Abstract: Olefins having from 6 to 20 carbon atoms are hydroformylated by means of a continuous process in which a) an aqueous cobalt(II) salt solution is brought into intimate contact with hydrogen and carbon monoxide to form a hydroformylation-active cobalt catalyst, and the aqueous phase comprising the cobalt catalyst is brought into intimate contact with the olefins and, if desired, an organic solvent and also hydrogen and carbon monoxide in at least one reaction zone where the cobalt catalyst is extracted into the organic phase and the olefins are hydroformylated, b) the output from the reaction zone is treated with oxygen in the presence of acidic aqueous cobalt(II) salt solution, with the cobalt catalyst being decomposed to form cobalt(II) salts and these being backextracted into the aqueous phase; and the phases are subsequently separated, c) the aqueous cobalt(II) salt solution is recirculated in unchanged form to step a), wherein the cobalt(II) salt solution has a concentration of from 1.1 to 1.

Abstract: In a process for preparing aldehydes and/or alcohols having from 6 to 30 carbon atoms by hydroformylation of olefins by means of synthesis gas in the presence of a catalyst at from 120° C. to 210° C. and pressures of from 100 to 400 bar, a reaction mixture comprising olefins, synthesis gas and catalyst or catalyst precursor is, according to the present invention, introduced at high velocity into a high-pressure reactor via a nozzle having an adjustable flow cross section.

Abstract: In a process for preparing aldehydes and/or alcohols having from 6 to 30 carbon atoms by hydroformylation of olefins by means of synthesis gas in the presence of a catalyst at from 120° C. to 210° C. and pressures of from 100 to 400 bar, a reaction mixture comprising olefins, synthesis gas and catalyst or catalyst precursor is, according to the present invention, introduced at high velocity into a high-pressure reactor (10) via a nozzle (16) having an adjustable flow cross section.