1-Octene is an

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon- hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. Th ...

with a formula CH₂CHC₆H₁₃. The

alkene In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, an ...

is classified as a higher

olefin In organic chemistry, an alkene is a hydrocarbon containing a carbon–carbon double bond. Alkene is often used as synonym of olefin, that is, any hydrocarbon containing one or more double bonds.H. Stephen Stoker (2015): General, Organic, an ...

and

alpha-olefin In organic chemistry, alpha-olefins (or α-olefins) are a family of organic compounds which are alkenes (also known as olefins) with a chemical formula , distinguished by having a double bond at the primary or alpha (α) position.''Petrochemical ...

, meaning that the

double bond In chemistry, a double bond is a covalent bond between two atoms involving four bonding electrons as opposed to two in a single bond. Double bonds occur most commonly between two carbon atoms, for example in alkenes. Many double bonds exist betw ...

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 olefin Linear alpha olefins (LAO) or normal alpha olefins (NAO) are olefins or alkenes with a chemical formula Cx H2x, distinguished from other mono-olefins with a similar molecular formula by linearity of the hydrocarbon chain and the position of the do ...

s in industry. It is a colourless liquid.

Synthesis

In industry, 1-octene is commonly manufactured by two main routes:

oligomerization In chemistry and biochemistry, an oligomer () is a molecule that consists of a few repeating units which could be derived, actually or conceptually, from smaller molecules, monomers.Quote: ''Oligomer molecule: A molecule of intermediate relati ...

ethylene Ethylene ( IUPAC name: ethene) is a hydrocarbon which has the formula or . It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene (a hydrocarbon with carbon-carbon double bonds). Ethylene ...

and by Fischer–Tropsch synthesis followed by purification. Another route to 1-octene that has been used commercially on a small scale is

dehydration In physiology, dehydration is a lack of total body water, with an accompanying disruption of metabolic processes. It occurs when free water loss exceeds free water intake, usually due to exercise, disease, or high environmental temperature. Mi ...

alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

s. Prior to the 1970s, 1-octene was also manufactured by thermal cracking of waxes, whereas linear internal

octene Octene is an alkene with the formula . Several isomers of octene are known, depending on the position and the geometry of the double bond in the carbon chain. The simplest isomer is 1-octene, an alpha-olefin used primarily as a co-monomer in p ...

s were also manufactured by chlorination/ dehydrochlorination of

linear alkane In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in ...

s. There are five commercial processes that oligomerize

to 1-octene. Four of these processes produce 1-octene as a part of a wide distribution of alpha-olefins. In typical circumstances, 1-hexene content of the entire distribution of alpha-olefins ranges from about 25% of the distribution in the Ethyl ( Innovene) process to about 8% of distribution in some modes of the

Gulf A gulf is a large inlet from the ocean into the landmass, typically with a narrower opening than a bay, but that is not observable in all geographic areas so named. The term gulf was traditionally used for large highly-indented navigable bodies ...

(CP Chemicals) and

Idemitsu is a Japanese petroleum company. It owns and operates oil platforms, refineries, produces and sells petroleum, oils and petrochemical products, and also operates gas stations under the brand and (until 2023) in its own ''Idemitsu'' and ''Shell ...

processes. The only commercial process to isolate 1-octene from a wide mixture of C₈ hydrocarbons is practiced by

Sasol Sasol Limited is an integrated energy and chemical company based in Sandton, South Africa. The company was formed in 1950 in Sasolburg, South Africa and built on processes that were first developed by German chemists and engineers in the early ...

, a

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring count ...

n oil and gas and petrochemical company. For commercial purposes, Sasol employs Fischer–Tropsch synthesis to make fuels from

synthesis gas Syngas, or synthesis gas, is a mixture of hydrogen and carbon monoxide, in various ratios. The gas often contains some carbon dioxide and methane. It is principly used for producing ammonia or methanol. Syngas is combustible and can be use ...

derived from coal and recovers 1-octene from these fuel streams, where the initial 1-octene concentration in a narrow

distillation Distillation, or classical distillation, is the process of separating the components or substances from a liquid mixture by using selective boiling and condensation, usually inside an apparatus known as a still. Dry distillation is the he ...

cut may be 60%, with the remainder being vinylidenes, linear and branched internal olefins, linear and branched paraffins,

aldehyde In organic chemistry, an aldehyde () is an organic compound containing a functional group with the structure . The functional group itself (without the "R" side chain) can be referred to as an aldehyde but can also be classified as a formyl group ...

carboxylic acid In organic chemistry, a carboxylic acid is an organic acid that contains a carboxyl group () attached to an R-group. The general formula of a carboxylic acid is or , with R referring to the alkyl, alkenyl, aryl, or other group. Carboxyl ...

s, and

aromatic hydrocarbon Aromatic compounds, also known as "mono- and polycyclic aromatic hydrocarbons", are organic compounds containing one or more aromatic rings. The parent member of aromatic compounds is benzene. The word "aromatic" originates from the past grou ...

s. In recent years, two on-purpose 1-octene technologies have been commercialised: a butadiene

telomerization Telomerization is a reaction that produces a particular kind of oligomer with two distinct end groups. The oligomer is called a telomer. Some telomerizations proceed by radical pathways, many do not. A generic equation is: : A-B + n M -> A-M_-B ...

plant (Dow, Tarragona), and a 1-heptene to 1-octene plant based on a Fischer-Tropsch-derived C₇ olefin stream (Sasol, Secunda). Sasol is currently in the engineering phase of a new 1-octene technology based on selective tetramerisation of ethylene.

Applications

The main use of 1-octene is as a

comonomer In polymer chemistry, a comonomer refers to a polymerizable precursor to a copolymer aside from the principal monomer. In some cases, only small amounts of a comonomer are employed, in other cases substantial amounts of comonomers are used. Furthe ...

in production of polyethylene.

High-density polyethylene High-density polyethylene (HDPE) or polyethylene high-density (PEHD) is a thermoplastic polymer produced from the monomer ethylene. It is sometimes called "alkathene" or "polythene" when used for HDPE pipes. With a high strength-to-density ratio, ...

(HDPE) and linear low-density polyethylene (LLDPE) use approximately 2–4% and 8–10% of comonomers, respectively. Another significant use of 1-octene is for production of linear

via oxo synthesis (

hydroformylation Hydroformylation, also known as oxo synthesis or oxo process, is an industrial process for the production of aldehydes from alkenes. This chemical reaction entails the net addition of a formyl group (CHO) and a hydrogen atom to a carbon-carbon d ...

) to give the C9 aldehyde ( nonanal). Oxidation of this aldehyde gives the short-chain

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...

nonanoic acid Pelargonic acid, also called nonanoic acid, is an organic compound with structural formula CH3(CH2)7CO2H. It is a nine-carbon fatty acid. Nonanoic acid is a colorless oily liquid with an unpleasant, rancid odor. It is nearly insoluble in water, ...

. Hydrogenation of the same aldehyde gives the

fatty alcohol Fatty alcohols (or long-chain alcohols) are usually high-molecular-weight, straight-chain primary alcohols, but can also range from as few as 4–6 carbons to as many as 22–26, derived from natural fats and oils. The precise chain length varie ...

1-nonanol 1-Nonanol is a straight chain fatty alcohol with nine carbon atoms and the molecular formula CH3(CH2)8OH. It is a colorless oily liquid with a citrus odor similar to citronella oil. Nonanol occurs naturally in orange oil. The primary use of non ...

, which is used as a

plasticizer A plasticizer ( UK: plasticiser) is a substance that is added to a material to make it softer and more flexible, to increase its plasticity, to decrease its viscosity, and/or to decrease friction during its handling in manufacture. Plasticiz ...

References

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