Propylene
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Names | |||
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Preferred IUPAC name
Propene[1] | |||
Identifiers | |||
3D model (
JSmol ) |
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1696878 | |||
ChEBI | |||
ChEMBL | |||
ChemSpider | |||
ECHA InfoCard
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100.003.693 | ||
EC Number |
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852 | |||
KEGG | |||
PubChem CID
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RTECS number
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UNII | |||
UN number | 1075
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CompTox Dashboard (EPA)
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Properties | |||
C3H6 | |||
Molar mass | 42.081 g·mol−1 | ||
Appearance | Colorless gas | ||
Density | 1.81 kg/m3, gas (1.013 bar, 15 °C) 1.745 kg/m3, gas (1.013 bar, 25 °C) 613.9 kg/m3, liquid | ||
Melting point | −185.2 °C (−301.4 °F; 88.0 K) | ||
Boiling point | −47.6 °C (−53.7 °F; 225.6 K) | ||
0.61 g/m3 | |||
-31.5·10−6 cm3/mol | |||
Viscosity | 8.34 µPa·s at 16.7 °C
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Structure | |||
0.366 D (gas) | |||
Hazards | |||
GHS labelling:[2] | |||
Danger | |||
H220 | |||
P210, P377, P381, P403 | |||
NFPA 704 (fire diamond) | |||
Flash point | −108 °C (−162 °F; 165 K) | ||
Safety data sheet (SDS) | External MSDS | ||
Related compounds | |||
Related alkenes;
related groups |
Allyl, Propenyl
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Related compounds
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Propane, Propyne Propadiene, 1-Propanol 2-Propanol | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Propylene, also known as propene, is an
Propylene is a product of combustion from forest fires, cigarette smoke, and motor vehicle and aircraft exhaust.[4] It was discovered in 1850 by A. W. von Hoffman's student Captain (later Major General[5]) John Williams Reynolds as the only gaseous product of thermal decomposition of amyl alcohol to react with chlorine and bromine.[6]
Production
Steam cracking
The dominant technology for producing propylene is
Olefin conversion technology
In the Phillips triolefin or
The technology is founded on an olefin metathesis reaction discovered at Phillips Petroleum Company.[10][11] Propylene yields of about 90 wt% are achieved.
Related is the
Fluid catalytic cracking
High severity fluid catalytic cracking (FCC) uses traditional FCC technology under severe conditions (higher catalyst-to-oil ratios, higher steam injection rates, higher temperatures, etc.) in order to maximize the amount of propene and other light products. A high severity FCC unit is usually fed with gas oils (paraffins) and residues, and produces about 20–25% (by mass) of propene on feedstock together with greater volumes of motor gasoline and distillate byproducts. These high temperature processes are expensive and have a high carbon footprint. For these reasons, alternative routes to propylene continue to attract attention.[12]
Other commercialized methods
On-purpose propylene production technologies were developed throughout the twentieth century. Of these, propane dehydrogenation technologies such as the CATOFIN and OLEFLEX processes have become common, although they still make up a minority of the market, with most of the olefin being sourced from the above mentioned cracking technologies. Platinum, chromia, and vanadium catalysts are common in propane dehydrogenation processes.
Market
Propene production has remained static at around 35 million
Research
The use of engineered enzymes has been explored but has not been commercialized.[14]
There is ongoing research into the use of oxygen carrier catalysts for the oxidative dehydrogenation of propane. This poses several advantages, as this reaction mechanism can occur at lower temperatures than conventional dehydrogenation, and may not be equilibrium-limited because oxygen is used to combust the hydrogen by-product.[15]
Uses
Propene is the second most important starting product in the petrochemical industry after ethylene. It is the raw material for a wide variety of products. Polypropylene manufacturers consume nearly two thirds of global production.[16] Polypropylene end uses include films, fibers, containers, packaging, and caps and closures. Propene is also used for the production of important chemicals such as propylene oxide, acrylonitrile, cumene, butyraldehyde, and acrylic acid. In the year 2013 about 85 million tonnes of propene were processed worldwide.[16]
Propene and benzene are converted to acetone and phenol via the cumene process.
Propene is also used to produce isopropyl alcohol (propan-2-ol), acrylonitrile, propylene oxide, and epichlorohydrin.[17] The industrial production of acrylic acid involves the catalytic partial oxidation of propene.[18] Propylene is an intermediate in the oxidation to acrylic acid.
In industry and workshops, propene is used as an alternative fuel to acetylene in Oxy-fuel welding and cutting, brazing and heating of metal for the purpose of bending. It has become a standard in BernzOmatic products and others in MAPP substitutes,[19] now that true MAPP gas is no longer available.
Reactions
Propene resembles other alkenes in that it undergoes
Complexes of transition metals
Foundational to hydroformylation, alkene metathesis, and polymerization are
Polymerization
The majority of propene is used to form polypropylene, a very important commodity thermoplastic, through chain-growth polymerization.[16] In the presence of a suitable catalyst (typically a Ziegler–Natta catalyst), propene will polymerize. There are multiple ways to achieve this, such as using high pressures to suspending the catalyst in a solution of liquid propene, or running gaseous propene through a fluidized bed reactor.[20]
Dimerization
In the presence of
Environmental safety
Propene is a product of combustion from forest fires, cigarette smoke, and motor vehicle and aircraft exhaust.
In the United States and some European countries a
Propene has low acute toxicity from inhalation and is not considered to be carcinogenic. Chronic toxicity studies in mice did not yield significant evidence suggesting adverse effects. Humans briefly exposed to 4,000 ppm did not experience any noticeable effects.[22] Propene is dangerous from its potential to displace oxygen as an asphyxiant gas, and from its high flammability/explosion risk.
Bio-propylene is the
It has been examined, motivated by diverse interests such a carbon footprint. Production from glucose has been considered.[25] More advanced ways of addressing such issues focus on electrification alternatives to steam cracking.Storage and handling
Propene is flammable. Propene is usually stored as liquid under pressure, although it is also possible to store it safely as gas at ambient temperature in approved containers.[26]
Occurrence in nature
Propene is detected in the
See also
- Los Alfaques Disaster
- Inhalant abuse
- 2014 Kaohsiung gas explosions
- 2020 Houston explosion
References
- ISBN 978-0-85404-182-4.
- ^ "Propylene". pubchem.ncbi.nlm.nih.gov. Retrieved 14 December 2021.
- ^ "Propylene".
- ^ PMID 29300328.
- ^ "Maj Gen John Williams Reynolds, FCS". geni_family_tree. 1816-12-25. Retrieved 2023-12-30.
- ISBN 978-3-319-95489-9, retrieved 2023-12-30
- ISBN 978-0-9522674-3-0, pages 7766-9
- ^ a b c "Product Safety Assessment(PSA): Propylene". Dow Chemical Co. Archived from the original on 2013-08-28. Retrieved 2011-07-11.
- S2CID 103664623.
- .
- ISBN 978-0-471-23896-6.
- S2CID 117360588.
- .
- ^ de Guzman, Doris (October 12, 2012). "Global Bioenergies in bio-propylene". Green Chemicals Blog.
- ISSN 0255-2701.
- ^ a b c "Market Study: Propylene (2nd edition), Ceresana, December 2014". ceresana.com. Retrieved 2015-02-03.
- ^ Budavari, Susan, ed. (1996). "8034. Propylene". The Merck Index, Twelfth Edition. New Jersey: Merck & Co. pp. 1348–1349.
- ^ J.G.L., Fierro (Ed.) (2006). Metal Oxides, Chemistry and Applications. CRC Press. pp. 414–455.
- ^ For example, "MAPP-Pro"
- ISBN 978-3-527-30673-2, retrieved 2021-07-09
- S2CID 221124789.
- ^ PubChem. "Hazardous Substances Data Bank (HSDB): 175". pubchem.ncbi.nlm.nih.gov. Retrieved 2021-07-09.
- ^ Bio-based drop-in, smart drop-in and dedicated chemicals
- ^ Duurzame bioplastics op basis van hernieuwbare grondstoffen
- ^ Guzman, Doris de (12 October 2012). "Global Bioenergies in bio-propylene". Green Chemicals Blog. Retrieved 2021-07-09.
- ISBN 0471-52689-4(v.20), page 261
- S2CID 15832967.
- ^ "Spacecraft finds propylene on Saturn moon, Titan". UPI.com. 2013-09-30. Retrieved 2013-11-12.
- ^ "Cassini finds ingredient of household plastic on Saturn moon". Spacedaily.com. Retrieved 2013-11-12.