Abstract: This invention concerns an oxo process, either batch or continuously operated, for the preparation of aldehydes, principally in relatively high proportions of branched isomer, from olefins and synthesis gas employing an unmodified rhodium catalyst feed or recycle such as the rhodium salts of organic carboxylic acids. More particularly the invention concerns such a process wherein at least a portion of the reaction medium, e.g., the oxo reactor effluent, is contacted with a ligandizing compound such as triphenylphosphine, prior to product recovery by distillation, such that the rhodium catalyst is converted to a stable form and not lost by plating out on the distillation column or base heater during the distillation. Thereafter, the catalyst is deligandized and regenerated by air treatment and reused in the process.

Abstract: An improved method for the preparation of aldehydes by the hydroformylation of an alpha-olefin, carbon monoxide and hydrogen in the presence of a rhodium complex catalyst at a pressure of about 1,000 psig and in the presence of from about 1% to about 10% of water.

Abstract: Rhodium hydroformylation catalysts are regenerated by a novel process which includes the steps of removing the catalyst to be regenerated from the hydroformylation reaction, adjusting the aldehyde contents of the catalyst containing stream so as to have at least one mole of aldehyde present per mole of rhodium and ligand present in the catalyst, treating the aldehyde containing catalyst stream with oxygen or oxygen containing gas at a temperature less than the boiling point of the aldehyde, removing any solid material formed during the oxidation and adjusting the ligand to rhodium ratio as required for use in the hydroformylation reaction.