Process for hydrogenation of C9 aldehydes in at least two hydrogenation stages

A process for producing alcohols by continuous hydrogenation of C9 aldehydes in at least two hydrogenation stages, wherein

• a stream containing the C9 aldehydes to be hydrogenated is hydrogenated with a hydrogen-containing gas over an activated metal catalyst based on a nickel metal foam in the liquid phase in the first hydrogenation stage comprising at least one recycle reactor, wherein a crude product stream containing at least alcohols and unconverted aldehydes, of which a first portion is recycled and a second portion is passed to the second hydrogenation stage, is withdrawn from the at least one recycle reactor,
• the second portion of the crude product stream is hydrogenated with a hydrogen-containing gas over a supported catalyst comprising a catalytically active component and a support material in the liquid phase in the second hydrogenation stage comprising at least one reactor operated in straight pass, wherein the catalytically active component is selected from the group consisting of nickel, copper, chromium and mixtures thereof and wherein the support material consists to an extent of more than 90% by weight of an oxidic material selected from the group consisting of aluminum oxide, aluminum silicate, silicon dioxide, titanium dioxide, zirconium oxide and mixtures of two or more thereof.