Abstract
In order to analyze the reaction performance and enhance the selectivity of industrial catalytic processes with fluidized-beds, the direct contact model for consecutive reaction proposed previously is extended theoretically to be applicable to parallel consecutive reactions. From mathematical derivation, it is shown that the reaction performance in a parallel consecutive reaction, such as the conversion of raw material and the yield and selectivity of intermediate product, can be obtained by use of the basic reaction model for a consecutive reaction by introducing a factor for parallel reaction and a simple relationship between reaction rate constants in the parallel consecutive reaction and those for the consecutive reaction model. By comparing with reported conversion and selectivity data in industrial processes of propylene ammoxidation, the reaction performance simulated by the proposed model was in good agreement with the data. From this investigation, it is also concluded that the synergy effect of basic parameters, such as the ratio of reaction rate constants in the consecutive reaction step, Nrr, the ratio of the mass transfer capacitance coefficient to the reaction rate constant, Nmr , and the proportion of direct contact catalyst-particles in the total catalyst-particles in the reactor, on the reaction performance is analogous to that in the consecutive reaction and essential for enhancing the reactivity and selectivity in parallel consecutive reactions.
