768. ------. [GARBO, P. W.] (Hydrocarbon Research, Inc.). Separating Powdered Catalysts From Exothermically Reactive Gases. United States Patent 2,526,651, Oct 24, 1950; appl. Filed Aug. 2, 1945, Serial No. 608,394; 11 claims (Cl. 260-449.6).

Patent Abstracts

768. ------. [GARBO, P. W.] (Hydrocarbon Research, Inc.). Separating Powdered Catalysts From Exothermically Reactive Gases. United States Patent 2,526,651, Oct 24, 1950; appl. Filed Aug. 2, 1945, Serial No. 608,394; 11 claims (Cl. 260-449.6).

Control of exothermic reaction of gaseous suspension of unreacted vapors and powdered catalyst is achieved by introducing an agent such as NH₃, H₂S, or thiophene, which depresses the activity of the catalyst. In hydrocarbon synthesis NH₃ 5-15% by volume of CO represses the hydrogenation. For example, in synthesizing hydrocarbons using Fe catalyst, 2 or 3 fluidizing reactors, preferably decreasing capacity, are arranged serially with means for withdrawal of products between reactors. At these withdrawal points there is a preceding separation of entrained catalyst in presence of NH₃. 1/3-2/3 of the CO will be converted in the 1^st reactor, the rest in subsequent steps. In oxidation of toluene and naphthalebe, lead tetraethyl, Fe pentacarbonyl, and I vapor may be used as repressors: in oxidation of MeOH, Cl- or S-containing compounds: in destructive hydrogenation of mineral oils, steam, or O₂. 1 foreign and 13 United States patents cited.