Process and apparatus for the production of olefins

摘要

Olefin production involving converting a feed into fractions with conversion of a long-chain to a short-chain olefin fraction and conversion of the products and non-reactants to a fraction containing hydrocarbons of at most 3C which is separated off and recycled. Olefin production involving converting a hydrocarbon-containing feed in a stage (1) (especially in a refinery or olefin plant) into various fractions with conversion (12) of a fraction containing long-chain (at least 4C) olefins into short-chain olefins and passage of the reaction products and non-reactants to a conversion stage (17) to give a fraction containing hydrocarbons with at most 3C which is separated off and recycled to stage (1), is such that at least a part of the fraction obtained in stage (17) and containing more than 3C is fed to a paraffin-olefin separation stage (23), with at least part of the separated paraffin being recycled to stage (1) or drawn-off and utilized and at least part of the olefin being recycled to conversion stage (12). An Independent claim is also included for apparatus for olefin production as above comprising a fractionating device (6) and having a paraffin-olefin separator (23) following the fractionating device (17), the separator (23) being connected via a paraffin line to stage (1) and via an olefin line to conversion stage (12).