954.    ---------------.  [FISCHER, F.]   [Synthesis of Aromatic Hydrocarbons From Methane at Atmospheric Pressure and Without Catalysts.]  Brennstoff-Chem., vol. 9, 1928, pp. 309-316; Chem. Abs., vol. 23, 1929, p. 2694.

      Pure CH₄ from various sources and CH₄ with other gases (coal gas) is decomposed by passage through porcelain or quartz tubes heated 900°-1,200°.  The tar formed is precipitated by a Cottrell precipitator, and light oils are absorbed by active charcoal.  The time of contact is fully as important as the temperature.  For example, 346 l. CH₄ 89% with 8% N₂ passed through the 1-mm. annular space between concentric 14- and 16-mm. tubes 22 cm. long at 63 l. per hr. gave 7 gm. oil, 3 gm. tar, and 0.2 gm. C.  Higher temperatures with the same gas flow favor precipitation of C.  Tar and oil do not form to an appreciable extent below 900°.  The tar is aromatic; naphthalene, anthracene, and phenethrene being isolated.  The oils contain mostly benzene with xylene and C₁₀H₈.  SiO₂, W, Mo, and Sn as catalysts did not favor oil yields; Fe, Cu and graphite favored C precipitation.