摘要 |
The preparation of olefins from steam cracker or refinery C4 streams is carried out by selective hydrogenation of butadienes and acetylenic impurities in the steam cracker or refinery C4 stream, with simultaneous or subsequent, at least partial isomerization of 1-butene to 2-butene, followed by removal of i-butene from the C4 stream by reaction with an alcohol to form an ether, followed by removal of oxygen-containing impurities from the C4 stream using adsorber materials, followed by two-stage metathesis of the butenes in the C4 stream 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. Optionally, butadiene may be removed from the C4 stream by extractive distillation in a preliminary step. |