HYDROFORMYLATION PROCESS INCLUDING CATALYST RECYCLE

An improved hydroformylation catalyst cycle is disclosed wherein the cobalt catalyst is recycled to the hydroformylation reaction mainly as a water soluble carbonyl salt, obtained from extraction of the acidic form of the homogeneous cobalt carbonyl catalyst from the hydroformylation product with an aqueous solution of a salt of a weaker acid. The organic product after extraction is submitted to a further demetalling step in the presence of a dilute acid and an oxidant. The water from this further demetalling step is suitable for use in the upstream extraction step. A free water phase present in the hydroformylation reaction product may be separated upstream from the extraction step and is suitable for use in the further demetalling step, such that the catalyst cycle has no waste water stream.