Azeotrpic Distillation is carried out for the separation of component/s from an azeotropic solution. The technique for this kind of separation is to add a third substance to the solution which will forms an azeotrope with one or more components in the mixture, creating a good enough relative volatility difference for the component to be separated. The added component will be present on most of the plates of the column in appreciable concentration.
Example:
Let's take an example of an azeotropic solution of ethanol-water. To separate water from ethanol, add a third substance benzene. A termary azeotrope is formed with a boiling point of 338K, that is less than that of the binary azeotrope, 351K. This addition of relative non-polar benzene entrainer serves to volatilize water, a highly polar molecule, to a greater extent than ethanol, a moderately polar molecule and a virtually pure ethanol product may be obtained.
Example:
Let's take an example of an azeotropic solution of ethanol-water. To separate water from ethanol, add a third substance benzene. A termary azeotrope is formed with a boiling point of 338K, that is less than that of the binary azeotrope, 351K. This addition of relative non-polar benzene entrainer serves to volatilize water, a highly polar molecule, to a greater extent than ethanol, a moderately polar molecule and a virtually pure ethanol product may be obtained.
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