Distillation: The Forgotten Art

Distillation: The Forgotten Art

Jacob Arredondo, and Jonathan Worstell

Distillation may not be a glitzy, glamorous unit operation these days, but is still remains important with regard to profit generation in the chemical industry. For that reason, it should be taught in undergraduate laboratory courses. However, distillation experiments have a size limitation, which is determined by the amount of solvent stored in the laboratory.

To relax this size limitation, we have designed three-day laboratory sequence. During the first day, senior students batch distill one of several binary organic mixtures using bench top equipment. They do a flash, empty column, packed column, three-valve column, and six-valve column distillation; then analyze their results using Lord Rayleigh’s equation and McCabe-Theile diagrams.

The second day, students operate a three-tray air/water Plexiglas column that has interchangeable sieve, valve, and bubble cap trays. The students determine the flooding and weeping operating regime for each type of tray.

Finally, during the third day, the students distill their assigned binary mixture in a twenty five tray Oldershaw column. They control this column manually, which is a good learning experience.

This presentation includes a video demonstration of the second day’s experiment using the Plexiglas column.