3162.     SERGIENKO, S. R.  [Mechanism and Relative Rapidity of the Aromatization of Paraffinic Hydrocarbons.  I.]  Bull. acad. sci. U.R.S.S., classe sci. chim., 1941, pp. 177-190; Chem. Zentralb., 1942, I, p. 2219; Chem. Abs., vol. 37, 1943, p. 3064.

        Octane and 1:1 mixtures of octane and heptane have been aromatized in the presence of Cr₂O₃-CoO and Al₂O₃-Cr₂O₃-CoO catalysts at 475°-500° and a through-put of 0.15-0.3 vol. % of the starting material per vol. of catalyst.  By periodic regeneration (after every 2-12 hr.) of the catalyst, it will retain its original activity after 700 working hr.  Under these conditions, octane is aromatized 1.5 times more rapidly than heptane.  Depending on the reaction temperature, the throughput and the nature of the starting material, about 25-60% is converted to aromatics.  The proposed reaction scheme agrees with the multiple theory of Balandin.  By the use of oxide catalysts, the course of aromatization is through olefin intermediate products.  With Pt catalysts, no olefin intermediates are formed.  Along with aromatization, a partial cracking takes place, and the latter increases with increasing molecular weight of the aliphatic hydrocarbons.