1. The student conducted a lab experiment to fractionally distill crude oil by heating it to separate out different hydrocarbon mixtures based on their varying boiling points. 2. Five distillate fractions were collected in separate beakers at increasing temperature ranges from 76-110°C to 245-300°C. 3. The distillate fractions had different textures, volumes, densities, and appearances that corresponded to their varying hydrocarbon compositions based on boiling point.

1. Eric Hagenimana 10thFebruary, 2015
A00015905
CHE 310
Group Members : Faustin, Oscar, Nuhu, Yusuf
LAB REPORT : Fractional Distillation of crude oil
Abstract
In this particular lab, crude oil provided was heated at high temperature at atmospheric pressure
in order to boil the crude oil. The produced vapor was passed through the condenser in order to
be collected as liquids at different temperature range and based on the color change and drop
rate. For each distillate, temperature range, color change and its texture were placed in the table.
The distillates were found to have different textures, different volume and of course different
temperature ranges. The heavier hydrocarbons were found to be in greater quantity than the
lighter ones. At the end some of the crude oil remained in the round bottom flask because they
could resist to the temperature.
Introduction
The world relies on the use of fossil fuel to generate energy that we need in our daily
activities. Crude oil dominates the other fossil fuels in its use. However, what is crude oil? Well,
crude oil is a mixture of organic and inorganic matters that have been decayed under high
temperature and pressure during a long period of time. Since crude oil is a mixture of different
compound and inorganic substance such as hydrated salts and different harmful gases, it must
undergo different separation methods. The first separation methods must be the ones of removal
unnecessary compounds such as water, hydrated salts, inorganic gases, and acids as well because
they can cause corrosion in downstream processes. After the unwanted compounds removal, the
remaining hydrocarbons undergo fractional distillation, which is basically the separation of
liquid mixture based on their different boiling points.
Material and chemicals
In this lab, some materials and chemicals have been used. Heating mantle, fractional distillation
apparatus, thermometer of 0-300oC and beakers have been used as materials while crude oil was
the only chemical which was used.

2. Procedure
Firstly, 150 ml of crude oil was put into round bottom flask. Secondly, the round bottom flask
containing the crude oil sample was fixed to the fractional distillation set up and heating mantle.
The condenser of the fractional distillation set up was connected to the source of water so as to
water may flow in and out in order to condense the vapor by exchanging heat. Five beakers were
labelled for collecting different distillates as the fractional distillation proceeding. The
temperatures of the first and last drops of each sequence of collection were recorded. Briefly, as
the first drop of a petroleum fraction is observe, record the temperature and continue to condense
in the collecting beaker until the fraction ceases to drop or drops very little; after this record this
temperature to and quickly substitute this beaker with another. This process was done until five
distillates have successfully collected.
Result and Discussion
The temperatures and different observations made are tabulated in the table below.
Distillate Temperature
range(oC )
Volume(ml) Mass
(g)
Deinsity(g/ml) Appearance Texture
1 76-110 5.5 4.22 0.767 Cloudy Light
2 110-162 13 10.0 0.769 Colorless Light
3 162-210 15 11.75 0.783 White-
yellow
Light
4 210-245 10 8.28 0.828 yellowish Less
viscous
5 245-300 31 26.25 0.840 Yellow
brown
viscous
This table reflects the different boiling points ranges of crude oil substances. It is clear that the
lighter and lower boiling points must be obtained first.
Question
1. The crude oil is formed from organic matters that have been decayed under high
temperature and pressure during a long period of time.
2. Hydrocarbons are separated from crude oil by fractional distillation. The crude oil is
heated so it vaporizes; the vapor rises and passes through the condenser, and then it is
recovered. The hydrocarbons of lower boiling points evaporate at lower temperature
while the higher boiling points hydrocarbons evaporate at higher temperature. Briefly
when any hydrocarbon reaches its boiling point range it vaporizes and condensed by
condenser and then is recovered.
3. This process depends on boiling point of hydrocarbons.
4. When hydrocarbon molecule gets bigger, its boiling point gets higher.
5. a) Flammability of hydrocarbon decreases as the hydrocarbon gets bigger; this is due to
the increase in the total number of carbon and hydrogen atoms. As the number of carbon

3. and hydrogen increases, more oxygen radicals must be available in order to burn and
destroy the molecules.
b) The viscosity of hydrocarbon increases as the size of hydrocarbon gets bigger; this is
merely due to the increase in electron density which results in increasing the dispersion
forces. And the viscosity increases as the intermolecular forces increase.
c) When a hydrocarbon molecule gets bigger, the number of electrons increases which
leads to its higher polarization ability and leads to its stronger the dispersion forces
between the molecules as well. When the intermolecular forces are strong, then it will be
harder for the molecular to escape the solid or liquid phase into a gas phase; therefore, as
the molecular size of hydrocarbon increases, the volatility decreases.
Conclusion
The fractional separation of crude oil is an essential process in the oil industries because it helps
to distinguish different categories of petroleum to be used in different uses. But before the crude
oil has to be taken to the distillation tower, it must undergo some separation to remove some
compounds like acids, gases, etc. in the lab scale, crude oil is heated and different distillates were
condensed and recovered within specific range. Those different distillates exhibit different
texture and different colors.
Reference
 Lab manual
 Samir, Matar and Lewis .F, Hatch. Chemistry of Petrochemical Process, 2nd Ed.