1816.  ------. [KEITH, P. C.] (Hydrocarbons Research, Inc.). Process for Hydrocarbon Synthesis. United States Patent 2,472,377, June 7, 1949; appl. filed Jan. 31, 1945, Serial No. 575,417; 7 claims (Cl. 260-449.6). Chem. Abs., vol. 43, 1949, p. 7213.

Synthesis gas is passed up through a powdered-Fe catalyst in a number of tubular reaction zones which become 1 at their upper and lower ends. The catalyst fills the merging zones as well as the reactor tubes. The tubes are surrounded by coolant, such as H₂O, Dowtherm, or mercury, and may be elliptical, square, polygonal or circular in shape. The preferred size for the pipes is not less than 1 in. and not more than 2 in. in internal radius. The farthest catalyst particle must be not less than 1/2 in. and not more than 4 in. away from the closest wall of the tubular zone. The linear velocity of the gases ranges 0.5-1.5 ft. per sec. In the merging zones the velocity may be as low as 0.03 ft. per sec. or even lower. A relatively dense mass of catalyst in the upper zone acts as a stabilizing cap and the mass in the bottom zone as an emergency reservoir to supply catalyst promptly to any reaction tube. A standpipe or equivalent connection between the upper and lower zones likewise helps insure good fluidization. 8 United States patents cited.