Determination of optimal design and control decisions for reactor-separator systems with recycle

Abstract

Two simple yet powerful techniques used within a new model-based methodology for integrated process design and control (IPDC) to determine optimal design decisions are presented. These are attainable region (AR) and driving force (DF) techniques whose concepts are used to find the optimal design targets as an alternative to the use of optimization/search algorithms. Accordingly, the optimal solution to the design problem is to be found by locating the maximum value of AR and DF for reactor and separator units respectively. For control problem, the minimum value of the derivative (concentration in AR or DF) with respect to manipulative variables provides an optimal solution, which ensures process controllability and resiliency as well as determines controller structure selection. While other optimization algorithms may or may not able to find the optimal solution, depending on the performance of their search algorithm and computational demand, the use of AR or DF concept is simple and able to find at least near-optimal design (if not optimal) to integrated design and control problems. In this paper, we demonstrate successfully the potential use of AR technique in finding the optimal solution for the integrated design and control of a single reactor for the synthesis of ethylene glycol.