Combined preparation of at least butene and octene from ethene

Abstract

A process for the combined preparation of at least butene and octene from ethane, proceeds by a) providing an inert solvent having a boiling point or boiling range below the boiling point of butene; b) providing a first feed mixture comprising at least the inert solvent and ethene dissolved therein; c) converting the first feed mixture in a first synthesis; d) in the first synthesis, oligomerizing at least a portion of the ethene present in the first feed mixture in the presence of a first heterogeneous catalyst and in the presence of the inert solvent to obtain a first reaction mixture comprising at least the inert solvent, butene, hexene and octene; e) working-up of the first reaction mixture and/or a substance stream based thereon into a low boiler fraction comprising the inert solvent, at least one C-fraction comprising butenes, a C-fraction comprising hexenes, a C-fraction comprising octenes and into a C-fraction comprising hydrocarbons having more than eight carbon atoms; f) using at least a portion of the low boiler fraction for providing the first feed mixture; g) providing a second feed mixture comprising at least hexene and ethene dissolved in the hexene using at least a portion of the C-fraction; h) converting the second feed mixture in a second synthesis, wherein the second synthesis is spatially separated from the first synthesis; i) in the second synthesis, reacting at least a portion of the ethene present in the second feed mixture with at least a portion of the hexene present in the second feed mixture in the presence of a second heterogeneous catalyst to obtain a second reaction mixture comprising at least octene; and k) joint working-up of the second reaction mixture with the first reaction mixture or with the substance stream based thereon.