| abstract |
A process for producing aldehydes by the hydroformylation of olefins with more than 3 carbon atoms, comprising the hydroformylation stage by means of a rhodium catalyst uniformly dissolved in the reaction medium, the separation of the rhodium catalyst from the product from the hydroformylation reaction and its return to the hydroformylation stage, in which the rhodium catalyst is extracted into the aqueous phase by means of an aqueous solution of a nitrogen-containing complexing agent from the group of sulphonated pyridines, sulphonated quinolines, possibly substituted sulphonated or sulphonated component-containing 2,2' bipyridines, 1,10 phenanthrolines, 1,1' biquinolines, 2,2', 6', 2'' terpyridines and porphines, and/or from the group of carboxylated pyridines, carboxylated quinolines, possibly substituted, carboxylated or carboxylated substance-containing 2,2' bipyridines, 1,10 phenanthrolines, 2,2' biquinolines, 2,2', 6', 2'' terpyridines and porphines, and the alcohol and/or aldehyde is isolated and from the extracted hydroformylation product, the aqueous rodhium-containing extract is taken to a pre-carbonylation stage and subjected to a pre-carbonylation in said stage in the presence of a substantially water-soluble organic fluid and in the presence of carbon monoxide, synthesis gas or a carbon monoxide-containing gas mixture at a pressure of 50 to 100 bars and a temperature of 50 to 180 °C, the product from the pre-carbonylation stage is separated into an organic part containing the majority of the rhodium and an aqueous phase containing the complexing agents and the organic phase for the hydroformylation of the olefin is taken to the hydroformylation stage at 50 to 100 bars and a temperature of 50 to 180 °C. |