Method for obtaining alcohols from aldehydes II

A method for preparing saturated Cn- and C2n-alcohols, where n=4, 5 and 6, comprising the method steps of

• a) providing a mixture of isomeric Cn-aldehydes where n=4, 5 and 6 comprising unbranched aldehydes, wherein the proportion of unbranched aldehydes is at least 20% by weight, based on the Cn-aldehydes where n=4, 5 and 6, and dividing the mixture into a first substream (1a) and a second substream (1b),
• b) carrying out an aldol condensation in a tubular reactor of the aldehydes present in the first substream to obtain a mixture of Cn- and α,β-unsaturated C2n-aldehydes wherein the tubular reactor comprises a mixing module which disperses the reactant aldehyde into droplets having an average diameter (Sauter diameter) of 0.2 mm to 2 mm in a process liquor comprising aqueous sodium hydroxide solution and sodium salts of carboxylic acids and has a sodium content of 0.6 to 1.75%,
• c) mixing the mixture of Cn- and α,β-unsaturated C2n-aldehydes obtained in b) with the second substream provided in a),
• d) hydrogenating the mixture of Cn- and α,β-unsaturated C2n-aldehydes and isomeric Cn-aldehydes where n=4, 5 and 6 obtained in c) with hydrogen to obtain a mixture of saturated Cn and C2n-alcohols, and
• e) separating the mixture of Cn and C2n-alcohols,
• wherein the isomer ratio of the Cn-alcohol obtained is adjusted by the ratio of the first and second substream produced in step a) and by the aldol condensation carried out in step b).