Presentation on liquid-liquid extraction

1. COMSATS LAHORE
CHEMICAL ENGINEERING DEPARTMENT
PRESENTED BY:
UMER FAROOQ
BEC-FA11-093
Liquid Liquid Extraction

2. What is liquid liquid extraction?
 The separation of the components of a liquid
mixture by treatment with a solvent in which one
or more of the desired components is preferentially
soluble is known as liquid–liquid extraction.

3. Choice of solvent
 Distribution coefficient
 Selectivity (Separation Factor)
 Insolubility of Solvent
 Density
 Recoverability
 Viscosity, Vapour Pressure, Freezing Point
 Chemical Reactivity
 Availability and Cost

4. Single stage Batch Extraction

5. Extraction is preferred on Distillation
 Distillation would require excessive amounts of heat,
such as, e.g, when the relative volatility is near unity.
 When the formation of azeotropes limits the degree
of separation obtainable in distillation.
 When heating must be avoided.
 When the components to be separated are quite
different in nature.