Modeling distillation column nonlinearity for μ-synthesis

Distillation columns show a highly nonlinear behavior. To design a satisfactory controller for the whole operating range using μ-synthesis, an uncertainty model representing column nonlinearity as exactly as possible is most important. Based on the example of an industrial binary distillation column a new method for modeling the distillation column nonlinearity is discussed. The resulting controller performance is illustrated by simulation results for the whole operating range.