Integrated design and control of plantwide systems coupling exothermic and endothermic reactions

The problem of integrated design and control of plantwide systems coupling endothermic and exothermic reactions is addressed. Processes simultaneously carrying on the endothermic first-order reaction A → R + Q and the exothermic second-order reaction B + Q → P are considered. As the physical properties of the species involved vary, possible flowsheets are identified and feasible control strategies are suggested. Multiple steady states are detected at fixed values of the plantwide-control variables. Singularity theory is exploited to divide the space of reactor-design parameters into regions characterized by qualitatively different solution diagrams. The implications of the observed behaviour on plant controllability are thoroughly discussed.