2045.     LAMME, N.  [Synthesis of Hydrocarbons According to Fischer-Tropsch.]  Thesis, Tech. High School, Delft, Holland, Feb. 20, 1946, 207 pp. (in Dutch); Chim. et ind., vol. 56, 1946, p. 213-214.

        2 catalysts were utilized by the author in his investigations; the Raney skeleton catalyst of Ni-Co and the precipitated Co-ThO₂-kieselguhr catalyst of Fischer.  In the synthesis, at atmospheric pressure, the best results were obtained by first reducing the catalyst and then heating it in an atmosphere of CO.  The catalyst in any case does not become active until after 5-10 days use, then it maintains its activity for 30-50 days.  The yield of product is about 50%; the ratio of oil to gasoline is about 1:1, depending upon the synthesis temperature.  The catalyst is regenerated by means of H₂.  1/3 of the reaction gas mixture is transferred into liquid and solid hydrocarbons, 1/3 into gaseous hydrocarbons, and the remainder is not converted.  At a higher temperature, a higher transformation takes place but in the form of gaseous hydrocarbons.  Under 10 atm. pressure and with the Co-ThO₂-kieselguhr catalyst the average molecular weight of the hydrocarbons formed is the same as that of the hydrocarbons obtained at atmospheric pressure.  The synthesis of CH₄ also is increased, and larger amounts of CH₄ and CO are found in the residual gases.  In the reduction of CO₂ by H₂ it is found that CO acts as a catalyst poison.  The hydrocarbons formed are mostly C₅ and C₆, their amount diminishing as the molecular weight increases; for a hydrocarbon of definite molecular weight, an increase in quantity keeps pace with the diminution in saturation.  There is no formation of cyclic compounds in the Fischer-Tropsch process.