GB690977A - Improvements in or relating to oxo synthesis - Google Patents

Abstract

Aldehydes containing dissolved cobalt compounds produced by the Oxo synthesis are treated in a catalyst removal zone with oxalic acid to precipitate cobalt oxalate. The acid may be added as a solid or dissolved in a non-aqueous solvent, e.g. ether, acetone, dioxane, or decobalted aldehyde product, if desired after dehydration. Generally a molar equivalent up to 10 per cent excess of acid is used at about 70-160 DEG F. After settling, the separated aldehyde may be filtered and water-washed, and the solvent, if used, separated by flash distillation. Removal of the solvent may, however, be effected after hydrogenation of the aldehyde to alcohol. Soluble or insoluble cobalt compounds may be added in starting up, e.g. cobalt naphthenate or oleate dissolved in the olefin feed or cobalt oxalate. Preferred conditions are 250-450 DEG F., and 2500-3500 p.s.i.g. Part of the reaction product containing dissolved cobalt, and of the suspension of precipitated cobalt oxalate prior to settling, may be recycled to the reactor.