The Olefins are a family of unsaturated hydrocarbons containing a double bond. The double bond provides a target for chemical reaction, both with other chemicals and with other olefins. Catalysed reaction of a pure olefin stream results in the production of polyolefins. Olefins are commonly produced by high temperature pyrolysis of refinery hydrocarbon streams in steam crackers.
Ortho-Xylene is an aromatic compound with two methyl groups substituted onto the benzene ring. Ortho-xylene is recovered from a mixed xylenes stream by fractionation. Its main application is for phthalic anhydride, which is used in plasticiser production.