Dynamics and Control of Distillation Columns
Objectives and Syllabus
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.
|Code:||CME 8384 (formerly ACS 684)|
|Time Allocation:||Lectures||40 hours|
|Private Study||70 hours|
|Prerequisites:||Control Schemes and Strategies (CME 8376)|
|Assessment:||By report on assignment
By 1 x 2 hour examination
To provide a comprehensive, in-depth, understanding of the principal approaches to the control of distillation columns and their principles of operation, and to understand the dynamics of columns and the interactions involved.
- To develop an understanding of the principles of the design of distillation columns.
- To appreciate the objectives and operational constraints on the control of distillation columns.
- To develop a feel for the dynamics of a distillation column, the interactions involved and the structure of dynamic models of such.
- To become familiar with a range of conventional methods of controlling distillation columns.
- To introduce modern techniques of column control and provide a basis for applying them in an industrial context.
Prerequisite to this module is the Control Schemes and Strategies (CME 8376) module.
It is desirable, but not essential, that students have completed (or have some familiarity with the material covered in) the Modelling and Simulation (CME 8380) module before doing this one.
This module is of one week's full-time intensive study consisting of a variety of lectures, informal tutorials, problem solving, case studies and structured computer-based laboratory work. It is followed by an assignment to be carried out in the student’s own time.
The time allocation for practical work provides for an exercise on column design based on the McCabe Thiel method and simulation exercises on the dynamic response and control of columns using the Matlab and Simulink packages. Pre-developed models of column dynamics will be provided as appropriate.