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Patent Abstracts

      937.  HART, M., HOOG, H., AND WEEDA, K. A.  (Shell Development Co.).  Reactivation of Cobalt Oxo Catalyst.  United States Patent 2,529,236, Nov. 7, 1950; appl. filed May 1, 1948, Serial No. 24,667, in the Netherlands May 2, 1947; 3 claims (Cl. 252-416).  Chem. Abs., vol. 45, 1951, p. 2607.

            Gives method for reactivation of Co catalyst used in carbonylation of organic compounds by the Oxo process.  The catalyst is subjected to a very high temperature (700º-900º C.) oxidation followed by a high temperature reduction, 400º or above.  Over a pumice stone catalyst containing 8% Co, olefins and water gas were passed at a pressure of 200 atm. and 140º-180º, giving a product containing 65% alldehydes.  Co was added to the olefin feed as Co salts of C₆-C₉ fatty acids from oxidation of aldehydes formed in an amount to give 0.15-0.25% Co in the olefin feed.  After 700 hr. the aldehyde content of the product has decreased to 25-30%.  Hydrogenation of the catalyst at 475º and 200 atm. gave only partial reactivation, the product then containing 55% aldehydes, which decreased to 25%, at which point hydrogenation was ineffective in reactivation.  Superficial oxidation of a portion of this catalyst followed by repeated hydrogenation, did not improve its activity.  Another portion of this catalyst was heated in air for a few minutes at 700º-900º and subsequently reduced with H₂ at 475º and atmospheric pressure giving a catalyst that yielded a product containing 68% aldehydes.  Before the reactivation treatment the catalyst contained less than 0.5% C and only a trace of S, and its low activity could not be attributed to those nor to the Cu content of the catalyst near the inlet, since it is know that Cu is not harmful and in any case would not have been removed in reactivation.  6 United States patents cited.