53.    ANDERSON, R. B., SELIGMAN, B., SHULTZ, J. F., KELLY, R., AND ELLIOTT, M. A.  Fischer-Tropsch Synthesis.  X.  Some Important Variables of the Synthesis on Iron Catalysts.  Ind. Eng. Chem., vol. 44, 1952, pp. 391-397; Chem. Abs., vol. 46, 1952, p. 5,291.

               Several important variables affecting the catalyst activity and selectivity in the Fischer-Tropsch synthesis include the operating temperature and pressure and the particle size and alkali content of the catalyst.  Data are presented for fused, sintered, and precipitated Fe catalysts.  The variation of synthesis rate with temperature may be characterized by an overall activation energy of 20 kcal. per mol.  The synthesis rate increased with pressure.  For a fused catalyst the rate increased linearly with pressure; however, for other catalysts the variation of rate with pressure was less than linear.  The rate increased as the particle size decreased, probably indicating that only a fraction of the surface was accessible to the reactants.  For precipitated catalysts, the rate increased only slightly with alkali content, whereas, for other types the rate increased sharply to a maximum at about 0.5 K₂O per 100 Fe.