Uses a solvent to separate components.
A solvent immiscible with the feed extracts a solute by selective solubility; distribution coefficient K=y/x guides solvent choice. Equipment: mixer-settlers, columns. Use ternary diagrams to design. Suits heat-sensitive or close-boiling mixtures and pharmaceuticals.
Caffeine is extracted from coffee using supercritical CO₂ or ethyl acetate.
Liquid-liquid extraction separates components that cannot be distilled easily, such as heat sensitive or close boiling compounds.
Uses a solvent to separate components.
Liquid-liquid extraction separates components that cannot be distilled easily, such as heat sensitive or close boiling compounds.
The ratio of concentrations in the two liquid phases at equilibrium, which determines how much solute goes into the extract.
High selectivity for the target, low solubility in the feed liquid, easy recovery, and low cost and hazard.
Typical applications include recovering a pharmaceutical from a fermentation broth using a solvent, removing acetic acid from water with an organic solvent and separating metals in hydrometallurgy using a selective extractant.
Study "Absorption and stripping" first (topic 74 of 100 in Materials & Chemical). It covers the groundwork this topic builds on.
Raffinate and extract. Selectivity. Solvent recovery.
Caffeine is extracted from coffee using supercritical CO₂ or ethyl acetate.
The next topic is "Adsorption", which builds directly on this one.
It is classed as Advanced in Materials & Chemical (topic 75 of 100). It is an advanced topic. It assumes you are comfortable with the intermediate topics in Materials & Chemical.
Want to practise? Open the interactive course for quick checks, quizzes, simulations and progress tracking.