Loci of Forced Cycling Operation and Transient Chemical Oscillation in Heterogeneous Catalysis*

A mathematical model to analyse the forced cycling response and the self oscillation in heterogeneous catalysis is proposed for a tubular flow reactor, and a computer simulation technique is applied to evaluate the validity of model proposed. .A typical E-R model reaction and hydrogen oxidation on a thin nickel foil are employed as a concrete subject. When the stimulus of the sine-function and the step function of reactants are introduced into the differential reactor, the mode of the response curves of products al the outlet of the reactor is sensitively affected by the desorption rate of the products. It is exactly confirmed that the reactor efficiency to produce the objective products is not affected by the forced concentration cyclic operation. Slinko’s model for the computer simulation is satisfactorily applied to visualize the self oscillation resulting from the change in the rate constants which vary with the suriace coverage of the adsorbed species. The concentration of the reactants and the exponential factors of rate constants have a drastic effect on the appearance of oscillation restricted by the specified ranges of their magnitude. The locus of the transient oscillation caused by the concentration jump is clearly displayed and characterized depending on the amplitudes and the frequencies.