Method for continuously producing diols from aldehydes by means of Raney cobalt catalysis

Process for continuous production of C4-C10 diols from C3-C9 aldehydes comprising the process steps of:

• a. base-catalyzed addition of formaldehyde onto C3-C9 aldehydes to obtain the corresponding hydroxyaldehydes;
• and,
• b. subsequent hydrogenation of the hydroxyaldehydes to afford the corresponding diols, characterized in that the hydrogenation of the hydroxyaldehydes is performed continuously in the liquid phase over an active cobalt hydrogenation catalyst in the presence of hydrogen without workup of the reaction mixture from the process step a);
• wherein the active cobalt hydrogenation catalyst comprises an alloy composition of about 25% to about 80% cobalt, metal selected from the group consisting of iron, nickel, chromium, rhodium, ruthenium, osmium, iridium, platinum, palladium and mixtures of these metals, with the remainder of the alloy composition being an alkali-soluble metal selected from the group of aluminum, zinc, magnesium and silicon, and dopant metals selected from the elements of groups Ib, Ilb, IVb, VIb, VIIb and VIII of the periodic table.