Investigation into the Change in the Composition of the Ethylbenzene Feed in a Styrene Production Reactor while Taking into Account the Partial Pressures of the Reactants

A mathematical description of ethylbenzene dehydrogenation has been developed taking into account the changes in the partial pressures and partial molar volumes of the components of the reaction mixtures. In computational experiments, a steam–ethylbenzene mixture is considered as a system of interacting gases, for which a study is made of the effect of the partial parameters of the components on the change in the component composition of the reaction medium, in the ethylbenzene conversion, in the selectivity toward the desired product, and in the rate of the decrease in the specific rection rates. It is determined that the partial molar volumes and pressures of the substances have a significant effect on the rates of the bimolecular reactions of the process and, as a consequence, on the dynamics of the formation of side products; the sensitivity of the reaction-rate constants to a change in the considered parameters decreases along the length of a reactor stage. The derived mathematical dependences relate the control parameters (ethylbenzene conversion and selectivity toward the desired product) and the physical state quantities of the contact gas. The model can be used to estimate the degree of coking of the catalyst bed during the operation of the reactor.