2169.     MANKASH, E. K., BORISOVA, G. P., OROCHKO, D. I., AND FROST, A. V.  [Kinetics of Catalytic Cracking of Paraffin Over Activated Aluminum Silicate.]  Neftyanoe Khoz., vol. 24, No. 6-7, 1946, pp. 26-34; Chem. Abs., vol. 41, 1947, p. 2879.

        Cracking of wax (a Fischer-Tropsch product melting 28°-42°, mol. wt. 320) in a reaction tube packed with activated Al silicate catalyst conforms closely to equations for a unimolecular, consecutive reaction.  The velocity constant decreases slightly at low feed rates.  The apparent energy of activation, calculated from these equations, is 13,550 for the overall decomposition of the feed, 16,400 for the decomposition of cracked gasoline, 11,900 for the formation of gasoline, and 15,000 cal. per mol. for the decomposition of the residue recycled to the 2d pass.  The difference in the values for decomposition and formation of gasoline explains why maximum yield of gasoline is lower with increase in temperature.  Formulas are derived for calculating the velocity constants of catalytic cracking as a function of temperature.  Calculated data on the yield of products and the optimal volumetric velocity corresponding to maximum gasoline yield are tabulated along with experimental values.  They agree fairly well.

        MANN, C. A.  See abs. 2122.