double bond such as butadiene and isoprene yield polymers that contain double bonds (polybutadiene and polyisoprene) and are usually not considered polyolefins. Polyolefins are the foundations of many chemical industries.

<span class="mw-page-title-main">Alpha-olefin</span> Hydrocarbon compounds with a C=C bond at the alpha carbon

In organic chemistry, alpha-olefins are a family of organic compounds which are alkenes with a chemical formula CxH2x, distinguished by having a double bond at the primary or alpha (α) position. This location of a double bond enhances the reactivity of the compound and makes it useful for a number of applications.

<span class="mw-page-title-main">Linear alpha olefin</span>

Linear alpha olefins (LAO) or normal alpha olefins (NAO) are olefins or alkenes with a chemical formula CxH2x, distinguished from other mono-olefins with a similar molecular formula by linearity of the hydrocarbon chain and the position of the double bond at the primary or alpha position.

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

1-Butene (or 1-Butylene) is the organic compound with the formula CH3CH2CH=CH2. It is a colorless gas that is easily condensed to give a colorless liquid. It is classified as a linear alpha-olefin. It is one of the isomers of butene (butylene). It is a precursor to diverse products.

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

1-Octene is an organic compound with a formula CH2CHC6H13. The alkene is classified as a higher olefin and alpha-olefin, meaning that the double bond is located at the alpha (primary) position, endowing this compound with higher reactivity and thus useful chemical properties. 1-Octene is one of the important linear alpha olefins in industry. It is a colourless liquid.

The Shell higher olefin process (SHOP) is a chemical process for the production of linear alpha olefins via ethylene oligomerization and olefin metathesis invented and exploited by Royal Dutch Shell. The olefin products are converted to fatty aldehydes and then to fatty alcohols, which are precursors plasticizers and detergents. The annual global production of olefines through this method is over one million tonnes.

Decene is an organic compound with the chemical formula C10H20. Decene contains a chain of ten carbon atoms with one double bond, making it an alkene. There are many isomers of decene depending on the position and geometry of the double bond. Dec-1-ene is the only isomer of industrial importance. As an alpha olefin, it is used as a comonomer in copolymers and is an intermediate in the production of epoxides, amines, oxo alcohols, synthetic lubricants, synthetic fatty acids and alkylated aromatics.

<span class="mw-page-title-main">Concurrent tandem catalysis</span>

Concurrent tandem catalysis (CTC) is a technique in chemistry where multiple catalysts produce a product otherwise not accessible by a single catalyst. It is usually practiced as homogeneous catalysis. Scheme 1 illustrates this process. Molecule A enters this catalytic system to produce the comonomer, B, which along with A enters the next catalytic process to produce the final product, P. This one-pot approach can decrease product loss from isolation or purification of intermediates. Reactions with relatively unstable products can be generated as intermediates because they are only transient species and are immediately used in a consecutive reaction.

<span class="mw-page-title-main">Chromium(III) 2-ethylhexanoate</span> Chemical compound

Chromium(III) 2-ethylhexanoate, C24H45CrO6, is a coordination complex of chromium and ethylhexanoate. In combination with 2,5-dimethylpyrrole it forms the Phillips selective ethylene trimerisation catalyst (not to be confused with Phillips catalyst), used in the industrial production of linear alpha olefins, particularly 1-hexene or 1-octene.

In organic chemistry, the Ziegler process is a method for producing fatty alcohols from ethylene using an organoaluminium compound. The reaction produces linear primary alcohols with an even numbered carbon chain. The process uses an aluminum compound to oligomerize ethylene and allow the resulting alkyl group to be oxygenated. The usually targeted products are fatty alcohols, which are otherwise derived from natural fats and oils. Fatty alcohols are used in food and chemical processing. They are useful due to their amphipathic nature. The synthesis route is named after Karl Ziegler, who described the process in 1955.

<span class="mw-page-title-main">Metallacyclopentanes</span>

In organometallic chemistry, metallacyclopentanes are compounds with the formula LnM(CH2)4 (Ln = ligands, and M = metal). They are a type of metallacycle. Metallacyclopentanes are intermediates in some metal-catalysed reactions in homogeneous catalysis.

References

  1. Lappin, George (Editor), Alpha Olefins Applications Handbook, Marcel Dekker Inc., ISBN   978-0-8247-7895-8
  2. (18 October 2010) Chevron Phillips Chemical announces plans for world-scale 1-hexene plant Archived 2014-11-29 at the Wayback Machine Plastinfo, Plastics Industry Directory, Retrieved 30 September 2011
  3. David S. McGuinness, Peter Wasserscheid, Wilhelm Keim, David Morgan, John T. Dixon, Annette Bollmann, Hulisani Maumela, Fiona Hess, and Ulli Englert "First Cr(III)−SNS Complexes and Their Use as Highly Efficient Catalysts for the Trimerization of Ethylene to 1-Hexene" J. Am. Chem. Soc., 2003, volume 125, pp 5272–5273. doi : 10.1021/ja034752f.
  4. "To make better decisions, you need to see the big picture".
  5. "1-Hexene". PubChem. National Institutes of Health. Retrieved 21 January 2019.