2622.     PETERS, K., AND MEYER, K.  [Thermal Formation of Acetylene From Methane.]  Brennstoff-Chem., vol. 10, 1929, pp. 324-329; Chem. Abs., vol. 24, 1930, p. 484.

        Possible reactions are:  (1) 2CH₄→C₂H₂+3H₂-91 cal.; (2) 2CH₄→2C+4H₂-41 cal.; (3) 2CH₄→1/3 (C₆H₆)+3H₂-42 cal.  Reaction (1) is favored by high temperature and low pressure.  Reaction (2) can be suppressed by short heating time.  The apparatus consisted of a glass globe with 3 tubulures, 2 of which, being coincident with the globe diameter, served to admit the gas and electric current for heating a W spiral in the center of the globe.  Reaction gases were drawn off by the 3d tubulure.  With a heating zone 20 mm. long (3 mm. wire) at 3,000° and CH₄ at 50 mm. pressure passed at the rate of 30 l. per hr., 66.5% of the CH₄ was converted into C₂H₂, no C₆H₆ being formed.  The heating time was 0.0001 sec.  These were the most favorable conditions found for reaction (1).