Chapter 3

Separation Power

The separation power in a distillation column is associated
with the height of the column and the energy consumed to
achieve the desired separation and purification of products.
Learning Objectives
When you have completed this chapter, you should be able to
1. Understand the origin of separation power in distillation
2. Calculate the key impurity separation power
3. Conceptualize the control of separation power with the
ratio of steam/feed or reflux/feed
4. Consider ways of minimizing energy consumption
3.1 Relative Volatility in One Theoretical Stage
The separation power in a distillation column comes from the
thermodynamic vapor–liquid equilibrium relative volatility, the
number of theoretical stages achieved by the column, and the
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