1. LIQUID-LIQUID
EXTRACTION
MODELS/APPLICATIONS

2. EQUILIBRIUM RELATIONSHIPS
• PHASE RULE FOR LLE
C P 2
FOR 3 COMPONENTS / 2 PHASES
3 2 2 3
• VARIABLES INCLUDED
– PRESSURE
– TEMPERATURE
– 4 COMPOSITIONS (2 IN EACH PHASE)

3. LLE DIAGRAMS - FORMS
• LLE CAN BE PRESENTED IN
VARIOUS FORMATS
– TRIANGULAR, CARTESIAN,
McCABE-THIELE
Cehreli, S.; Bilgin, M,
.Quaternary Liquid-Liquid
Equilibrium of Water + Acetic
Acid + Propionic Acid + Solvent
(Amyl Alcohol, Cyclohexyl
Acetate, or Toluene) Systems,
J. Chem. Eng. Data; (Article);
2004; 49(5); 1456-1459.

4. OTHER LLE PLOTS
Kim, J.-K.; Park, D.-W., Liquid-Liquid Equilibrium for the
Quaternary System Toluene + Water + Propionic Acid + Ethyl
Acetate at 25 C and Atmospheric Pressure ,
J. Chem. Eng. Data; (Article); 2005; 50(2); 625-629

5. LLE PLOTS
Kim, J.-K.; Park, D.-W., Liquid-Liquid Equilibrium for the Quaternary
System Toluene + Water + Propionic Acid + Ethyl Acetate at 25 C
and Atmospheric Pressure ,
J. Chem. Eng. Data; (Article); 2005; 50(2); 625-629

6. LLE PLOTS
• CARTESIAN SOLVENT-FREE PLOT
PERRY’S Ed. 7, PAGE 15-7

7. SINGLE STAGE LLX MODELS
• MASS BALANCES INCLUDE
OVERALL AND COMPONENT
• NEED EQUILIBRIUM DATA TO
CALCULATE EQUILIBRIUM
CHANGES
• STAGE EFFICIENCY LESS THAN
100% RESULTS IN A CHANGE IN
RELATIVE LOCATION OF xa VS xa*
EMPLOYS LEVER RULE

8. SINGLE STAGE LLX MODELS
• TYPICAL MODEL FOR PROCESS:
Pandit, P.; Basu, S., Dye
and Solvent Recovery in
Solvent Extraction Using
Reverse Micelles for the
Removal of Ionic Dyes
, Ind. Eng. Chem. Res.;
(Article); 2004; 43(24);
7861-7864.

9. MULTIPLE STAGE LLX MODELS
• MODEL USES OVERALL AND
COMPONENT MASS BALANCES
• EQUILIBRIUM DATA USED INITIALLY TO
DETERMINE MINIMUM SOLVENT (L/V)
RATIO (PONCHON-SAVARITT)
– LOCATES ya,min ON EXTENDED EQUILIBRIUM
TIE LINE PASSING THROUGH xa
– USE LEVER RULE TO DETERMINE Vb,min
• LOCALIZED EQUILIBRIUM VALUES CAN
RESULT IN ACTUAL Vb,min VALUES BEING
HIGHER AND THIS WILL BE NOTICED IN
ACTUAL DESIGN IF Ncalc = ∞

10. MULTIPLE STAGE LLX MODELS
• SEQUENTIAL FEED – NORMALLY
COUNTERCURRENT
Nishihama, S.; Hirai, T.;
Komasawa, I., Separation and
Recovery of Gallium and
Indium from Simulated Zinc
Refinery Residue by Liquid-
Liquid Extraction ,
Ind. Eng. Chem. Res.;
(Article); 1999; 38(3); 1032-
1039.

11. MULTIPLE STAGE LLX MODELS
• DESIGN IS BASED ON RATIO OF Vb,act TO
Vb,min
• USED TO LOCATE ya,act
• DESIGN POINT BASED IN INTERSECTION
OF xa-ya LINE WITH xb-yb LINE.
• STAGES ARE STEPPED OFF BY
ALTERNATING BETWEEN
INTERSECTIONS ON EQUILIBRIUM
ENVELOPE DEFINED BY EQUILIBRIUM
TIE LINES AND LINES FROM DESIGN
POINT.

12. MULTIPLE STAGE LLX MODELS
• McCABE THEILE DIAGRAM CAN BE
CONSTRUCTED FROM DATA FROM
PONCHON-SAVARITT
• ALTERNATELY, IF B & S ARE
RELATIVELY IMMISCIBLE AND
FLOWS ARE SPECIFIED, THEN
INERT FLOW MODEL CAN BE USED
FOR THE OPERATING LINE. USING
COMPONENT BALANCES FOR
SOLUTE, A:

13. MULTIPLE STAGE LLX MODELS
• INERT FLOWS MODEL
OVERALL
xa yb xb ya
L` V` L` V`
1 xa 1 yb 1 xb 1 ya
FOR INTERIM STAGE
xa yn 1 xn ya
L` V` L` V`
1 xa 1 yn 1 1 xn 1 ya
• L' = NON-TRANSFERRING B IN
RAFFINATE AND V' = NON-
TRANSFERRING S IN EXTRACT.
• CAN BE PLOTTED WITH EQUILIBRIUM
LINE ON McCABE-THIELE FOR
CALCULATIONS

14. LLX EQUIPMENT
• MIXER-SETTLERS
A+B S
EXTRACT
EXTRACT LAYER
FAFFINATE
RAFFINATE LAYER
MIXER SETTLER

15. LLX EQUIPMENT
• SPRAY TYPE EXTRACTION TOWER
Chen, Liang-Huei (Chia-Nan Coll of Pharmacy and Science); Lee, Yuh-
Lang, Effects of a surfactant on the mass transfer in spray-tower
extraction column, Chemical Engineering Journal, v 73, n 1, 1999, p 77-
81

16. SPRAY TYPE EXTRACTION TOWER
• USES A SPARGER FOR LIGHT
LIQUID AND DISPERSER FOR
HEAVY LIQUID
• OVERFLOW IS LIGHT/UNDERFLOW
IS HEAVY

17. SIEVE TRAY EXTRACTION TOWER
• SIMILAR TO DISTILLATION UNIT
J. Antonio Rocha, J. Carlos
Cardenas, Cesar Sosa, and Jorge
Rosales, Preliminary design of
sieve tray extraction columns. 1.
Determination of the column
diameter. Flooding velocities in
sieve tray extractors , Ind. Eng.
Chem. Res.; 1989; 28(12) pp
1873 - 1878

18. SIEVE TRAY EXTRACTION TOWER
• LIGHT LIQUID INVENTORIED
UNDER EACH TRAY
• BUBBLES OF LIGHT LIQUID PASS
THROUGH COUNTERFLOW OF
HEAVY LIQUID
• DOWNCOMERS ARE USED TO
TRANSFER HEAVY LIQUID DOWN
THE COLUMN

19. SIEVE TRAY EXTRACTION TOWER
• DOWNCOMER DESIGN
J. Antonio Rocha, J. Carlos
Cardenas, Cesar Sosa, and
Jorge Rosales, Preliminary
design of sieve tray extraction
columns. 1. Determination of the
column diameter. Flooding
velocities in sieve tray extractors
, Ind. Eng. Chem. Res.; 1989;
28(12) pp 1873 - 1878

20. YORK-SHEIBEL COLUMN
• YORK-SHEIBEL COLUMNUSES
AGITATION TO MIX MATERIAL FOR
EACH STAGE WITH SETTLING
OCCURING OUTSIDE THE AGITATION
ZONE

21. PODBEILNIAK CENTRIFUGAL
• PROVIDES A SINGLE STAGE HIGH
g CONTACTING
CONTACTING
REGIME
LIGHT OUT HEAVY IN
LIGHT IN HEAVY OUT

22. PROCESSES THAT UTILIZE LLX
• TYPICALLY ARE THOSE IN WHICH
DISTILLATION IS NOT ECONOMICALLY
ATTRACTIVE
• SULFOLANE PROCESS (UOP) -RECOVERY OF
AROMATICS, COMBINES DISTILLATION
WITH LLE
http://www.uop
.com/objects/5
5%20Sulfolane
.pdf

23. PROCESSES THAT UTILIZE LLX
• BIOTECH AND BIOPHARM
– SEPARATION OF HIGH MOLECULAR
WEIGHT FATTY ACIDS FROM
VEGETABLE OILS
Alfred Thomas, Fats and Fatty Oils,
Ullmann's Encyclopedia of Industrial
Chemistry
Copyright © 2002 by Wiley-VCH Verlag
GmbH & Co. KGaA
– PENICILLIN

24. PENICILLIN
PRODUCTION
PROCESS
Joseph A. Shaeiwitz,
Joseph D. Henry, Jr.,
Biochemical Separations ,
Ullmann's Encyclopedia of
Industrial Chemistry
Copyright © 2002 by
Wiley-VCH Verlag GmbH
& Co. KGaA

25. SUPERCRITICAL EXTRACTION
• SOLVENT IS AT SUPERCRITICAL CONDITIONS
• SUPERCRITICAL SOLVENT HAS
THERMODYNAMIC AND TRANSPORT
PROPERTIES THAT ARE SIMILAR TO A LOOSE
LIQUID OR A DENSE GAS.
– SOLUTE EXTRACTION BASED ON SOLUBILITY IN
SUPERCRITICAL PHASE
– PRODUCT IS OBTAINED BY LETTING PRESSURE
DOWN TO SUBCRITICAL CONDITIONS
• PROCESS DESCRIBED IN TEXT DECAFFINATION
IS MORE LIKE SUPERCRITICAL LEACHING

26. TYPICAL SC PROCESS
• Eldridge, R. B., Oil
Contaminant Removal
from Drill Cuttings by
Supercritical
Extraction, Ind. Eng.
Chem. Res.; (Article);
1996; 35(6); 1901-
1905.