Simple and Fractional Distillation
Institution Affiliation
Date
Table of Contents
PURPOSE
The objective is to help understand the concept of
distillation by separating a mixture of methanol and water using fractional and
simple distillation methods. Water and Methanol are miscible. Simple and
fractional distillation methods will be used to demonstrate how to separate
miscible substances. Although the distillate that is collected from this
experiment is not expected to be 100% pure, the effectiveness and efficiency of
the process will be discussed with respect to each distillation process to help
compare and determine between the two which one is more effective and why. These
experiments will help learners understand the complex industrial distillation process
done on a large scale.
INTRODUCTION
Miscible
liquids are separated through the process of distillation. A solution is heated
until it starts to vaporize, then cooled down to back to liquid. Liquids which
have different boiling point evaporates at different stages (Nicholas 2017). Simple distillation is used to separate
liquids which has a wide gap in boiling point, while fractional distillation is
suitable for separating substances which has a closer gap in boiling point. The
liquid with a lower boiling point will change to vapor first, passed through
the condenser where it turns back to liquid and is collected container as
distillate (Nicholas 2017).
EXPERIMENT PROCEDURE
Simple distillation
Apparatus required
Round bottom flask, Vacuum Adapter, Water condenser, Thermometer
adapter, Thermometer, ‘Y’Shaped multipurpose adapter, Jack, Woodblock, Clamps, Graduated
cylinder, Boiling chip, Water tube and Heating mantle.
Preparation for Simple distillation
I.
Set up the
apparatus above as shown in fig 1.1
Figure
1.1 a complete
set-up of apparatus for simple distillation
II.
put 20ml methanol
and 20ml water in round bottom flask
III.
Add a boiling chip
to the mixture
IV.
When the set up is
complete turn on the water and the heat source.
Observations from simple distillation experiment
I.
The table below
contains the reading of the Volume of distillate after every 2ml against their
respective temperature.
|
Vol ml
|
0
|
2
|
4
|
6
|
8
|
10
|
12
|
14
|
16
|
18
|
20
|
22
|
24
|
25
|
|
Temp (°C)
|
63.4
|
63.7
|
65
|
66.3
|
67.8
|
68
|
70
|
70.8
|
72.8
|
75.5
|
78.2
|
83.3
|
87.8
|
88.6
|
Fractional distillation
Apparatus required
Round bottom flask, Vacuum Adapter, Water condenser, Thermometer
adapter, Thermometer, ‘Y’ Shaped multipurpose adapter, Clamps, Graduated
cylinder, Boiling chip, Water tube, Heating mantle, Fractional column.
Preparation of Fractional distillation
I.
Gather all the
apparatus required and set-up a fractional distillation as shown in fig 1.2
below.
Figure
2.1 complete
set up of apparatus for fractional distillation.
II.
Mix water 20ml and
Methanol 20ml into a round bottom flask.
III.
Add a boiling chip
into the mixture.
IV.
Switch on the
heating mantle to Start heating the mixture.
V.
Connect the water
source and ensure that cold water is continuously running through the
condenser.
VI.
Continue heating
the solution even after it start boiling.
VII.
Once the first
drop is collected in the graduated cylinder, read the temperature on the
thermometer.
VIII.
Take the reading
of the thermometer after every increment of the distillate in 2ml.
IX.
After all the
readings are taken, disassemble the apparatus once they cool down.
Observations from fractional distillation experiment
a) The table below contains the reading of the Volume of
distillate after every 2ml against their respective temperature.
|
Vol ml
|
0
|
2
|
4
|
6
|
8
|
10
|
12
|
14
|
16
|
18
|
20
|
22
|
24
|
25
|
|
Temp (°C)
|
58
|
60
|
60.7
|
61.5
|
62.3
|
63.1
|
63.9
|
65.0
|
66.7
|
68.0
|
73.8
|
86.2
|
90.8
|
91.3
|
DISCUSSION
Graphical illustrations
Distillation Process
Add
20ml water and 20ml methanol into a round bottom flask, then set-up the
apparatus as shown in fig 1.1. Start heating the mixture by adjusting the power
knob that supplies power to the heating mantle. Continue heating the mixture
until it boils. Ensure a continuous flow of cold water through the condenser. Take
note of the temperature when the first drop falls to the graduated cylider.
Continue recording the temperature after the distillate increases at an
interval of 2ml in the graduated cylinder.
Differences between simple distillation and fractional distillation
Fractional distillation is a more complex process that
uses fractional column while simple distillation is a simpler process and the
fractional column is not used. The reason why the fractional column is used in
distillation is to separate a mixture of fluids which has a relatively closer
boiling point (Mia et al. 2017).
Explanation of Observations from the Graphs
The first drop in the fractional distillation came out
at 580C while that of simple distillation came out at 63.40C.
Also, both lines increase at almost the same gradient up to at around 20ml
after which the gradient for fractional distillation becomes steeper as
compared to that of simple distillation. This implies that most of the all methanol
had vaporized and the remaining solution has to be heated harder for it to
vaporize.
Boiling point of methanol
From the graphical illustrations, both graphs have two
different boiling points. The boiling point of methanol is 63.4 0C
in simple distillation and 580C in fractional distillation. 64.70C
is the accepted boiling point for methanol (Jerry et al. 2014).
Contrary to my expectation, the accepted boiling point
at 64.70C is closer to the boiling point of methanol at simple
distillation. This should not have been the case if the error discussed
hereunder wasn’t there. The boiling point of fractional distillation should
have been closer to the accepted boiling point because it does not have the
fractional column which contains steel wool or glass beads meant to increase
the surface area. This makes the vapor to condense and return back to the
boiling mixture many times before vaporizing and reaching the topmost of the
column, due to the aspect of condensing and re-vaporizing the boiling point reading
becomes more accurate than that of simple distillation method.
Waste Disposal
At the end of our distillate, we need to dispose of
the distillate into the non-halogen organic solvent bin. After disposing we
should ensure that the bottle where we put the waste is closed always.
Safety Protection and Precaution
Methanol is poisonous and therefore, after the
experiment one should always wear lab coats, Protective eyewear, gloves, and closed-toe
shoes at all times when experimenting. It is also highly flammable and
therefore one should take caution not to sprinkle it so as not to cause fire.
We should not eat anything in the laboratory as it might be contaminated and dispose
properly laboratory waste (Peter 2016).
1n 1926, the federal government intentionally
increased the amount of methanol used in industrial alcohol to poison alcohol
in an attempt to curb alcohol consumption.
Distillation of Ethanal
Ethanal can be distilled from a mixture of water using
both methods because they have different boiling points (Jerry et al. 2014).
Distillation Real-world applications
a)
Separation of oil
products
Crude oil comprises different petroleum products,
these petroleum products in crude oil have different boiling points and
therefore they are separated using fractional distillation (Sukasem, Hareemao, & Sudawong. 2017).
b)
Distillation of
salty water
A large distillation plant can be used to purify salty
water and supply many people with clean drinking water and also be used to
cook.
The precision of the Thermometer
The precision of the thermometer is the fraction to
which a thermometer can be read, it can also be defined as the nearest whole
number or decimal to which a thermometer can be read. In our experiment the precision of the
thermometer is 0.10C.
Errors and Omissions in the experiment
There was a critical error made during the transition
from simple distillation to fractional distillation. The instructor did not
completely change the entire set of apparatus he used for simple distillation.
Instead, he only added a fractional column and proceed with the experiment on
fractional distillation.
CONCLUSION
Distillation is the most commonly used method of
separating a mixture of two or more liquids. The process applies a simple rule of
separating mixtures based on their boiling points. It has traditionally been
used to perform complex industrial separation of substances in the food
industry, chemical, and petroleum industry. It should be understood that
distillation is an irreversible process, and is commonly used alongside other
procedures to ensure that the distillate is 100% pure.
REFERENCES
Pater, L. (2016). The
mimic of fractional distillation technology distillation process modeling. arXiv preprint
arXiv:1605.00097. Jerry . M., David
G. A., Gretchen E.
Mia, M., Islam, A.,
Rubel, R. I., & Islam, M. R. (2017). Fractional distillation & of
tire- derived pyrolysis oil.
Sukasem, N., Hareemao,
T., & Sudawong, C. (2017). The mimic of fractional distillation technology for
the development of homegrown pot distillery for ethanol distillation. Energy Procedia, 138, 985-990.
Jerry R., Paul F. S., &
Christina N. H. (2014) Laboratory Techniques in Organic Chemistry. Library of Congress Control Number: 2013955847
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