Nonlinear Control Structures for Chemical Reactors

A nonlinear feedback controller for chemical reaction dynamic systems is examined in which the control action is a function of the deviation of the reaction rate from steady state. The motivations for this controller are (i) the finding that the reaction rate sensitivity to composition and temperature deviations is closely associated with the slow or unstable dynamic modes for the reaction systems studied to date; (ii) the controller nonlinearity mirrors the principal process nonlinearity; and (iii) such a control law is intuitively meaningful. In this paper, we develop the controller and propose a nonlinear analysis method for an idealized model of the continuous stirred tank reactor.