Propylene, with the structural formula CH₂=CHCH₃, is the second simplest member of the olefin family. It ranks among the most important organic chemical feedstocks after ethylene and benzene. Propylene is commonly recovered from gases produced during thermal cracking and catalytic cracking processes. It is also generated as a byproduct of ethylene production through light oil cracking.

The unsaturated carbon-carbon double bond in its molecular structure allows propylene to participate in addition reactions with hydrogen, halogens, and hydrogen halides, as well as in addition polymerization. As a key chemical raw material, propylene is widely used to manufacture acrylonitrile, polypropylene, ethylene-propylene rubber, propylene oxide, acetone, and other synthetic resins. It is also an important feedstock for producing synthetic rubber, synthetic fibers, and plastics.

Product Application of Propylene

Propylene is a vital raw material in the chemical industry and serves as a major feedstock for producing a wide range of downstream chemicals. Through gas-phase oxidation, propylene is converted into acrolein, which can then be used to produce acrylic acid, allyl alcohol, glyceraldehyde, hydroxyacetaldehyde, and methionine, an important additive for food and animal feed.

When propylene undergoes ammoxidation, it produces acrylonitrile, a key raw material used in the manufacture of synthetic fibers, synthetic rubber, and plastics. Chlorination of propylene yields chloropropylene, which can be further processed into allyl alcohol, propylene dichlorohydrin, chloropropionitrile, and other intermediates. These compounds are used in the production of glycerin, epoxy resins, chlorohydrin rubber, and surfactants.

Propylene is also used in alkylation processes to produce cumene, the primary intermediate for phenol production, with acetone obtained as a valuable co-product. Through oxo synthesis, propylene produces n-butyraldehyde and isobutyraldehyde, which are important intermediates in the manufacture of plasticizers, dyes, solvents, pesticides, and other organic chemicals.

Furthermore, hydration of propylene produces isopropyl alcohol, which serves as a raw material for manufacturing acetone, isopropylamine, and isopropyl esters. Propylene can also undergo dimerization, trimerization, polymerization, and tetramerization to generate valuable products, including ethylene, propylene trimers, polypropylene, and dodecene. Dodecene is an important intermediate in surfactant production.