distillation 1. distillation simple laboratory distillation industrial distillation fermentation and...
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DISTILLATION
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Distillation
• Simple laboratory distillation
• Industrial distillation
• Fermentation and distillation
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Distillation
How would you separate the yellow liquid from the green mixture?
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Distillation
• Yellow bp = 100oC• Blue bp = 80oC• Green bp = 100oC• How do we get to Blue liquid out of
the Green mixture?
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Distillation
• Distillation can separate one liquid from another
in a mixture solution
• Distillation works by evaporating one of the
liquids from the solution
• It is then cooled and condensed into a separate
container
• The other liquid is left behind
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Distillation
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Distillation
• Distillation is used to purify a compound by
separating it from a non-volatile or less-
volatile material
• When different compounds in a mixture have
different boiling points they can be separated
into individual components by distillation
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DistillationWhere is distillation used?
• Distillation is used to separate crude oil into
specific fractions, such as petrol or kerosene
• Water is distilled to remove impurities (e.g. salt
from seawater)
• Air is distilled to separate it into O2 and N2
• Distillation of fermented solutions has been used
since ancient times to produce beverages with a
high alcohol content
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Distillation
• Distillation is a method of separating mixtures based on
differences in their boiling points
• Distillation is a physical separation process and not a
chemical reaction
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Distillation
Simple Laboratory distillation apparatus
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DistillationSimple laboratory distillation
apparatus
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Distillation
• Boiling points are measured by recording the temperature
(within a specific range) on a thermometer while
performing a distillation
• The distillation method of boiling point determination
measures the temperature of the vapours above the liquid
• These vapours are in equilibrium with the boiling liquid and
are the same temperature as the boiling liquid
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Distillation
• The boiling point: temperature at which the vapour pressure of the liquid phase of a solution equals the external (atmospheric) pressure acting on the surface of the liquid
• The vapour pressure: is an indication of a liquid's evaporation rate. It relates to the tendency of particles to escape from the liquid
• A substance with a high vapour pressure at normal temperatures is referred to as volatile
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Distillation
• The vapour pressure of the liquid will increase as the temperature of the liquid increases
• These vapours are in equilibrium with the boiling liquid and are the same temperature as the boiling liquid
• When the vapour pressure equals the atmospheric pressure the liquid will boil
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Distillation
• Different compounds boil at different
temperatures because each has a different,
characteristic, vapour pressure
• Compounds with higher vapour pressures will
boil at lower temperatures (i.e. first to distil)
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Distillation
Industrial Distillation
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Distillation
Large scale industrial distillation
applications are required for:
• petroleum refineries
• petrochemical and chemical plants
• natural gas processing plants
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Distillation
• Industrial distillation is performed in large,
vertical, cylindrical columns known as
distillation towers or distillation columns
• Diameters: 65 cm ~16 m
• Heights: 6 m ~ 90 m or more
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Distillation
http://www.schoolscience.co.uk/content/4/chemistry/fossils/p7.html
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Distillation
• Industrial towers use reflux to separate products
• Reflux: down flowing liquid provides cooling and condensation of the up flowing vapours
• Fractions collected at specific parts of the tower
• The more reflux that is provided the better the tower's separation of lower boiling materials from higher boiling materials
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http://www.schoolscience.co.uk/content/4/chemistry/fossils/p7.html
Fraction: a group
of compounds
with boiling
points & carbon
chains within a
given range
Distillation
• Fractionating columns use trays to help separate the mixture by allowing the mixed vapors to cool, condense, and vaporize again
• With each condensation-vaporization cycle the vapors are enriched in a certain component
• A larger surface area allows more cycles, improving separation.
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Distillation• When the process feed has a diverse composition (e.g. crude oil)
outlets at intervals up the column allow for the withdrawal of
different fractions collected on trays having different carbon
chain lengths and boiling ranges
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Distillation
The lightest products
(lowest boiling point)
exit from the top of the column
The heaviest products
(highest boiling point)
exit from the bottom of the column
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Distillation
Fermentation and distillation
Distillation
• Ethanol fermentation is a biological process in which
sugars such as glucose, fructose, or sucrose are
converted into cellular energy
• The metabolic waste produce are ethanol and carbon
dioxide
• Yeasts perform this conversion in the absence of
oxygen: ethanol fermentation is anaerobic
• Ethanol fermentation occurs in the production of
alcoholic drinks, biofuel, and bread
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Distillation
• A distilled beverage, liquor, or spirit is
an alcoholic beverage containing ethanol
(CH3CH2OH)
• Produced by distilling (i.e. concentrating
by distillation) ethanol produced by means
of fermenting grain, fruit, or vegetables
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Distillation
• A still is a apparatus used to distill miscible
or immiscible liquid mixtures by heating to
selectively boil and then cooling to condense
the vapor
• Stills are used to produce beverages
containing ethanol (CH3CH2OH)
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DistillationFermentation and distillation
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Distillation
Conclusion• Distillation is a process of physically separating
mixtures
• Difference in vapour pressure and boiling point
• Used in the laboratory, industry, and in the
fermentation process
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Questions
1. What are the similarities and differences between the 3 methods of distillation?
2. Why is temperature range related to purity?
3. Would a mixture distil quicker or slower in a vacuum?
4. Design an experiment to separate 3 liquids from a mixture