Pentene

Last updated
n-Pentene
1-pentene.svg
1-Pentene
Cis-2-pentene.svg
cis-2-Pentene
Trans-2-pentene.svg
trans-2-Pentene
Names
IUPAC names
Pent-1-ene
cis-Pent-2-ene
trans-Pent-2-ene
Other names
amylene, n-amylene, n-pentene, beta-n-amylene, sym-methylethylethylene, pentylene
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.042.636 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 246-916-6 (1-pentene)
    273-308-8 (cis-2-pentene)
    271-255-5 (trans-2-pentene)
PubChem CID
UNII
  • (1-pentene):InChI=1S/C5H10/c1-3-5-4-2/h3H,1,4-5H2,2H3
    Key: YWAKXRMUMFPDSH-UHFFFAOYSA-N
  • (cis-2-pentene):InChI=1S/C5H10/c1-3-5-4-2/h3,5H,4H2,1-2H3/b5-3-
    Key: QMMOXUPEWRXHJS-HYXAFXHYSA-N
  • (trans-2-pentene):InChI=1S/C5H10/c1-3-5-4-2/h3,5H,4H2,1-2H3/b5-3+
    Key: QMMOXUPEWRXHJS-HWKANZROSA-N
  • (1-pentene):CCCC=C
  • (cis-2-pentene):CC/C=C\C
  • (trans-2-pentene):CC/C=C/C
Properties
C5H10
Molar mass 70.135 g·mol−1
Density 0.64 g/cm3 (1-pentene) [1]
Melting point −165.2 °C (−265.4 °F; 108.0 K) (1-pentene) [1]
Boiling point 30 °C (86 °F; 303 K) (1-pentene) [1]
-53.7·10−6 cm3/mol
Hazards
Safety data sheet (SDS) MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Pentenes (also called Pentylenes) are alkenes with the chemical formula C
5
H
10
. Each molecule contains one double bond within its molecular structure. Six different compounds are in this class, differing from each other by whether the carbon atoms are attached linearly or in a branched structure and whether the double bond has a cis or trans form.

Contents

Straight-chain isomers

1-Pentene is an alpha-olefin. Most often, 1-pentene is made as a byproduct of catalytic or thermal cracking of petroleum or during the production of ethylene and propylene via thermal cracking of hydrocarbon fractions.

The only commercial manufacturer of 1-pentene is Sasol Ltd., where it is separated from crude by the Fischer-Tropsch process. [2]

2-Pentene has two geometric isomers: cis-2-pentene and trans-2-pentene. Cis-2-Pentene is used in olefin metathesis.

Branched-chain isomers

The branched isomers are 2-methylbut-1-ene, 3-methylbut-1-ene (isopentene), and 2-methylbut-2-ene (isoamylene).

Isoamylene is one of the three main byproducts of deep catalytic cracking (DCC), which is very similar to the operation of fluid catalytic cracking (FCC). The DCC uses vacuum gas oil (VGO) as a feedstock to produce primarily propylene, isobutylene, and isoamylene. The rise in demand for polypropylene has encouraged the growth of the DCC, which is operated very much like the FCC. Isobutylene and isoamylene feedstocks are necessary for the production of the much debated gasoline blending components methyl tert-butyl ether and tert-amyl methyl ether.

Production of fuels

Propylene, isobutene, and amylenes are feedstocks in the alkylation units of refineries. Using isobutane, blendstocks are generated with high branching for good combustion characteristics. Amylenes are valued as precursors to fuels, especially aviation fuels of relatively low volatility, as required by various regulations. [3]

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. The double bond may be internal or in the terminal position. Terminal alkenes are also known as α-olefins.

<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.

Isobutane, also known as i-butane, 2-methylpropane or methylpropane, is a chemical compound with molecular formula HC(CH3)3. It is an isomer of butane. Isobutane is a colorless, odorless gas. It is the simplest alkane with a tertiary carbon atom. Isobutane is used as a precursor molecule in the petrochemical industry, for example in the synthesis of isooctane.

In chemistry, isomerization or isomerisation is the process in which a molecule, polyatomic ion or molecular fragment is transformed into an isomer with a different chemical structure. Enolization is an example of isomerization, as is tautomerization. When the isomerization occurs intramolecularly it may be called a rearrangement reaction.

<span class="mw-page-title-main">Cracking (chemistry)</span> Process whereby complex organic molecules are broken down into simpler molecules

In petrochemistry, petroleum geology and organic chemistry, cracking is the process whereby complex organic molecules such as kerogens or long-chain hydrocarbons are broken down into simpler molecules such as light hydrocarbons, by the breaking of carbon-carbon bonds in the precursors. The rate of cracking and the end products are strongly dependent on the temperature and presence of catalysts. Cracking is the breakdown of a large hydrocarbons into smaller, more useful alkanes and alkenes. Simply put, hydrocarbon cracking is the process of breaking a long chain of hydrocarbons into short ones. This process requires high temperatures.

<span class="mw-page-title-main">Alkylation</span> Transfer of an alkyl group from one molecule to another

Alkylation is a chemical reaction that entails transfer of an alkyl group. The alkyl group may be transferred as an alkyl carbocation, a free radical, a carbanion, or a carbene. Alkylating agents are reagents for effecting alkylation. Alkyl groups can also be removed in a process known as dealkylation. Alkylating agents are often classified according to their nucleophilic or electrophilic character. In oil refining contexts, alkylation refers to a particular alkylation of isobutane with olefins. For upgrading of petroleum, alkylation produces a premium blending stock for gasoline. In medicine, alkylation of DNA is used in chemotherapy to damage the DNA of cancer cells. Alkylation is accomplished with the class of drugs called alkylating antineoplastic agents.

Propylene, also known as propene, is an unsaturated organic compound with the chemical formula CH3CH=CH2. It has one double bond, and is the second simplest member of the alkene class of hydrocarbons. It is a colorless gas with a faint petroleum-like odor.

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.

<span class="mw-page-title-main">Isobutylene</span> Unsaturated hydrocarbon compound (H2C=C(CH3)2)

Isobutylene is a hydrocarbon with the chemical formula (CH3)2C=CH2. It is a four-carbon branched alkene (olefin), one of the four isomers of butylene. It is a colorless flammable gas, and is of considerable industrial value.

<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.

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, alpha (α), or 1- 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">Synthetic molecular motor</span>

Synthetic molecular motors are molecular machines capable of continuous directional rotation under an energy input. Although the term "molecular motor" has traditionally referred to a naturally occurring protein that induces motion, some groups also use the term when referring to non-biological, non-peptide synthetic motors. Many chemists are pursuing the synthesis of such molecular motors.

<span class="mw-page-title-main">Fluid catalytic cracking</span> Petroleum conversion process

Fluid Catalytic Cracking (FCC) is the conversion process used in petroleum refineries to convert the high-boiling point, high-molecular weight hydrocarbon fractions of petroleum into gasoline, alkene gases, and other petroleum products. The cracking of petroleum hydrocarbons was originally done by thermal cracking, now virtually replaced by catalytic cracking, which yields greater volumes of high octane rating gasoline; and produces by-product gases, with more carbon-carbon double bonds, that are of greater economic value than the gases produced by thermal cracking.

<span class="mw-page-title-main">Prins reaction</span> Chemical reaction involving organic compounds

The Prins reaction is an organic reaction consisting of an electrophilic addition of an aldehyde or ketone to an alkene or alkyne followed by capture of a nucleophile or elimination of an H+ ion. The outcome of the reaction depends on reaction conditions. With water and a protic acid such as sulfuric acid as the reaction medium and formaldehyde the reaction product is a 1,3-diol (3). When water is absent, the cationic intermediate loses a proton to give an allylic alcohol (4). With an excess of formaldehyde and a low reaction temperature the reaction product is a dioxane (5). When water is replaced by acetic acid the corresponding esters are formed.

In chemistry, a Grob fragmentation is an elimination reaction that breaks a neutral aliphatic chain into three fragments: a positive ion spanning atoms 1 and 2, an unsaturated neutral fragment spanning positions 3 and 4, and a negative ion comprising the rest of the chain.

C<sub>5</sub>H<sub>10</sub> Index of chemical compounds with the same molecular formula

C5H10 is the molecular formula' of 13 hydrocarbon isomers (represented by their CAS numbers on the chart). They can be divided into cycloalkanes and alkenes.

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">Fawley Refinery</span> Oil refinery in Hampshire, England

Fawley Refinery is an oil refinery located at Fawley, Hampshire, England. The refinery is owned by Esso Petroleum Company Limited, a subsidiary of Exxon Mobil Corporation, which acquired the site in 1925. Situated on Southampton Water, it was rebuilt and extended in 1951 and is now the largest oil refinery in the United Kingdom, and one of the most complex refineries in Europe. With a capacity of 270,000 barrels (43,000 m3) per day, Fawley provides 20 per cent of the UK's refinery capacity. Over 2,500 people are employed at the site.

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

An alkylation unit (alky) is one of the conversion processes used in petroleum refineries. It is used to convert isobutane and low-molecular-weight alkenes (primarily a mixture of propene and butene) into alkylate, a high octane gasoline component. The process occurs in the presence of an acid such as sulfuric acid (H2SO4) or hydrofluoric acid (HF) as catalyst. Depending on the acid used, the unit is called a sulfuric acid alkylation unit (SAAU) or hydrofluoric acid alkylation unit (HFAU). In short, the alky produces a high-quality gasoline blending stock by combining two shorter hydrocarbon molecules into one longer chain gasoline-range molecule by mixing isobutane with a light olefin such as propylene or butylene from the refinery's fluid catalytic cracking unit (FCCU) in the presence of an acid catalyst.

References

  1. 1 2 3 Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  2. "RSA Olefins | cChange". www.cchange.ac.za. Retrieved 2017-10-19.
  3. Bipin V. Vora; Joseph A. Kocal; Paul T. Barger; Robert J. Schmidt; James A. Johnson (2003). "Alkylation". Kirk‐Othmer Encyclopedia of Chemical Technology. doi:10.1002/0471238961.0112112508011313.a01.pub2. ISBN   0-471-23896-1.