1-Hexene

Chembox new
Name = 1-Hexene
ImageFile = 1-Hexene.png ImageName = 1-Hexene
IUPACName = Hex-1-ene
OtherNames = Hexene, Hexylene, butyl ethylene
Section1 = Chembox Identifiers
SMILES = C=CCCCC
CASNo = 592-41-6
Section2 = Chembox Properties
Formula = C₆H_{12
MolarMass = 84.1608 g/mol
Appearance = Colorless liquid
Density = .673 g/cm³, liquid
Solubility = insoluble
MeltingPt = -139.8°C (133.35 K)
BoilingPt = 63°C (336 K)
Viscosity = .51 cP at 28°C}
Section3 = Chembox Structure
Dipole =
Section7 = Chembox Hazards
ExternalMSDS = [http://ptcl.chem.ox.ac.uk/MSDS/HE/1-hexene.html External MSDS]
EUClass = Highly flammable (F+); Harmful (XN)

1-hexene is a higher olefin, or alkene, with a formula C₆H₁₂. 1-hexene is an alpha-olefin, 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.

ynthesis

Industrially, 1-hexene is commonly manufactured by two main routes: via full range processes using the oligomerization of ethene and by on-purpose technology. Another route to 1-hexene, used commercially on smaller scales, is the dehydration of alcohols. Prior to the 1970's 1-hexene was also manufactured by the thermal cracking of waxes. Linear internal hexenes were manufactured by chlorination/dehydrochlorination of linear paraffins.

Ethene molecules that are combined together to produce linear alpha olefins of various chain lengths with an even number of carbon atoms use ethene oligomerization and result in a distribution or “full range” of alpha olefins. Shell uses the Shell Higher Olefins Process (SHOP-process) to produce a broad range of linear alpha olefins using olefin metathesis and ethene oligomerization. Linde and SABIC (Saudi Arabian Basic Industries) have developed the α-SABLIN technology using the oligomerization of ethene 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.

The on-purpose route to 1-hexene using ethene trimerization was first brought on stream in Qatar in 2003 by Chevron Phillips. 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 afformentioned 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.Lummus Technology has recently developed a new on purpose route where 1-butene reacts with itself (“autometathesis” or “self-disproportionation”) to produce 1-hexene. A semi commercial unit has been in operation in Tianjin, China to demonstrate the Lummus technology.

Applications

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

Another significant use of 1-hexene is the production of linear aldehyde via hydroformylation ( oxo synthesis ) for later production of the short-chain fatty acid heptanoic acid.

References

External links

* [http://ull.chemistry.uakron.edu/erd/chemicals/1000/71.html Chemical Database, 1-Hexene]