Distillation Columns (Fractional & Simple Distillation)

Distillation Columns

Principle

In countercurrent distillation (rectification) using a column, the rising vapour can enter into interactions with the condensate. In this manner, a fractional distillation, i.e. a distillation in several steps for the separation of substances with similar boiling points, can be performed in a single apparatus. If bubble tray columns are used condensate can be removed from the individual bubble trays.

Benefits

• Simplified implementation: all pre-settings already prepared
• Didactic gas chromatograph included
• Glass jacket system easily expandable
• Simultaneous temperature measurement at four points

Tasks

1. Investigate the mode of operation of a fractionating tower on a two-stage bubble tray column. Distil a mixture of three n-alcanes first with total reflux and then without any reflux.
2. Subsequently, examine and compare the initial mixture, the sump product, the head products and the condensates of both trays.

Learning objectives

• Bubble tray column
• Rectification
• Continuous and discontinuous distillation
• Vapour pressure
• Vaporisation
• Condensation
• Raoult’s law

Necessary accessories

• Precision balance 620g/0.001g

Software included. Computer not provided.