CONSTRAINED NONLINEAR MULTIVARIABLE CONTROL OF A CATALYTIC REFORMING PROCESS

A constrained nonlinear multivariable control and optimization strateg y fbr handling constraints has been proposed and applied in real time to a catalytic reforming reactor-section. A dynamic model of the catal ytic reforming process was developed and used in a nonlinear multivari able control application on the reactor section to provide target valu es for the reactor inlet temperature. The model results were tested in a real-time application, and the results were used to improve the dyn amic response of the model. The constrained nonlinear multivariable co ntroller controls the weighted average inlet temperature (WAIT), while respecting the heater tube temperature constraints. WAIT is set by an octane inferential model forming a closed-loop WAIT/octane quality co ntrol. (C) 1998 Elsevier Science Ltd. All rights reserved.