Investigation of Control Structures for a Four‐Product Laboratory Multiple Dividing‐Wall Column Using Dynamic Simulation

• Published in: Chemical engineering & technology 2021-02, Vol.44 (2), p.223-237
• Main Authors: Preißinger, Ulrich, Lukač, Goran, Dejanović, Igor, Grützner, Thomas
• Format: Article
• Language: English
• Subjects: Column control; Distillation; Dividing wall columns; Dividing‐wall column; Dynamic simulation; Flow velocity; Four‐product column; Pilot plants; Robust control
• ISSN: 0930-7516; 1521-4125
• DOI: 10.1002/ceat.202000557

The dynamic behavior of a multiple dividing‐wall column pilot plant is evaluated by means of dynamic simulation. Three different control structures are developed or adapted from the literature, which are constrained by the actual design features of the pilot plant column. Since in the present case the design of the column was chosen such that very different mixtures can be separated, it cannot be optimally designed for each of these potential mixtures. Rather, the design focused on the flexibility of the plant. All three investigated control structures were tested on feed flow rate and feed composition disturbance and allowed a robust control of the pilot plant, whereby control structure 2 is slightly better than others in terms of steady‐state deviations and less pronounced fluctuations during the dynamic phase. The transferability of control structure 2 to other variants of multiple dividing‐wall columns is easily possible. Multiple dividing‐wall columns offer high investment and energy cost savings in distillation. To ensure these savings during operation, robust control structures must be applied. Three basically simple and practical control structures were investigated for a simplified multiple dividing‐wall column. All three control structures allow a robust control of the laboratory column.