2029.     LACHINOV, S. S.  [Reduction of Iron Catalysts Used in the Synthesis of Ammonia.  I.  Investigation of the Reduction Process.]  Jour. Appl. Chem. (U.S.S.R.), vol. 10, 1937, pp. 19-34 (in German, pp. 34-35); Chem. Abs., vol. 31, 1937, p. 4457.

        “L-1” Fe catalyst is not completely reduced by the N-H mixture below 475°, though the reduction process may cease in the presence of O adsorbed by Fe.  The velocity of reduction increases with the increase of temperature, according to the Arrhenius law in K=C-(A/RT), where K is the velocity constant, A is the change of the energy in calories, and C is an integration constant.  The following formulas can be used for all practical purposes:  (1)yx^0.22=1,000, at p=100 atm. and Cv=15,000 cal. and (2) yx^0.117 =805, at p=100 atm. and Cv=30,000 cal., where y is temperature and x is time in hours; both formulas represent a parabolic relation between temperature and time.  The velocity of the reduction of an Fe catalyst also increases with increase of the volume velocity of the stream of N-H mixture and can be represented for the “L-1” catalyst by a straight line at the velocity of 1,000-10,000, by a parabola at 10,000-25,000, and by a hyperbola at 25,000-90,000.  The general equation for this catalyst at p=100 atm. and t=375°-500° is (15.8x+y-11,522) (8.6X10^-8 x^-2.39-y) (0.6x²-196x+20,120-y)=0, where x is the time of reduction in hours, and y is the volume velocity.  The velocity of reduction increases first with increase of the pressure, but the increase of the pressure inhibits the reduction at the end of the process.  12 refs.