Dynamics & Control of Distillation Columns

Consists of a review of column design followed by a detailed study of the control and dynamics of columns. Topics include principles of design & operation of packed bed and plate types of distillation column; vapour liquid equilibria, tray design, operating lines, number of theoretical stages, stage efficiency, significance of reflux ratio: dynamic models of the distillation process; vapour & liquid flow lags, composition lags, classical assumptions, effective XY curve, mass balances in deviation form, state space model of simple column: strategic control considerations; cut and separation, degrees of freedom, economic incentives: conventional strategies for column control; primary measurements, inferential measurement, mass and energy balance schemes, dual composition control, Ryskamp scheme, feedforward control, pressure control, internal reflux control, override control, etc.: application of modern column control techniques; steady state and dynamic decoupling, model based predictive control, optimisation of column performance.

Coursework consists of demonstrations and simulation exercises on the control and dynamics of distillation columns based upon pre-developed models. [details]