Propylen

Propylen, commonly known as propylene or propene, is an unsaturated hydrocarbon and the simplest alkene with three carbon atoms. Its chemical formula is C3H6 and the structure CH2=CH-CH3. It is a colorless gas at room temperature, with a boiling point of -42.1 °C, and is typically stored and transported as a liquefied gas under modest pressure.

Propene is produced on a large scale in petrochemical complexes by steam cracking of heavier hydrocarbons such as propane, naphtha, or gas oil. It is also generated in refinery processes and can be separated from other products in cryogenic distillation. In addition to direct use as a fuel in some contexts, it serves as a major industrial feedstock.

Propene readily undergoes addition reactions across its double bond and polymerizes to form polypropylene, one of the most common plastics. It is also a starting material for several important chemicals, including propylene oxide, the cumene process to phenol and acetone, and acrylonitrile after further processing.

Handling and safety: propene is flammable and can form explosive mixtures with air. Vapors are heavier than air and may travel along surfaces. Storage requires inhibitors to prevent unwanted polymerization and proper ventilation; exposure should be minimized due to health and environmental concerns.

Occurrence: in small amounts it occurs in natural gas and crude oil; the bulk is produced commercially for the chemical industry.