Continuous diabatic free-radical solution polymerization reactors: Search engines for non-linear dynamical solutions

Two search engines are presented to calculate both periodic and aperiodic oscillations in a continuous diabatic free-radical polymerization reactor model. The first algorithm consists of a traditional direct search stochastic procedure that uses direct integration of the process model, while the second algorithm incorporates a new eigenvalue analysis to locate Hopf bifurcations and speed-up the searching process with help of stochastic procedures. The second algorithm presents a better performance in respect to the computational time required for the searching process and allows the identification of a larger number of distinct nonlinear responses, also enabling the detection of different types of complex dynamics for this polymerization system. Particularly, the energy balance of the reactor cooling jacket is also taken into account and is shown to affect significantly the nonlinear responses of this chemical system, which had not been characterized in previous studies. (c) 2021 Elsevier Ltd. All rights reserved.