Control of Quaternary Ideal Endothermic Reactive Distillation with and without Internal Heat Integration

Decentralized control system design is evaluated for a basic and an internally heat-integrated generic, ideal, double-feed, two-product reactive distillation system. The internally heat-integrated reactive distillation column (HiRDC) is obtained via catalyst redistribution into the rectifying zone and feed tray relocation. For basic regulatory control, three two-point control structures with a fixed reflux rate or a fixed reflux ratio operation policy are synthesized and evaluated for their closed-loop disturbance rejection characteristics using rigorous dynamic simulations. To eliminate the purity offsets for on-target product purities, product purity composition controllers manipulating the reflux ratio and stripping tray temperature set point are implemented. Reactive tray section composition control is necessary for on-target product purity operation of HiRDC.