1-Octene
Encyclopedia
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.
and by Fischer-Tropsch synthesis followed by purification. Another route to 1-octene that has been used commercially on a small scale is dehydration
of alcohols. Prior to the 1970s, 1-octene was also manufactured by thermal cracking of waxes, whereas linear internal octenes were also manufactured by chlorination
/dehydrochlorination of linear paraffins.
There are five commercial processes that oligomerize ethylene
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
(CP Chemicals) and Idemitsu processes.
The only commercial process to isolate 1-octene from a wide mixture of C8 hydrocarbons is practiced by Sasol
, a South African oil and gas and petrochemical company. For commercial purposes, Sasol employs Fischer-Tropsch synthesis to make fuels from synthesis gas derived from coal and recovers 1-octene from these fuel streams, where the initial 1-octene concentration in a narrow distillation
cut may be 60%, with the remainder being vinylidenes, linear and branched internal olefins, linear and branched paraffins, alcohols, aldehydes, carboxylic acids, and aromatic compounds.
In recent years, two on-purpose 1-octene technologies have been commercialised: a butadiene telomerisation 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.
Another significant use of 1-octene is for production of linear aldehyde
via the oxo synthesis (hydroformylation
) to give the C9 aldehyde (nonanal). Oxidation of this aldehyde gives the short-chain fatty acid
nonanoic acid
. Hydrogenation of the same aldehyde gives the atty alcohol] 1-nonanol
, which is used as a plasticizer
.
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 a formula CH2CHC6H13. The alkene
Alkene
In organic chemistry, an alkene, olefin, or olefine is an unsaturated chemical compound containing at least one carbon-to-carbon double bond...
is classified as a higher olefin and alpha-olefin
Alpha-olefin
Alpha-olefins are a family of organic compounds which are olefins or alkenes with a chemical formula CxH2x, distinguished by having a double bond at the primary or alpha position...
, meaning that the double bond
Double bond
A double bond in chemistry is a chemical bond between two chemical elements involving four bonding electrons instead of the usual two. The most common double bond, that between two carbon atoms, can be found in alkenes. Many types of double bonds between two different elements exist, for example in...
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.
Synthesis
In industry, 1-octene is commonly manufactured by two main routes: oligomerization of ethyleneEthylene
Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...
and by Fischer-Tropsch synthesis followed by purification. Another route to 1-octene that has been used commercially on a small scale is dehydration
Dehydration reaction
In chemistry and the biological sciences, a dehydration reaction is usually defined as a chemical reaction that involves the loss of water from the reacting molecule. Dehydration reactions are a subset of elimination reactions...
of alcohols. Prior to the 1970s, 1-octene was also manufactured by thermal cracking of waxes, whereas linear internal octenes were also manufactured by chlorination
Chlorination
Chlorination is the process of adding the element chlorine to water as a method of water purification to make it fit for human consumption as drinking water...
/dehydrochlorination of linear paraffins.
There are five commercial processes that oligomerize ethylene
Ethylene
Ethylene is a gaseous organic compound with the formula . It is the simplest alkene . Because it contains a carbon-carbon double bond, ethylene is classified as an unsaturated hydrocarbon. Ethylene is widely used in industry and is also a plant hormone...
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
1-Hexene
1-Hexene is an organic compound with the formula CH2CHC4H9. 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 position, endowing the compound with higher reactivity and thus useful chemical...
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
Gulf Oil
Gulf Oil was a major global oil company from the 1900s to the 1980s. The eighth-largest American manufacturing company in 1941 and the ninth-largest in 1979, Gulf Oil was one of the so-called Seven Sisters oil companies...
(CP Chemicals) and Idemitsu processes.
The only commercial process to isolate 1-octene from a wide mixture of C8 hydrocarbons is practiced by Sasol
Sasol
Sasol Ltd. is a South African company involved in mining, energy, chemicals and synfuels. In particular, they produce petrol and diesel profitably from coal and natural gas using Fischer-Tropsch process...
, a South African oil and gas and petrochemical company. For commercial purposes, Sasol employs Fischer-Tropsch synthesis to make fuels from synthesis gas derived from coal and recovers 1-octene from these fuel streams, where the initial 1-octene concentration in a narrow distillation
Distillation
Distillation is a method of separating mixtures based on differences in volatilities of components in a boiling liquid mixture. Distillation is a unit operation, or a physical separation process, and not a chemical reaction....
cut may be 60%, with the remainder being vinylidenes, linear and branched internal olefins, linear and branched paraffins, alcohols, aldehydes, carboxylic acids, and aromatic compounds.
In recent years, two on-purpose 1-octene technologies have been commercialised: a butadiene telomerisation 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 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-octene is for production of linear aldehyde
Aldehyde
An aldehyde is an organic compound containing a formyl group. This functional group, with the structure R-CHO, consists of a carbonyl center bonded to hydrogen and an R group....
via the oxo synthesis (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...
) to give the C9 aldehyde (nonanal). Oxidation of this aldehyde gives the short-chain fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
nonanoic acid
Nonanoic acid
Nonanoic acid, also called pelargonic acid, is an organic compound composed of a nine-carbon chain terminating in a carboxylic acid with structural formula CH37COOH. Nonanoic acid forms esters—nonanoates. It is a clear, oily liquid with an unpleasant, rancid odor...
. Hydrogenation of the same aldehyde gives the atty alcohol] 1-nonanol
1-Nonanol
1-Nonanol is a straight chain fatty alcohol with nine carbon atoms and the molecular formula CH38OH. It is a colorless to slightly yellow liquid with a citrus odor similar to citronella oil....
, which is used as a plasticizer
Plasticizer
Plasticizers or dispersants are additives that increase the plasticity or fluidity of the material to which they are added; these include plastics, cement, concrete, wallboard, and clay. Although the same compounds are often used for both plastics and concretes the desired effects and results are...
.