Process for the selective preparation of DIB from an i-butene-containing C4 stream

摘要

The invention relates to a process for preparing diisobutylene (DIB) from an i-butene-containing C4 raffinate I, in which the C4 stream is passed through a first hydroisomerization reactor (A) and a fractionation column (B) and is thus largely freed of 1-butene and 2-butene. It is subsequently dimerized over an acidic catalyst installed in a reactive column (E). The feed stream to this reactive column contains not only i-butene but also butanes which make the reaction temperature in the fixed bed controllable by removal of the heat of reaction. In the fractionation column (B), a side stream can be subjected to a further hydroisomerization in a reactor (C).