A process for obtaining a stream of hydrocarbons comprising from 4 to 12 carbon atoms per molecule, with an increased proportion of linear α-olefins and a lower proportion of dienes compared to a feed stream of hydrocarbons comprising from 4 to 12 carbon atoms per molecule, with a content of linear α-olefins, linear internal olefins and dienes, with supply of hydrogen, wherein
- (a) the feed stream is fed to a first distillation zone D1 having at least 5 theoretical plates;
- (b) linear α-olefins are removed partly or fully as a component of a vapor stream which additionally also comprises the dienes;
- (c) and at whose lower end a liquid stream is obtained which has been depleted partly or fully of linear α-olefins;
- (d) the liquid stream from the lower end of said first distillation zone D1 is introduced into a isomerization unit which is equipped with at least one isomerization catalyst over which the linear internal olefins are isomerized partly or fully to linear α-olefins, and the linear α-olefins formed in this way are removed as a component of a vapor stream ascending into the first distillation zone D1;
- (e) the vapor stream ascending out of said first distillation zone D1 enters a selective hydrogenation unit comprising a second reactive distillation zone RD2 in which at least a portion of the dienes are hydrogenated selectively to olefins over a low-isomerization selective hydrogenation catalyst to obtain a vapor stream which is drawn off condensed fully or partly and drawn off as a product stream with an increased proportion of linear α-olefins compared to the feed stream;
- and
- (f) said distillation zone D1 and the reactive distillation zone RD2 being integrated in a single reactive distillation column RDK.