67. ----------------. [APPLEYARD, K. C.] Chemistry of Fischer-Tropsch Oil Production. South African Min. and Eng. Jour., vol. 50, 1940, pp. 585-587, 615-617; Chem. Abs., vol. 34, 1940, p. 5619.
Suitable catalysts and careful control of reaction temperature are of utmost importance in the reaction for the synthesis of liquid fuels. The primary reaction on which the synthesis is based may be indicated by CO+2H2 = (CH2)x+H2O+48,000 cal. where (CH2)x designates a light hydrocarbon. The operating conditions have the following effects upon the products: (1) Increasing pressure favors formation of alcohols; (2) increase of H2 in reaction gases favors formation of CH4 because of increasing saturation, unless the temperature is lowered; (3) decrease of H2 in reaction gases favors formation of olefins; (4) increasing temperature favors formation of CH4 and C; (5) catalyst metals in the order Fe, Co, Ni favor increasing saturation therefore lower olefin content; (6) presence of CO2 no influence; (7) increase in age of catalyst increases the light-oil fraction yield at the expense of heavy oil. As shown above, the gas used for the production of liquid fuel by this process consists essentially of a mixture of 1 vol. of CO with 2 vol. of H2. This gas can be produced in a number of ways from a variety of fuels. Variations in production of this synthesis gas, depending upon economic factors, availability of raw materials, and market for byproducts are discussed. The importance of complete removal of all forms of S is emphasized. Consideration is given to the most suitable catalysts Fe, Co, and Ni and the physical form in which they should be used. The flexibility of raw materials and wide variety of products that this process permits are pointed out.