Distillation - Principles of Chemical Separations with Environmental Applications - page 85

4

Distillation

Double, double, toil and trouble, fire burn, and cauldron bubble.
- WILLIAM SHAKESPEARE, Macbeth

4.1 Objectives

1 Describe the physical meaning of:
(a) constant molar overflow (CMO);
(b) an operating line;
(c) an equilibrium line.
2For the McCabe-Thiele graphical method:
(a) Draw an operating line for each section of a distillation column.
(b) Determine minimum and actual reflux ratios, and know the meaning of total
reflux.
(c) Handle multiple feeds and/or sidestreams.
(d) Determine the number of equilibrium stages.
(e) Given the Murphree efficiency, determine the actual number of stages required.
(f) Draw the q -line (which is a measure of the vapor and liquid content) for the feed
stream in a McCabe-Thiele diagram.
(g) Locate optimum feed plate location.
(h) Step off stages when feed is not located on optimum plate.
(i) Determine the number of equilibrium stages when using steam injection instead of
a reboiler.