974.    ---------------.  [FISCHER, F AND BAHR, H.]  [Decomposition of Methane at Various Temperatures on Various Catalysts.]  Ges. Abhandl. Kenntnis Kohle, vol. 8, 1929, pp. 274-279; Chem. Zentralb., 1930, I, p. 31; Chem. Abs., vol. 25, 1931, pp. 2411-2412.

     When a gas mixture rich in CH₄ (natural gas from Altengamme with 92.5% CH₄) was conducted through a heated quartz tube or through a heated porcelain tube, which was empty or filled with porcelain fragments, the decomposition started at 850° with deposition of C on the tube walls and with the formation of H₂, tar mist, and a slight quantity of small C₁₀H₈ crystals.  When moist CH₄ is used, the quantity of the H₂ formed is almost twice that with dry CH₄ (34.3:19.1%).  With finely distributed graphite as a catalyst, no tar and only very little C₁₀H₈ is formed.  With BaSO₄ as a catalyst H₂O and H₂S are formed at 630°-650°; in this case also traces of an unsaturated hydrocarbon were noticed.  The latter was also obtained when BaO was used.  CH₄ is also decomposed when its presence in the gas current amounts to only 15%; in this case traces of C₆H₆ were noticed, which was identified as PhNO₂.  When ZnO with addition of 1% K₂O in the form of K₂CO₃ was used, the CH₄ decomposition began at 700°; at 850° the increase in volume of the gas was 50.9% and remained the same when the velocity of the current was reduced from 2-5 l. per hr. to 0.5 l. per hr., but it was considerably lessened when the velocity of the current was increased to 6 l. per hr.