Process for producing alcohols

A process for producing alcohols, to obtain a straight-chain alcohol having a carbon number of n (where n=4 to 5), a branched-chain alcohol having a carbon number of n (where n=4 to 5) and a branched-chain alcohol having a carbon number of 2n (where n=4 to 5) from a mixed aldehyde comprising a straight-chain aldehyde having a carbon number of n (where n=4 to 5) and a branched-chain aldehyde having a carbon number of n (where n=4 to 5) in an optional proportion, which comprises supplying the mixed aldehyde to a distillation column, withdrawing from the bottom of the column an aldehyde rich in the straight-chain aldehyde, dimerizing the straight-chain aldehyde, followed by hydrogenation to obtain the branched chain alcohol having a carbon number of 2n, while obtaining, as a fraction from the top of the column, an aldehyde rich in the branched-chain aldehyde and having a straight-chain aldehyde concentration in the fraction of at least 30 wt %, subjecting the fraction to hydrogenation, and purifying and separating the resulting straight-chain and branched-chain mixed alcohol to obtain the straight-chain alcohol having a carbon number of n and the branched chain alcohol having a carbon number of n, respectively, the mixed aldehyde as the starting material being one obtained by hydroformylation of butene and/or propylene.