Liquid-Liquid Extraction on a Right-Triangle Ternary Phase Diagram
This Demonstration shows how to use the Hunter–Nash method on a right-triangle ternary phase diagram. Check "grid lines" to show grid lines on the diagram. Check "carrier compositions" to show the carrier mass fractions on the diagram. The Hunter–Nash method uses material balances and a ternary phase diagram with phase separation to determine the number of equilibrium stages needed for liquid-liquid extraction (LLE). The solvent mass flow rate and the desired raffinate (refined product) composition RN are given. Select "plot points" and then drag the black feed point (labeled with a circled F) to a desired feed composition within a restricted range of compositions. Use buttons to view the compositions of the feed F, solvent S or raffinate RN in the solute (blue), solvent (red) and carrier (green) phases. Select "mixing point" to see how the mixing point M and the extract composition E1 in the first stage are determined. Check "show E1" to show the extract composition. Next, select "operating point" to show how the operating point P is found. This also displays a schematic of the flow system and mass balances. The operating point is used to determine the number of stages. Finally, select "count stages" to use the "draw tie lines" slider to determine the number of stages and the extract and raffinate compositions in each stage. The solid orange lines follow the black tie lines, and the dashed blue lines trace back to the operating point. A diagram of the stages is shown above the ternary phase diagram.
