(295d) Catalytic Reactions in Various Configurations of a Two-Reactor System

A comprehensive analysis of static and dynamic behavior of catalytic reactions occurring in two coupled CSTRs is presented. The examples considered pertain to a catalytic reaction exhibiting inhibition kinetics and generation of an autocatalyst from a primary resource followed by its decay. Autocatalytic reactions and processes are commonly encountered in growth of all living cells, processes involving free radicals, polymerization processes, many inorganic and organic reactions, and crystallization processes. A single well-mixed reactor may operate at up to three steady states and can give rise to limit cycles for an autocatalytic reaction. The reactors in the two-reactor system may be identical only in terms of feed composition and reactor space time. The reactors need not have identical volumes and volumetric feed, effluent, and exchange rates. A two-reactor system may admit up to nine steady states at least at very low interaction rates. Three of these steady states, symmetric steady states, correspond to identical composition in the two reactors. The remaining steady states, the asymmetric steady states, correspond to different composition in the two reactors and are admissible over a range of interaction rates. The six asymmetric steady states exhibit four different pairing sets with two or more limit points. Numerical illustrations reveal the rich steady state structure of the reaction scheme in coupled reactors. The steady states are tracked systematically as the interaction rate is varied. The catalytic reaction exhibiting inhibition kinetics does not lead to periodic states in two-reactor systems. Numerical illustrations for autocatalytic reaction in two-reactor systems on the other hand reveal phenomena such as extinction or synchronization of oscillations and chaotic operation through period doubling. The two-reactor system is operationally more flexible and more robust vis-a-vis single reactor. Emergence of additional steady states for both reaction examples and higher order periodic states and aperiodic states at intermediate values of interaction rates for an autocatalytic reaction reveals that two-reactor systems involving these reactions are an example of a complex system.