Process for the preparation of aliphatic alpha, omega-diols

摘要

Aliphatic 4-12C alpha , omega -diols are produced from 4-12C alpha , omega -dicarboxylic acids by esterifying the diacid with the diol then hydrogenating the resulting oligoester with excess hydrogen on a new pelletized catalyst containing oxides of copper, manganese, aluminum and Sub-Group VI metal(s). A process for the production of 4-12C aliphatic alpha , omega -diols from 4-12C alpha , omega -dicarboxylic acids comprises oligo-esterification of the diacids with the diols to give a diol-dicarboxylate with an average chain length (n) of 3-4.5 and an acid number of 40-60 mg KOH/g, followed by liquid-phase catalytic hydrogenation of the oligoester. Hydrogenation is carried out at 180-250 (preferably 190-240) degrees C at a hydrogen pressure of 100-400 (preferably 150-300) bar with 20-100 times the stoichiometric amount of hydrogen, on zinc oxide-free catalyst pellets consisting of pressed powders of copper, manganese and aluminium oxides and at least one oxide of a Sub-Group VI metal.