Periodic forcing of the CSTR: An Application of the generalized II‐criterion

Nonlinearities give the opportunity to influence the time average performance of a system by periodic forcing of external parameters. In this article, this concept is applied to the following reactions occurring in a continuous stirred tank reactor: A → B, A → C; A ⇋ B; A → B → C; and A → B, A + B → C. It is shown, using a generalized II‐criterion, that if the activation energies satisfy the constraint E 1 > E 2 , then the yield of B is improved using high‐frequency periodic perturbations in the temperature regardless of reaction order and operating conditions. Conversely, if E 1 > E 2 , then high‐frequency forcing always leads to a deterioration of the yield. There exist regions of parameter space where low‐frequency forcing may lead to an improvement. Results valid for low and intermediate frequencies are developed and can be used to predict additional areas of parameter space of interest for periodic operation.