This document discusses the thermal properties of petroleum fractions, including: - Specific heat depends on temperature and density, with lighter fractions having higher specific heat. - Heat of combustion decreases from paraffins to aromatics and is related to hydrogen content. - Latent heat of vaporization varies with temperature, molecular weight, and other parameters and can be calculated using a provided equation. - Latent heat of fusion is approximately 50% of latent heat of vaporization and is around 167-170 kJ/kg for waxy distillates and waxes. - Thermal expansion causes petroleum fractions to change in shape, area, and volume with temperature changes.

1. THERMAL PROPERTIES
OF PETROLEUM
FRACTIONS
G.Dharani Kumar
Reg no . 160080011
1st semester, 3rd year, Petroleum Engineering
KLEF (Deemed to be University)
Green Fields, Vaddeswaram, Guntur, Andhra
Pradesh, India Pincode - 522502
E-mail: dharaninavya57@gmail.com
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2. Contents
1 Specific heat
2 Heat of Combustion
3 Latent heat of Vapourisation
4 Latent heat of Fusion
5 Thermal expansion
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3. I. Specific Heat
Specific heat of petroleum fraction lies in the range
of 0.3 to 0.85 and it depends upon temperature and
gravity.
Lighter fractions have higher specific heat values.
With increasing density the specific heat decreases.
Bureau formula : -
Sp . Heat = 1/ῤ (0.4024 + 0.00081*t)
t = temp, ċ
ῤ = sp.gravity at 15.6/15.6 ċ
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4. II. Heat of Combustion
Hydrogen is distinct for its heat of combustion
i,e.183.6 * 10^3 kj/kg.
Obviously higher hydrogen fractions will be have
more heat of combustion.
Thus in the order of paraffins to aromatics, the heat of
combustion decreases.
Sherman – kropff relationship :
Heating value kj / kg = 43,434+93.2(API-10)
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5. III. Latent Heat of Vapourisation
Latent heat varies with the temperature.
It is related to molecular weight,API, molal
average point.
Above parameters are sufficient to give latent
heat of vapourisation.
ΔΗv = ΔΗ t2(T1 - T2/ Tc – T2)^n
n varies from 0.38 to 0.466
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6. IV. Latent heat of Fusion
The enthalpy of fusion of a substance, also
known as (latent) heat of fusion
The heat of fusion is approximately 50% of
latent heat of vaporisation.
For waxy distillates and waxes, the average
latent heat of fusion may be taken as 167 to 170
kj per kg.
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7. V. Thermal Expansion
Thermal expansion is the tendency of matter to
change in shape, area, and volume in response to
a change in temperature.
Like all the fluids, petroleum fractions also
suffer in loss of density due to thermal expansion.
Coefficient of expansion is very much required
to find out the volume of the container, which is
exposed to frequent changes of temperature.
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8. V. Viscosity & Viscosity Index
Viscosity is an important property for all
lubrication oils.
Lubrication assists in removing the frictional
forces between two moving bodies.
In all refinery operations instead of absolute
viscosity kinematic viscosity is used.
Kinematic Viscosity = (Absoluteviscosity / Sp.g)
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9. Viscosity Index(V I)
Here V I is represented in the Figure.
Two liquids L & H.
L having a V I zero.
H having a V I 100.
By all these samples we will get the value of U.
V I = (L - U / L – H) * 100
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11. THANK YOU
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