Distillation is a physical process of separating the component
substances from a liquid mixture based on differences in the boiling
point of the components of the mixture.
There are many types of distillation :
- Simple distillation.
- Fractional distillation.
- Vacuum distillation.
- Flash distillation.
- Azeotropic distillation.
Liquid is boiled and the vapours of the more volatile components are condensed and liquefied.
It is the same process of simple distillation but it has a fractionating column to achieve pure distillates.
It is used when the boiling point of the compound is too high to distil the compound without significant decomposition.
the process of separating or purifying a substance by removing the solvent quickly. It is used to desalinate seawater.
It is based on adding a compound that forms an azeotrope with at
least one of the components of a mixture which can be more readily
What's the distillation main tool?
Distillation column is an essential item used in distillation of
liquid mixtures, so as to separate the mixture into its component parts
based on the differences in volatilities.
Distillation column has diameters ranging from about 65
centimetres to 6 meters and heights ranging from about 6 meters to 60
meters, or more.
There are many types of distillation column :
What's the difference between packed column and plate column?
It's used in many processes, such as removing contaminants from a gas stream
(absorption), removing volatile components from a liquid stream by
contacting it with an inert gas (stripping), and in distillation where
the separation is difficult due to close boiling components.
It's used in many processes, such as distillation, absorption and extraction.
This column consists of trays used for increasing the contact
time between the liquid and vapour to make a perfect distillation.
There are many types of trays (Bubble cap trays, Sieve trays, Valve trays)
Types of Trays that used inside the column
Bubble cap tray
It has riser or chimney fitted over each hole, and a cap that covers the riser.
The cap is mounted so that there is a space between riser and cap to
allow the passage of vapour.
Simply, they are metal plates with holes in them. Vapour passes straight upward through
the liquid on the plate. The arrangement, number and size of the holes
are design parameters.
in it, perforations are covered by liftable caps. Vapour flows lifts the caps,
thus self-creating a flow area for the passage of vapour. The lifting
cap directs the vapour to flow horizontally into the liquid, thus
providing better mixing than is possible in sieve trays.
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Temperature gradient in distillation column
In the distillation column, the temperature increases as you move down in the column.
The feed enters the furnace -before entering the distillation
column- to increase the temperature of the crude to nearly 400 °C at
The products will appear at these temperatures :
- Petroleum gas (below 30 °C)
- Gasoline (30 °C to 150 °C)
- kerosene ( 150 °C to 250 °C)
- Diesel oil (250 °C to 350 °C)
- Residue and lubricating oil (more than 400 °C)