DESCRIPTION

Technical Description

Distillation is used to separate liquid mixtures made up of individual liquids that are soluble in one another. Rectification refers to distillation in a counterflow. Ethanol/water is recommended as the liquid mixture for the CE 600. It is fed into the column. It partially evaporates on its way to the bottom of the column where it is heated to boiling. The mixed vapour produced then moves upwards in the column. The mixed vapour contains a higher concentration of the component with the lower boiling point (ethanol). It leaves the top of the column and is condensed using a condenser and a phase separation tank. Part of this condensate is collected in a tank as product while the rest is fed back into the column. Here, on its way downwards, it undergoes further heating and material exchange with the rising mixed vapour. This exchange causes the vapour phase to become richer in ethanol and the liquid phase to become richer in water. The liquid phase moves to the bottom and can be collected in two tanks.

A heat exchanger allows the feed to be preheated by the bottom product carried away from the column. A sieve tray column and a packed column are available. The sieve tray column has three connections at different heights for the feed. The packed column is filled with Raschig rings. The reflux ratio is adjusted using valves.

Relevant measured values are recorded by sensors, displayed and can be processed on a PC. The software also allows controlling the temperature at the top of column or at the bottom of column (evaporator).

The well-structured instructional material sets out the fundamentals and provides a step-by-step guide through the experiments. 

Learning Objectives / Experiments

- investigation and comparison of sieve tray and packed columns
  * in continuous mode
  * in discontinuous mode
  * in vacuum mode
  * with different reflux ratios
  * with different numbers of trays and inlet heights for the feed flow (sieve tray column)
- energy efficiency increase due to feed preheating
- determination of concentration profiles
- determination of temperature profiles
- pressure loss over the column