Propylene

Last updated
Propylene
Skeletal formula of propene Propylene skeletal.svg
Skeletal formula of propene
Propene-2D-flat.svg
Propylene-GED-MW-3D-sf.png
Propylene Propylene-GED-MW-3D-bs-17.png
Propylene
Names
Preferred IUPAC name
Propene [1] [2]
Identifiers
3D model (JSmol)
1696878
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.003.693 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 204-062-1
852
KEGG
PubChem CID
RTECS number
  • UC6740000
UNII
UN number 1077
In Liquefied petroleum gas: 1075
  • InChI=1S/C3H6/c1-3-2/h3H,1H2,2H3 Yes check.svgY
    Key: QQONPFPTGQHPMA-UHFFFAOYSA-N Yes check.svgY
  • InChI=1/C3H6/c1-3-2/h3H,1H2,2H3
    Key: QQONPFPTGQHPMA-UHFFFAOYAA
  • C=CC
  • CC=C
Properties
C3H6
Molar mass 42.081 g·mol−1
AppearanceColorless 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
Structure
0.366 D (gas)
Hazards
GHS labelling: [3]
GHS-pictogram-flamme.svg
Danger
H220
P210, P377, P381, P403
NFPA 704 (fire diamond)
NFPA 704.svgHealth 1: Exposure would cause irritation but only minor residual injury. E.g. turpentineFlammability 4: Will rapidly or completely vaporize at normal atmospheric pressure and temperature, or is readily dispersed in air and will burn readily. Flash point below 23 °C (73 °F). E.g. propaneInstability 1: Normally stable, but can become unstable at elevated temperatures and pressures. E.g. calciumSpecial hazards (white): no code
1
4
1
Flash point −108 °C (−162 °F; 165 K)
Safety data sheet (SDS) External MSDS
Related compounds
Related alkenes;
related groups
 Ethylene, Isomers of Butylene;
Allyl, Propenyl
Related compounds
 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).
Yes check.svgY  verify  (what is  Yes check.svgYX mark.svgN ?)

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. [4]

Contents

Propylene is a product of combustion from forest fires, cigarette smoke, and motor vehicle and aircraft exhaust. [5] It was discovered in 1850 by A. W. von Hoffman's student Captain (later Major General [6] ) John Williams Reynolds as the only gaseous product of thermal decomposition of amyl alcohol to react with chlorine and bromine. [7]

Production

Steam cracking

The dominant technology for producing propylene is steam cracking, using propane as the feedstock. Cracking propane yields a mixture of ethylene, propylene, methane, hydrogen gas, and other related compounds. The yield of propylene is about 15%. The other principal feedstock is naphtha, especially in the Middle East and Asia. [8] Propylene can be separated by fractional distillation from the hydrocarbon mixtures obtained from cracking and other refining processes; refinery-grade propene is about 50 to 70%. [9] In the United States, shale gas is a major source of propane.

Olefin conversion technology

In the Phillips triolefin or olefin conversion technology, propylene is interconverted with ethylene and 2-butenes. Rhenium and molybdenum catalysts are used: [10]

The technology is founded on an olefin metathesis reaction discovered at Phillips Petroleum Company. [11] [12] Propylene yields of about 90 wt% are achieved.

Related is the Methanol-to-Olefins/Methanol-to-Propene process. It converts synthesis gas (syngas) to methanol, and then converts the methanol to ethylene and/or propene. The process produces water as a by-product. Synthesis gas is produced from the reformation of natural gas or by the steam-induced reformation of petroleum products such as naphtha, or by gasification of coal or natural gas.

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. [13]

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 tonnes (Europe and North America only) from 2000 to 2008, but it has been increasing in East Asia, most notably Singapore and China. [14] Total world production of propene is currently about half that of ethylene.

Research

The use of engineered enzymes has been explored but has not been commercialized. [15]

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. [16]

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. [17] 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. [17]

Propene and benzene are converted to acetone and phenol via the cumene process.

Overview of the cumene process Cumene-process-overview-2D-skeletal.png
Overview of the cumene process

Propene is also used to produce isopropyl alcohol (propan-2-ol), acrylonitrile, propylene oxide, and epichlorohydrin. [18] The industrial production of acrylic acid involves the catalytic partial oxidation of propene. [19] 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, [20] now that true MAPP gas is no longer available.

Reactions

Propene resembles other alkenes in that it undergoes addition reactions relatively easily at room temperature. The relative weakness of its double bond explains its tendency to react with substances that can achieve this transformation. Alkene reactions include: 1) polymerization, 2) oxidation, 3) halogenation and hydrohalogenation, 4) alkylation, 5) hydration, 6) oligomerization, and 7) hydroformylation.

Complexes of transition metals

Foundational to hydroformylation, alkene metathesis, and polymerization are metal-propylene complexes, which are intermediates in these processes. Propylene is prochiral, meaning that binding of a reagent (such as a metal electrophile) to the C=C group yields one of two enantiomers.

Polymerization

The majority of propene is used to form polypropylene, a very important commodity thermoplastic, through chain-growth polymerization. [17] 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. [21]

Polypropylene.png

Dimerization

In the presence of catalysts, propylene dimerizes to give 2,3-dimethyl-1-butene and/or 2,3-dimethyl-2-butene. [22]

Environmental safety

Propene is a product of combustion from forest fires, cigarette smoke, and motor vehicle and aircraft exhaust. [5] It is an impurity in some heating gases. Observed concentrations have been in the range of 0.1–4.8 parts per billion (ppb) in rural air, 4–10.5 ppb in urban air, and 7–260 ppb in industrial air samples. [9]

In the United States and some European countries a threshold limit value of 500 parts per million (ppm) was established for occupational (8-hour time-weighted average) exposure. It is considered a volatile organic compound (VOC) and emissions are regulated by many governments, but it is not listed by the U.S. Environmental Protection Agency (EPA) as a hazardous air pollutant under the Clean Air Act. With a relatively short half-life, it is not expected to bioaccumulate. [9]

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. [23] Propene is dangerous from its potential to displace oxygen as an asphyxiant gas, and from its high flammability/explosion risk.

Bio-propylene is the bio-based propylene. [24] [25] It has been examined, motivated by diverse interests such a carbon footprint. Production from glucose has been considered. [26] 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. [27]

Occurrence in nature

Propene is detected in the interstellar medium through microwave spectroscopy. [28] On September 30, 2013, NASA also announced that the Cassini orbiter spacecraft, part of the Cassini-Huygens mission, had discovered small amounts of naturally occurring propene in the atmosphere of Titan using spectroscopy. [29] [30]

See also

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, or olefin, 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">Ethylene</span> Hydrocarbon compound (H₂C=CH₂)

Ethylene is a hydrocarbon which has the formula C2H4 or H2C=CH2. It is a colourless, flammable gas with a faint "sweet and musky" odour when pure. It is the simplest alkene.

A Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, is a catalyst used in the synthesis of polymers of 1-alkenes (alpha-olefins). Two broad classes of Ziegler–Natta catalysts are employed, distinguished by their solubility:

<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.

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 large hydrocarbons into smaller, more useful alkanes and alkenes. Simply put, hydrocarbon cracking is the process of breaking long-chain 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.

In chemistry, dehydrogenation is a chemical reaction that involves the removal of hydrogen, usually from an organic molecule. It is the reverse of hydrogenation. Dehydrogenation is important, both as a useful reaction and a serious problem. At its simplest, it's a useful way of converting alkanes, which are relatively inert and thus low-valued, to olefins, which are reactive and thus more valuable. Alkenes are precursors to aldehydes, alcohols, polymers, and aromatics. As a problematic reaction, the fouling and inactivation of many catalysts arises via coking, which is the dehydrogenative polymerization of organic substrates.

In organic chemistry, 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 and a hydrogen atom to a carbon-carbon double bond. This process has undergone continuous growth since its invention: production capacity reached 6.6×106 tons in 1995. It is important because aldehydes are easily converted into many secondary products. For example, the resultant aldehydes are hydrogenated to alcohols that are converted to detergents. Hydroformylation is also used in speciality chemicals, relevant to the organic synthesis of fragrances and pharmaceuticals. The development of hydroformylation is one of the premier achievements of 20th-century industrial chemistry.

In chemistry, homogeneous catalysis is catalysis where the catalyst is in same phase as reactants, principally by a soluble catalyst in a solution. In contrast, heterogeneous catalysis describes processes where the catalysts and substrate are in distinct phases, typically solid and gas, respectively. The term is used almost exclusively to describe solutions and implies catalysis by organometallic compounds. Homogeneous catalysis is an established technology that continues to evolve. An illustrative major application is the production of acetic acid. Enzymes are examples of homogeneous catalysts.

<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.

<span class="mw-page-title-main">Olefin metathesis</span> Organic reaction involving the breakup and reassembly of alkene double bonds

In organic chemistry, olefin metathesis is an organic reaction that entails the redistribution of fragments of alkenes (olefins) by the scission and regeneration of carbon-carbon double bonds. Because of the relative simplicity of olefin metathesis, it often creates fewer undesired by-products and hazardous wastes than alternative organic reactions. For their elucidation of the reaction mechanism and their discovery of a variety of highly active catalysts, Yves Chauvin, Robert H. Grubbs, and Richard R. Schrock were collectively awarded the 2005 Nobel Prize in Chemistry.

Coordination polymerisation is a form of polymerization that is catalyzed by transition metal salts and complexes.

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">Terminal alkene</span> Hydrocarbon compounds with a C=C bond at the alpha carbon

In organic chemistry, terminal alkenes 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">1-Butene</span> Chemical compound

1-Butene (IUPAC name: But-1-ene, also known as 1-butylene) is the organic compound with the formula CH3CH2CH=CH2. It is a colorless gas. But-1-ene is an alkene easily condensed to give a colorless liquid. It is classified as a linear alpha-olefin (terminal alkene). It is one of the isomers of butene (butylene). It is a precursor to diverse products.

<span class="mw-page-title-main">Concurrent tandem catalysis</span>

Concurrent tandem catalysis (CTC) is a technique in chemistry where multiple catalysts produce a product otherwise not accessible by a single catalyst. It is usually practiced as homogeneous catalysis. Scheme 1 illustrates this process. Molecule A enters this catalytic system to produce the comonomer, B, which along with A enters the next catalytic process to produce the final product, P. This one-pot approach can decrease product loss from isolation or purification of intermediates. Reactions with relatively unstable products can be generated as intermediates because they are only transient species and are immediately used in a consecutive reaction.

In organic chemistry, ethenolysis is a chemical process in which internal olefins are degraded using ethylene as the reagent. The reaction is an example of cross metathesis. The utility of the reaction is driven by the low cost of ethylene as a reagent and its selectivity. It produces compounds with terminal alkene functional groups (α-olefins), which are more amenable to other reactions such as polymerization and hydroformylation.

<span class="mw-page-title-main">Herbert S. Eleuterio</span> American industrial chemist (1927–2022)

Herbert S. Eleuterio was an American industrial chemist noted for technical contributions to catalysis, polymerization, industrial research management, and science education. In particular, he discovered the olefin metathesis reaction and several novel fluoropolymers. Additionally, he explored techniques for research leadership, especially methods for fostering collaboration, globalization, and scientific creativity.

Olefin Conversion Technology, also called the Phillips Triolefin Process, is the industrial process that interconverts propylene with ethylene and 2-butenes. The process is also called the ethylene to propylene (ETP) process. In ETP, ethylene is dimerized to 1-butene, which is isomerized to 2-butenes. The 2-butenes are then subjected to metathesis with ethylene.

<span class="mw-page-title-main">Steam cracking</span> Petrochemical process to break down saturated hydrocarbons in smaller molecules

Steam cracking is a petrochemical process in which saturated hydrocarbons are broken down into smaller, often unsaturated, hydrocarbons. It is the principal industrial method for producing the lighter alkenes, including ethene and propene. Steam cracker units are facilities in which a feedstock such as naphtha, liquefied petroleum gas (LPG), ethane, propane or butane is thermally cracked through the use of steam in steam cracking furnaces to produce lighter hydrocarbons. The propane dehydrogenation process may be accomplished through different commercial technologies. The main differences between each of them concerns the catalyst employed, design of the reactor and strategies to achieve higher conversion rates.

References

  1. ↑ "General Principles, Rules, and Conventions". Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 31. doi:10.1039/9781849733069-00001. ISBN   978-0-85404-182-4.
  2. ↑ Moss, G.P. (web version). "P-14.3 Locants". Nomenclature of Organic Chemistry. IUPAC Recommendations and Preferred Names 2013. London: Queen Mary University. Section P-14.3.4.2 (d). Retrieved 23 August 2024.
  3. ↑ "Propylene". pubchem.ncbi.nlm.nih.gov. Retrieved 14 December 2021.
  4. ↑ "Propylene".
  5. 1 2 Morgott, David (2018-01-04). "The Human Exposure Potential from Propylene Releases to the Environment". International Journal of Environmental Research and Public Health. 15 (1): 66. doi: 10.3390/ijerph15010066 . ISSN   1660-4601. PMC   5800165 . PMID   29300328.
  6. ↑ "Maj Gen John Williams Reynolds, FCS". geni_family_tree. 1816-12-25. Retrieved 2023-12-30.
  7. ↑ Rasmussen, Seth C. (2018), Rasmussen, Seth C. (ed.), "Introduction", Acetylene and Its Polymers: 150+ Years of History, SpringerBriefs in Molecular Science, Cham: Springer International Publishing, pp. 1–19, doi:10.1007/978-3-319-95489-9_1, ISBN   978-3-319-95489-9 , retrieved 2023-12-30
  8. ↑ Ashford's Dictionary of Industrial Chemicals, Third edition, 2011, ISBN   978-0-9522674-3-0, pages 7766-9
  9. 1 2 3 "Product Safety Assessment(PSA): Propylene". Dow Chemical Co. Archived from the original on 2013-08-28. Retrieved 2011-07-11.
  10. ↑ Ghashghaee, Mohammad (2018). "Heterogeneous catalysts for gas-phase conversion of ethylene to higher olefins". Rev. Chem. Eng. 34 (5): 595–655. doi:10.1515/revce-2017-0003. S2CID   103664623.
  11. ↑ Banks, R. L.; Bailey, G. C. (1964). "Olefin Disproportionation. A New Catalytic Process". Industrial & Engineering Chemistry Product Research and Development. 3 (3): 170–173. doi:10.1021/i360011a002.
  12. ↑ Lionel Delaude; Alfred F. Noels (2005). "Metathesis". Kirk-Othmer Encyclopedia of Chemical Technology. Weinheim: Wiley-VCH. doi:10.1002/0471238961.metanoel.a01. ISBN   978-0-471-23896-6.
  13. ↑ Schiffer, Zachary J.; Manthiram, Karthish (2017). "Electrification and Decarbonization of the Chemical Industry". Joule. 1 (1): 10–14. Bibcode:2017Joule...1...10S. doi:10.1016/j.joule.2017.07.008. hdl: 1721.1/124019 . S2CID   117360588.
  14. ↑ Amghizar, Ismaël; Vandewalle, Laurien A.; Van Geem, Kevin M.; Marin, Guy B. (2017). "New Trends in Olefin Production". Engineering. 3 (2): 171–178. Bibcode:2017Engin...3..171A. doi: 10.1016/J.ENG.2017.02.006 .
  15. ↑ de Guzman, Doris (October 12, 2012). "Global Bioenergies in bio-propylene". Green Chemicals Blog.
  16. ↑ Wu, Tianwei; Yu, Qingbo; Roghair; et al. (2020). "Chemical looping oxidative dehydrogenation of propane: A comparative study of Ga-based, Mo-based, V-based oxygen carriers". Chemical Engineering and Processing - Process Intensification. 157: 108137. Bibcode:2020CEPPI.15708137W. doi: 10.1016/j.cep.2020.108137 . ISSN   0255-2701.
  17. 1 2 3 "Market Study: Propylene (2nd edition), Ceresana, December 2014". ceresana.com. Retrieved 2015-02-03.
  18. ↑ Budavari, Susan, ed. (1996). "8034. Propylene". The Merck Index, Twelfth Edition. New Jersey: Merck & Co. pp. 1348–1349.
  19. ↑ J.G.L., Fierro (Ed.) (2006). Metal Oxides, Chemistry and Applications. CRC Press. pp. 414–455.
  20. ↑ For example, "MAPP-Pro"
  21. ↑ Heggs, T. Geoffrey (2011-10-15), "Polypropylene", in Wiley-VCH Verlag GmbH & Co. KGaA (ed.), Ullmann's Encyclopedia of Industrial Chemistry, Weinheim, Germany: Wiley-VCH Verlag GmbH & Co. KGaA, pp. o21_o04, doi:10.1002/14356007.o21_o04, ISBN   978-3-527-30673-2 , retrieved 2021-07-09
  22. ↑ Olivier-Bourbigou, H.; Breuil, P. A. R.; Magna, L.; Michel, T.; Espada Pastor, M. Fernandez; Delcroix, D. (2020). "Nickel Catalyzed Olefin Oligomerization and Dimerization" (PDF). Chemical Reviews. 120 (15): 7919–7983. doi:10.1021/acs.chemrev.0c00076. PMID   32786672. S2CID   221124789.
  23. ↑ PubChem. "Hazardous Substances Data Bank (HSDB): 175". pubchem.ncbi.nlm.nih.gov. Retrieved 2021-07-09.
  24. ↑ Bio-based drop-in, smart drop-in and dedicated chemicals
  25. ↑ Duurzame bioplastics op basis van hernieuwbare grondstoffen
  26. ↑ Guzman, Doris de (12 October 2012). "Global Bioenergies in bio-propylene". Green Chemicals Blog. Retrieved 2021-07-09.
  27. ↑ Encyclopedia of Chemical Technology, Fourth edition, 1996, ISBN   0471-52689-4 (v.20), page 261
  28. ↑ Marcelino, N.; Cernicharo, J.; Agúndez, M.; et al. (2007-08-10). "Discovery of Interstellar Propylene (CH2CHCH3): Missing Links in Interstellar Gas-Phase Chemistry". The Astrophysical Journal. 665 (2). IOP: L127–L130. arXiv: 0707.1308 . Bibcode:2007ApJ...665L.127M. doi: 10.1086/521398 . S2CID   15832967.
  29. ↑ "Spacecraft finds propylene on Saturn moon, Titan". UPI.com. 2013-09-30. Retrieved 2013-11-12.
  30. ↑ "Cassini finds ingredient of household plastic on Saturn moon". Spacedaily.com. Retrieved 2013-11-12.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.