Influence of longitudinal mixing on the degree of reactant conversion in a chemical flow reactor

Abstract

The method of small perturbations in the approximation of a “weak” chemical reaction (low dimensionless reaction rate) is used to obtain, to terms of third order, an approximate analytic solution to the problem of the concentration distribution in a one-dimensional chemical flow reactor. This solution makes it possible to analyze the dependence of the degree of conversion of the original reactant on the longitudinal diffusion and other factors. An autocatalytic reaction, in which the degree of conversion depends nonmonotonically on the Peclet number, is considered as an example. The investigation shows that for different values of the parameters of the problem longitudinal mixing can both increase and decrease the degree of conversion. The results make it possible to identify ranges of variation of the parameters which characterize the operation of the reactor in which longitudinal mixing has different influences on the degree of chemical conversion and find the degree of longitudinal mixing which ensures optimal operation of the chemical reactor.