2. Introduction
• The first step in refining is the seperation
of petroleum into fractions by fractional
distillation in an oil refinery. Each fraction
consistes of a mixture of hydrocarbon
molecules that boils over a range of
temperatures. For example, the
kerosene fraction is a mixture that boils
between 170 and 250 degrees celcius
4. Procedure
• A. Fractional distillation of Petroleum
1. The apparatus is set up as shown in Figure 1(b).
2. The petroleum is heated in the distillation flask.
3. The first fraction of petroleum is collected at
30°C - 80°C.
4. The heating is continued and the distillation is
collected in separate conical flasks at different
ranges of temperature at 80°C - 120°C,
120°C – 160 °C and 160°C - 200°C.
7. Procedure
• B. Characteristics of various fractions
5. The colour is observed of each fraction.
6. The viscosity of the fractions is observed by
tilting the conical flask. (Figure 2)
7. For each of the fractions, some of it was
poured into evaporating dish and it was
heated. The colour of the flame is observed
and produced soot. (Figure 3)
8. The observation is recorded.
10. Result:
•
Fraction Temperatur
Range
Colour Viscosity Flammability
Petrol 30 ° C – 80° C Colourless Flows easily
(non-
viscous)
Burns easily
Naphta 80 ° C - 120 °
C
Yellowish Slightly
viscous
Burn with a
little soot
Naphta 120 ° C -160°
C
Yellow Viscous Burn with a
more smoky
flame
Kerosene 160° C - 200°
C
Dark brown Very viscous Burn with a
very smoky
flame
12. Discussions:
1. Discuss the flammability of the fractions of
petroleum.
• The higher of the temperature, the
flammability will be decreases.
2.Discuss the relationship between the boiling
point of the fractions with the:
a) colour of the fractions
– The higher of the temperature, the colour of
the fraction wiil be darkness
13. Discussions:
b) viscosity of the fractions
• The higher of the temperature, the
viscosity of the fractions will be
increase
c) the amount of soot produced by
fractions
• The higher of the temperature, the
amount of soot produced by fractions
will be increases
14. Discussions:
3. Fraction X has a formula of C6H14. Predict its
colour , viscosity and the amount of soot
produced by X
Fraction
X
Temperature
range
80 ° C - 120° C
Colour Yellowish
Viscosity Slightly viscous
The amout of
soot
Burn with a
little soot
15. Discussions:
4. Write a balanced chemical equation to
represent the combustion of gasoline
(C8H18).
– C8H18 + 25/2 O2 8CO2 + 9H2O
5. The incomplete combustion of gasoline
results in emission of poisonous gasses
such as carbon monoxide and nitric oxide.
Write a balanced chemical equation to
represent the incomplete combustion of
gasoline (C8H18).
• C8H18 + 19/2 O2 + N2 8CO + 2NO + 9H2O
16. Discussions:
6. What is biodiesel?
• Biodiesel is a form of diesel fuel
manufactured from vegetable oils, animal
fats, or recycled restaurant greases. It is
safe, biodegradable, and produces less
air pollutants than petroleum-based
diesel. Biodiesel can be used in its pure
form (B100) or blended with petroleum
diesel. Common blends include B2 (2%
biodiesel), B5, and B20. B2 and B5 can be
used safely in most diesel engines.
17. Discussions:
7. What are the advantages of using biodiesel
compare to petroleum fuel.
• Advantages
• Domestically produced from non-petroluem,
renewable resources
• Can be used in most diesel engines, especially
newer ones
• Less air pollutants (other than nitrogen oxides)
and greenhouse gases
• Biodegradable
• Non-toxic
• Safer to handle
18. Conclusion
• Petroleum can be separated into its
fractions by fractional distillation.
• As the boiling point of the fraction
increases,
a) The darker the colour it is,
b) The more viscous it is, and
c) The more difficult it is burn with more
soot are produced.