3720. ----- [SWEETSER, S. B.] (Standard Oil Development Co.). Process of Regenerating Synthesis Catalyst With Oxygen and Return of Oxidized Catalyst to the Synthesis Reactor. United States Patent 2,472,501, June 7, 1949; appl. filed Dec. 20, 1945, Serial No. 636,248; 3 claims (Cl. 260-449.6). Chem. Abs., vol. 43, 1949, p. 6811.

Fluid Fe catalyst used in Fischer-Tropsch synthesis is regenerated with air or O₂-containing gas. A portion of the contaminated catalyst is withdrawn from the lower part of the reaction zone either intermittently or continuously at a slow rate and transferred to a 2d fluid-type reactor where it is regenerated with air. In a continuous process the regenerator is much < the reactor. The oxidized catalyst is returned to the reactor at a very low rate, so that the ratio of oxidized material will gradually be converted to a reduced form. The rate of return of oxidized regenerated catalyst should be < 2% of the total weight of catalyst in the reactor per hr. 2 foreign patents and 4 United States patents cited.