Liquid Liquid Extraction

Liquid- Liquid- Extraction

Lecturer: Thomas Gamse

ao.Univ.Prof.Dipl.-Ing.Dr.techn.

Department of Chemical Engineering and Environmental Technology

Graz University of Technology

Inffeldgasse 25, A-8010 Graz

Tel.: ++43 316 873 7477

Fax: ++43 316 873 7472

email: Thomas.Gamse@TUGraz.at

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Lecturer: Dr. Gamse

Examples Liquid - Liquid Extraction

Nominating of the flows

Solvent

Feed

Mixer

Separator

Raffinate

Extract

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Example 1: Ternary Systems, Triangle Diagram

Two mixtures R and E, which contain both the three compounds A, B, and C, have to

mixed in the ratio 1:2. This ternary system has no miscibility gap so that all

compounds are completely soluble each other. The mixture R has a composition of

x A , R = 0,7 and x B , R = 0,2 ; the mixture E exists of x A , E = 0,1 and x B , E = 0,5 .

Please determine:

a) The points R and E in the triangle diagram and the concentration of the

active agent C and

b) the mixing point (calculation and graphical determination).

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a.) Mixtures in the triangle diagram

For a partial solubility of substances A and B, which is essential for extraction, all

three compounds have to be taken into account for drawing of the phase equilibrium.

For this reason triangle co-ordinates are used, where each of the vertexes represents

the pure compounds. Points at the triangle side represent the composition of the

binary system and points inside the triangle the composition of the ternary system.

The representation of a ternary point is based on the fact that the sum of the normal

distances in a equal sided triangle is corresponding to the height of the triangle. If the

height of the triangle is set 100% so result the concentrations of the single

compounds from the normal distances (see figure).

The given points R and E...