Control of a Industrial Heat Integrated Distillation Column

Heat integrated distillation columns are used to reduce the energy consumption for separation. The heat integrated distillation columns will behave differently than two normal heat integrated distillation column. It is well known which variables to control in normal distillation columns. But for heat integrated distillation columns this is more an open issue. This work will focus on the selection of controlled variables for heat integrated distillation columns. We will use the concept of self-optimizing control (Skogestad et al. 1999) in order to select the controlled variables. This involves a search for the variables which when kept constant will give minimum operation cost. This provides us with a systematic framework for selection of controlled variables based on steady state economics. The selection of measurements is based on a controllability analysis. Finally nonlinear simulation with a rigorous model confirms our findings.