Dynamic simulation and control of chemical processes
This report concerns the application of nonlinear control techniques to the quality control of distillation columns. The required model is a set of mixed algebraic and differential equations to represent distillation columns dynamics. This model may be easily written from physical considerations but its complexity (due to its great order, or number of differential equations) prohibits its use for robust control purposes. It is therefore reduced by singular perturbations techniques, leading to a so-called aggregated model of lower order. Then nonlinear control techniques are applied which enable the rejection of feed composition disturbances and maintain the product qualities in narrow neighbourhoods of their set points. The control law is a static feedback one computed by nonlinear perturbation rejection techniques. This law leads to a stable overall closed-loop system around every slowly varying reference trajectory. Moreover, it is computed from measurements commonly available on distillation columns : the products compositions and inner temperatures. Industrial implementations on one depropaniser and one debutaniser of ELF-FRANCE show the energy savings provided by such a control technique.
Bibliographic Reference: EUR 12495 EN (1990) 38 pp., MF, ECU 4, blow-up copy ECU 5
Record Number: 199010449 / Last updated on: 1994-12-01
Original language: en
Available languages: en