843.    ERDELY, A., AND NASH, A. W.  Catalysts Used in the Synthesis of Higher Hydrocarbons From Water Gas.  Jour. Soc. Chem. Ind., vol. 47, 1928, No. 32, pp. 219-223T; Chem. Abs., vol. 22, 1928, p. 3818.

     A continuation of Elvin’s experiments (abs. 816).  From the experiments with different unpromoted catalysts at 285°, and with a gas mixture containing equal parts of CO and H₂, a Co-Cu-ZnO catalyst appears to be most suitable.  After the initial period, its activity was very constant, causing a contraction of about 50% for several days continuous operation.  A Co-Cu-Al₂O₃ catalyst gave nearly as satisfactory a performance, although less oil and more H₂O was formed in its presence.  The oil yield was highest with an unpromoted Co-Cu catalyst, although the activity of this catalyst decreased more rapidly.  A Co-Cu-CeO₂ catalyst gave the lowest yield of H₂O and a fair yield of oil, but although the initial activity of this catalyst was the greatest, its activity decreased about as rapidly as that of the Co-Cu.  Catalysts supported on silica gel were as active as the Co-Cu-Mn catalyst only in 1 instance.  In this connection, the importance of the relative proportions of catalyst to support was shown.  The optimum temperature for the formation of liquid hydrocarbons was found to be 280°-290° for the Co-Cu-Al₂O₃ catalyst.  Above 290° CO₂ and CH₄ are the chief products, and below 230° no reaction was observed.  An excess of H₂ in the initial gas mixture increased the H₂O formation, while an excess of CO rapidly decreased the activity of the catalyst.  The gas velocity exerts a marked influence on the yield of products.  The optimum space velocity for the Co-Cu-ZnO catalyst was about 120 vol. of gas per hr. per unit vol. of catalyst.