Steady-State Operating Policies for Plants with Multiple Reactions of Equal Overall Order

A simple methodology for determining optimal steady-state operating policies for plants with recycle has been developed by Ward et al. (Ward, J. D.; Mellichamp, D. A.; Doherty, M. F. Ind. Eng. Chem. Res. 2004, 43, 3957). Heuristics were developed to classify irreversible process chemistries into two groups, bounded and nonbounded. This classification has important implications for how to design a control system and operate a chemical plant that contains excess equipment capacity. In this paper, formal rules are developed and presented for classifying a common special case of process chemistries that have multiple undesired irreversible reactions with equal overall reaction order. This new classification procedure is essential for determining the optimal steady-state operating policy for process chemistries of multiple parallel or series/parallel reactions.