liquid fuels properties and how to measure them

1. National Institute Of Technology
Thiruchirappalli
Department of mechanical engineering
A seminar presentation on
Liquid Fuel properties
Presented By
Name : Jatoth Mahesh
Roll no :211320009

2. Contents
Methods to estimate
1. Density
2. Viscosity
3. Flash and Fire point
4. Cloud point
5. Boiling point
6. Calorific value (higher and lower heating value)

3. 1. Density:
• Density of a liquid defined as the ratio of its mass to the volume.
• For example, if you had 1 gram of gasoline that measures 1.33 cm3 in volume, the
density would be 1/1.33 or about 0.75 g/cm3.
• The device which is used to calculate density practically is hydrometer.
• A hydrometer is a device that uses the principle of Archimedes to measure specific
gravity.
• Archimedes principle states that an object floating in a liquid will displace a quantity of
water that's equal to the weight of the object
𝑙𝑒𝑛𝑔𝑡ℎ 𝑖𝑚𝑚𝑒𝑟𝑠𝑒𝑑 𝑖𝑛 𝑤𝑎𝑡𝑒𝑟
𝑙𝑒𝑛𝑔ℎ𝑡 𝑖𝑚𝑚𝑒𝑟𝑠𝑒𝑑 𝑖𝑛 𝑓𝑢𝑒𝑙
=
𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑓𝑢𝑒𝑙
𝑑𝑒𝑛𝑠𝑖𝑡𝑦 𝑜𝑓 𝑡ℎ𝑒 𝑤𝑎𝑡𝑒𝑟

4. Construction of hydrometer:
• A hydrometer usually consists of a sealed hollow glass tube with a wider
bottom portion for buoyancy, a ballast such as lead or mercury for stability, and
a narrow stem with graduations for measuring

5. How to read hydrometer:
• Measure the temperature of the
liquid.
• Pour a sample into a clean
container.
• Insert the hydrometer into the
liquid.
• Spin the hydrometer gently.
• Wait till the hydrometer reaches
to equilibrium.
• Read the hydrometer scale at the
lowest point of the liquid's
surface.
• Understand the measurement

6. Density of fuels
fuel density(kg/m3)
Kerosene 775-840
Diesel 875-959
Gas oil 825-900
Gasoline 715-780

7. 2.viscosity:
• the viscosity of a fluid is a measure of its resistance to
deformation at a given rate.
• In petroleum technology this property widely used in design
calculation for transportation, combustion in burners and for
lubrication etc.
• Viscosity can be determined using U-tube viscometer
• U-tube viscometer also called as Ostwald viscometer
• Ostwald viscometer is used to determine viscosity of Newtonian
fluids only
• Ostwald viscometer is based on the poiseulle’s law.
• Other viscometers used to measure viscosity are
1. Saybolt viscometer
2. Redwood viscometer
3. Engler viscometer

9. • Viscosity of unknown liquid ƞL =
ƞ𝑤∗𝜌𝐿∗𝑡𝐿
𝜌𝑤∗𝑡𝑊
(cp)
• Ƞw = viscosity of distilled water (0.798cp)
• 𝜌w = density of distilled water (0.996kg/m3)
• 𝜌L = density of unknown liquid
• ȠL = viscosity of unknown liquid
• t = time taken for liquid or water to come from mark1 to mark 2
Liquids viscosity (poise)
Glycerine 14.9
Gasoline 0.006
kerosine 0.00164

10. Flash and fire point
Flash point: lowest temperature at which a liquid gives off enough
vapors to form an ignitable mixture with air.
Fire point: It is the minimum temperature at which the fuel oil vapors
continue to burn instead of flashing.
• For the same product the fire point is higher than the flash point
• Flash point measurement is used in shipping and safety regulations to
define flammable and combustible materials
• Flash point and fire point of lubricating oils, some crude oils and
residues are often determined by the open cup test and closed cup test
• In open cup test either Penskey-Martens cup or clevelend open cup is
used
• The open cup flash point is higher than the closed cup value

11. fuel Flash point
Gasoline -43℃
Diesel 52℃
Kerosine 38-72℃

12. Boiling point:
• The boiling point of substance is the temperature at which the vapor
pressure of a liquid is equals to the pressure surrounding the liquid
• A liquid in a vacuum has lower boiling point than that liquid at
atmospheric pressure
Cloud point :
• Cloud point is the temperature at which the lubricant becomes cloudy
or hazy when cooled
• It indicates the suitability of lubricant in cold conditions
• ASTM D 2500 standard is used to measure the cloud point of
petroleum fuel

14. Calorific value
• Calorific value is defined as the total amount of heat liberated from the
burning of unit mass of fuel in the presence of oxygen.
Higher calorific value :
• It is the amount of heat evolved when unit mass or unit volume of a
fuel is completely brunt in excess supply of oxygen and the biproducts
of combustion are allowed to cool at room temperature.
Lower calorific value:
• It is the amount of heat evolved when unit mass or unit volume of a
fuel is completely brunt in excess supply of oxygen and the biproducts
of combustion are allowed to escape in the atmosphere.
• LCV = HCV –LATENT HEAT OF VAPOURIZATION

15. Bomb calorimeter
• The Bomb Calorimeter is used to measure the cross calorific value of the
solid and liquid samples. It is a constant-volume type calorimeter that
measures the heat of a particular reaction or measures the calorific value
of the fuels.
• Bomb calorimeters are built in such a way that they can withstand
the large pressure produced within the calorimeter due to the
reaction or burning of fuel.
• The electrical energy is used as an ignition source for the burning
of testing fuels, and the heating filament is made up of tungsten
materials.
• In the bomb calorimeter, I g of the sample was taken in the crucible
and was electrically ignited to burn with the presence of pure
oxygen.
• During the combustion, heat was released and a rise in temperature
was measured

17. • Mass of the fuel sample taken = m (grams )
• Mass of the water taken in copper colorimeter = W (gram)
• Water equivalent of calorimeter = w (gram)
• Initial temperature of water = t1℃
• Final temperature of water = t2℃
• Heat liberated by the fuel = m*higher calorific value (HCV)
• Heat absorbed by the water = (W+w)*(t2-t1)
Therefore
Heat absorbed =heat liberated
HCV= (W+w)*(t2-t1)/m

18. Thank you…