| 摘要 |
The preparation of olefins from steam cracker or refinery C4 streams is carried out by A) if desired, extractive distillation of butadiene from the C4 stream using a butadiene-selective solvent, B) selective hydrogenation of butadienes and acetylenic impurities in the steam cracker or refinery C4 stream or the stream from step A), with simultaneous or subsequent, at least partial isomerization of 1-butene to 2-butene, C) removal of i-butene from the C4 stream obtained in step B) by reaction with an alcohol to form an ether, D) removal of oxygen-containing impurities from the C4 stream obtained in step C) using adsorber materials, E) two-stage metathesis of the butenes in the C4 stream obtained in step D) by conversion of 1-butene and 2-butene present in the C4 stream into propene and 2-pentene and subsequent reaction of the 2-pentene with ethene in the presence of a metathesis catalyst to form propene and 1-butene. |
