2. Introduction
• Fractional distillation is the separation of a
mixture of miscible liquids into its component
parts, or fractions based on differences on
their boiling point. The process consists of
heating the mixture at temperature at which
the components will evaporate, and the
mixture pass through a condenser where they
are cooled and condensed to a liquid again.
3. • A fractionating column is an essential item
used in the fractional distillation of liquid
mixtures so as to separate the mixture into its
component parts, based on the differences in
their volatilities.
4. Mechanism
• As a liquid mixture in the round bottom flask is boiled,
vapor rises up the fractionating column. The vapors
condense on the glass platforms (known as trays or
plates) inside the fractionating column, and runs back
down into the distillation flask. The hottest tray is at
the bottom of the column and the coolest tray is at the
top. At steady state conditions, the vapor and liquid on
each tray is at equilibrium. Only the most volatile of
the vapors stays in gas form all the way to the top. The
vapors at the top of the column then flow through the
water-cooled condenser, which cools the vapor down
until it condenses into a liquid distillate.
5.
6. Applications
• Fractional Distillation is used for:
• Separation of miscible liquids such as acetone
and water , chloroform and benzene.
• Preparation of alcohol which is one of the
most important pharmaceutical substance.
• Separation of non-volatile substance from
volatile substance.
• Purification of many organic compounds such
as ethers, amide, etc.
7. Advantage of Fractional Distillation
• It’s easy to use.
• It’s highly effective and efficient.
• It helps produce much-needed fuel
• Separates liquids with smaller boiling point
separation.
8. Disadvantages of Fractional Distillation
• It can be expensive.
• Consumes more energy
• It can contribute to environmental pollution.
• It takes longer time for liquid to distill.
