Propylene
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Propylene".

Propene
IUPAC name	Propene
Identifiers
CAS number	[115-07-1]
UN number	1077 In Liquefied petroleum gas: 1075
RTECS number	UC6740000
SMILES	C=CC
Properties
Molecular formula	C3H6
Molar mass	42.08 g/mol
Appearance	colorless gas
Melting point	− 185.2 °C (88.0 K)
Boiling point	− 47.6 °C (225.5 K)
Solubility in water	0.61 g/m3 (? °C)
Viscosity	8.34 µPa·s at 16.7 °C
Structure
Dipole moment	0.366 D (gas)
Hazards
MSDS	External MSDS
Main hazards	Highly flammable, Asphyxiant
NFPA 704	4 1 1
R-phrases	12
S-phrases	9-16-33
Flash point	−108 °C
Related compounds
Related groups	Allyl, Propenyl
Related compounds	Propane, Propyne Allene, 1-Propanol 2-Propanol
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Propene, also known as propylene, is an unsaturated hydrocarbon having the chemical formula C₃H₆. It is the second simplest member of the alkene class of hydrocarbons, ethylene (ethene) being the simplest.

Propene is a colourless and flammable gas at room temperature and pressure. It is also odourless, so (as with most other gaseous hydrocarbons) it is mixed with minute quantites of mercaptans, sulfurous compounds with a powerful garlic smell to make it more easily detectable. It is found in coal gas and can be synthesized by cracking petroleum or by the dehydrogenation of propane. Propene is a major commodity in the petrochemicals industry, where its main use is as a monomer in production of polypropylene. It is also an intermediate in the production of various chemicals including acetone, isopropanol, acrylonitrile, and propylene oxide.^[1] Propene is also used as a fuel gas for various industrial processes. It has a similar calorific value to propane, but a lower mass of combustion products, so it has a higher flame temperature. Propylene also has significantly higher vapour pressure than propane at room temperature.

Since it is generally produced from coal or petroleum, it is a non-renewable resource, and if used as a fuel, it is classified as a fossil fuel.

Recently H₂O₂/propylene has been proposed as an approach to inexpensive Single Stage To Orbit: a fuel tank containing propylene has a bladder floating in it containing H₂O₂. This combination offers 15% superior I_sp to O2/RP4 (a kerosene used as rocket propellant), does not need turbines or cryogenic storage or hardware, and greatly reduces the cost of the booster. The potential of this and other alternative systems is discussed in some detail at Dunn Engineering.

References