Process for producing an alcohol by alkoxycarbonylation of diisobutene with prior distillation and subsequent hydrogenation

A process for producing a target alcohol, the process comprising:

• (a) supplying a diisobutene stream, comprising 2,4,4-trimethylpent-2-ene and 2,4,4-trimethylpent-1-ene, to at least one distillation column, and separating the diisobutene stream into at least one overhead stream that is enriched with 2,4,4-trimethylpent-1-ene compared to the diisobutene stream used and contains more than 85% by weight of 2,4,4-trimethylpent-1-ene, and a residual stream depleted in 2,4,4-trimethylpent-1-ene compared to the diisobutene stream used;
• (b) supplying the at least one overhead stream to an alkoxycarbonylation whereby 2,4,4-trimethylpent-2-ene and 2,4,4-trimethylpent-1-ene are in a reaction zone reacted with an alcohol and carbon monoxide in the presence of a homogeneous catalyst system, comprising at least one metal of group 8 to 10 of the periodic table of the elements or a compound thereof, a phosphorus-containing ligand and an acid to obtain a liquid product mixture, the liquid product mixture comprising at least one ester formed by the alkoxycarbonylation, the homogeneous catalyst system, unreacted 2,4,4-trimethylpent-2-ene and 2,4,4-trimethylpent-1-ene and unreacted alcohol;
• (c) removing the homogeneous catalyst system from the liquid product mixture to obtain a crude product mixture, comprising at least the ester formed by the alkoxycarbonylation, unreacted 2,4,4-trimethylpent-2-ene and 2,4,4-trimethylpent-1-ene and unreacted alcohols;
• (d) distillative processing of the crude product mixture in at least one distillation column to remove the unreacted alcohols and the unreacted 2,4,4-trimethylpent-2-ene and 2,4,4-trimethylpent-1-ene, wherein unreacted alcohol and the unreacted 2,4,4-trimethylpent-2-ene and 2,4,4-trimethylpent-1-ene are removed and recycled to the alkoxycarbonylation in (b);
• (e) hydrogenating the ester obtained in (d) with hydrogen in the presence of the heterogeneous catalyst system in a hydrogenation zone to obtain an alcohol mixture comprising at least the target alcohol, the eliminated alcohol and unreacted esters;
• and
• (f) removing the target alcohol formed in (e) in at least one separation step selected from the group consisting of thermal separation, extraction, crystallization and membrane separation.