| 摘要 |
A new process for the conversion of a 4C olefinic cut into isobutene and propylene, is claimed. The cut contains particularly di-olefins, 1-butene, 2-butene, isobutene and acetylenic compounds : the process incorporates the following stages: (1) Selective hydrogenation of the di-olefins and acetylenic impurities with isomerisation of 1-butene into 2-butene, to produce an effluent containing mainly 2-butene and isobutene with practically no di-olefins or acetylenics; (2) Separation by distillation of a head cut containing mainly isobutene and 1-butene (non-converted from the first stage), and a bottom cut containing mainly 2-butene and butane, with 1% maximum of isobutene and 1% maximum of 1-butene; (3) Metathesis of the 2-butenes , from stage (2), with ethylene in the presence of a catalyst comprising an oxide of Rh on a support, at 0 - 100 degrees C. and a pressure equal to the vapour pressure of the reaction mixture at the reaction temperature.The effluent contains propylene, the metathesis being followed by a separation of the propylene. Also claimed, is the installation for effecting the process. |
