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

Abstract

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.

Shortcut Method for Initialization of Dividing‐Wall Columns and Estimating Pareto‐Optimal NQ‐Curves

“…1c. This kind of column is to be built at Ulm University with the purpose to be suited for a broad range of mixtures 13, 30. Thus, the theoretical stages in all sections are set equal and double in section C32.…”

Shortcut Method for Initialization of Dividing Wall Columns and Estimating Pareto-Optimal NQ-curves

“…The mixture is assumed to be split in a simplified multiple dividing wall column as shown in Figure 1c. This kind of column is to be built at Ulm University with the purpose to be suited for a broad range of mixtures [13,30]. Thus, the theoretical stages in all sections are set equal and for fluid dynamic reasons double in section C32.…”

Dynamic Control of Liquid-Only Transfer Stream Agrawal Divided-Wall Column

“…However, ADWC has multiple degrees of freedom, and the variables are highly coupled to each other, which poses great difficulties for the precise control of ADWC. Scientific researchers have successively proposed composition control, temperature control, , temperature–composition mixing control, and temperature difference control. , Most of the control structures adjust only liquid split ratios in the process control, assuming the vapor split ratios as the steady-state design value. But fixed vapor splitting ratios cannot guarantee minimum energy consumption in the face of feed disturbances .…”