Quadratic Dynamic Matrix Control of Hydrocracking Reactors

Quadratic Dynamic Matrix Control (QDMC) has been successfully implemented on four multibed reactors in a refinery hydrocracker unit. The primary control objective is regulation of reaction severity, as measured by the Weighted Average Bed Temperature (WABT). The WABT is controlled by manipulation of individual bed average temperatures. The secondary objective, which may be selected on-line, is either to control the temperature profile or to minimize energy. Model identification and controller design are discussed. Performance of the final control system is demonstrated.