Relay feedback periodic control of plate columns

Cyclic distillation technology - a mini-review

“…For stripping and absorption it is easier to obtain theoretical performance. By the mid‐1980s the most promising realizations were those of Baron, Hentrich and Vogelpohl, and Matsubara …”

“…By the mid-1980s the most promising realizations were those of Baron, 7 Hentrich and Vogelpohl, 16 and Matsubara. 17 A breakthrough was recently achieved when a new type of tray especially designed for cyclic operation was invented. 18 The special trays -shown in Figs 3 and 4 -are provided with valves and sluice chambers located under the trays.…”

“…Matsubara et al proposed the use of relay feedback for control of plate columns noting that the task of periodic control of a chemical process is to keep the process in the neighborhood of a periodic state. In principle one has three ways of generating a periodic state.…”

“…Matsubara et al analyzed what for long appeared to be the best possible control, provided product composition could be measured on‐line without dynamic effects. They used the simulation example of Dale and Furzer to which the relay feedback periodic control was applied.…”

“…Both the controller of Matsubara et al and of Dale and Furzer are SISO controllers. This gives some limits in the control performance, for example fluctuations in the measured concentration following changes in the feed concentration.…”