3.2 Separation Power with Multiple Stages ....................16

3.3 Separation Power and Energy Consumption ...........18

3.4 Summary....................................................................20

Exercises.............................................................................21

References ..........................................................................21

4 Distillate/Feed Material Balance Split ...................23

Learning Objectives ...........................................................23

4.1 Material Balances.......................................................24

4.2 Temperature Gradient per Theoretical Stage ...........26

4.3 Temperature Change from D/F Shift ........................27

4.4 Summary....................................................................29

Exercises.............................................................................30

Reference ............................................................................31

5 Distillation Control Strategies ...............................33

Learning Objectives ...........................................................33

5.1 Column Pressure Control ..........................................34

5.2 Temperature Control with Distillate Flow Rate ........34

5.3 Temperature Control with Reflux Flow Rate............37

5.4 Temperature Control with Boilup (Steam Flow
Rate) ...........................................................................38

5.5 Temperature Control with Bottoms Flow Rate.........40

5.6 Side Draw Flow Rate.................................................41

5.7 Distillate Vapor Flow Rate.........................................42

5.8 Summary....................................................................43

Exercises.............................................................................43

Reference ........................................................................... 44

6 Constraints.............................................................45

Learning Objectives ...........................................................45

6.1 Mechanical and Hydraulic Constraints .....................45

6.2 Heat Transfer Constraints..........................................47

6.3 Stripping Mass Transfer Constraint ...........................47

6.4 Rectification (Absorption) Mass Transfer
Constraint...................................................................50

6.5 Summary....................................................................53

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