PATENT

3639. STEWART, M.M. (The Texas Co.).  Preparation on Nonsintered Iron Catalyst.  United States Patent 2,438, 584, Mar. 30, 1948; appl. filed Dec. 22, 1945, Serial No. 637,114; 4 claims (Cl. 252-257).  Chem. Abs., vol. 42, 1948, p.8430.

Fe catalyst for use in a fixed bed or fluid system is prepared by a simplified method, which dispenses with the high temperature fusion step usually used in forming magnetite.  Fe ore, Fe salt, or spent catalyst is placed in the reactor.  Air is passed through the mass at a temperature range 750°-875° F. to remove C and effect at least partial oxidation of metallic Fe to either the ferrous or ferric state.  The treatment is continued until C oxides are no longer found in the effluent.  Then a 50:50 mixture of air and steam 700°-800° F. is admitted to further oxidize the material to Fe₂O₃ or magnetite.  Fe₃O₄.  This treatment is continued until the composition of the gas entering the reactor is approximately the same as the composition of the gas leaving the reactor.  Air is discontinued and treatment with steam alone, 700°-800° F., to purge the catalyst of molecular O₂ is continued until the effluent is free of molecular O2.  A 50:50 mixture of steam and H₂ is introduced to convert the ferric oxide to magnetite.  This is the critical step in the treatment.  Ferric oxide would be reduced completely to metallic Fe by the H₂ were it not for the oxidizing effect of the steam.  When partial reduction is complete, as shown by similarity of composition of gases entering and leaving the reactor, the magnetite is reduced to the metallic state by H₂ alone, 700°-800° F.  Promoters such as K oxide, alumina, or magnesia enhance the activity of the catalyst.  A good composition is 2-3% alumina, 1-2% K oxide, and 95_97% metallic Fe.  This preparation or regeneration may be carried out in the same reactor in which the hydrogenation of CO takes place.  7 United States patents are cited.

----- See abs. 32, 3332.