Patent ID: 8680353

Claim:
A process for preparing oligomers by continuous oligomerization of butenes, comprising a) reacting a feed stream 1) comprising 1-butene and 2-butene in a total concentration of from 10 to 70% by weight and from 20 to 60% by weight of isobutane until more than 60% by weight of the 1-butene comprised in the feed stream 1 but less than 50% by weight of the 2-butene comprised in feed stream 1 have been converted into oligomers, b) separating off the oligomers obtained in a) and optionally passing to a further work-up and the remaining residual stream is fed to work-up by distillation, c) separating off the isobutane by distillation from the remaining residual stream, d) reacting an isobutane-depleted stream obtained after the work-up by distillation c) (hereinafter referred to as feed stream 2) to form oligomers wherein feed stream 1) and feed stream 2) are different.