Real Time Computer Data Acquisition and Control Systems: An Application to Model Reference Adaptive Control of a Packed Bed Tubular Reactor

Abstract

<p>A pilot scale non-adiabatic packed bed reactor has been designed and constructed to carry out the hydrogenolysis of n-butane over a nickel on silica gel catalyst. The complex reaction scheme is highly exothermic and results in steep radial gradients within the reactor. The apparatus was interfaced to a minicomputer. A sophisticated executive program was developed to assist with on-line studies of the apparatus. It provided measurements of axial and radial reactor temperatures and composition data for the reactor effluent. A third order, discrete time state space model of the reactor was postulated from mechanistic arguments and the parameters fitted to dynamic data. The model served as the basis of a derivation of a model reference adaptive controller designed to satisfy Lyapunov's second theorem of stability. The control algorithm included terms for proportional, integral and setpoint actions. The objective of the controller was to regulate the reactor's production rate of intermediate reaction species. The control algorithm was implemented experimentally and its performance discussed. Problems with the controller are examined and recommendations made.</p>