Characteristics of common petroleum fuels: petrol, diesel, kerosene, LPG, CNG, Butane, Propane and the main petroleum additives
Keep in mind that no fuel is a pure compound. They are all (with some exceptions) a mixture of miscible compounds with complementary properties. Characteristics definitions are on fuel definitions
Gasoline (heptane)
Chemical formula:
C7 H16 (approached to 4 7 carbon atoms)
Octane number:
RON 95 / 98
distillation characteristics:
Range of around 30 to 210 ° C
Starting point 27 ° C
Evaporating temperature:
between room temperature and 215 ° C
Density:
0,755 (approached to 0,72 0,78 15 to ° C)
Advantages:
Reduction compared to gasoline or diesel engine:
- 30 to 65% of NOx and HC
- 40 to 75% of CO
- 15% of CO2
No particles
Higher octane number allowing a reduction in consumption on optimized engines (rarely the case)
It is a valued refining or oil extraction “waste”.
CNG (Natural Gas for Vehicles, methane)
Chemical formula:
CH4 (essentially methane, 80% to 97%)
Octane RON:
120
Ignition temperature:
650°C
Aspect:
naturally colorless and odorless (odor it is added by chemical addition)
Disadvantage:
GVN is stored in the gaseous state. It is compressed under a pressure of 200 bars when filling the vehicle tank.
This filling can last from 1 hour to 7 hours depending on the equipment used.
Advantages:
50% less CO and HC, no sulfur or particles.
High octane number allowing an improvement in engine efficiency.
Stocks are higher than those of crude oil.
Butane
Density: 2,703
Calorific power:
45 600 kJ / kg
Chemical formula:
C4H10
Sulfur content:
0.02% maximum
Boiling temperature:
-5 ° C
liquefaction pressure 15 ° C:
1,5 bar
Auto-ignition temperature:
510 ° C
Octane:
95
approximate composition of commercial butane:
N-butane & isobutane *:
94,8%
Propane:
4,2%
butene:
1%
methyl-propane (formerly iso butane)
Propane
Density:
2,008
Calorific power:
46 300 kJ / kg
Chemical formula:
C3H8
Sulfur content:
0.02% maximum
Boiling temperature:
-42 ° C
liquefaction pressure 15 ° C:
7,5 bar
Calorific power:
1 kg: 12,78 13,8 kW kW
M1 3: 23,9 25,9 kW kW
Auto-ignition temperature:
490 ° C
Octane:
100
approximate composition of commercial propane
Propane:
94,9%
N butane & isobutane *:
2,39%
Ethene & Ethane:
2%
Propene (C3H6):
0,89%
butene:
0.039%
methyl-propane (formerly iso butane)
Petroleum additives
2 main classes of additives for gasoline:
- octane number improvers
- detergents (keeping the intake circuit in a perfect state of cleanliness at all times limits the adjustments that may be caused by soiling)
Tetraethyl lead:
(used to increase the octane rate)
chemical formula:
Pb (C2H5) 4
origin:
additive providing 4 to 5 octane point to gasoline
associated pollutant:
The lead:
(used to increase the octane rate, and because of its properties lubricated the valve stems and protected the seats by its deposits)
- Was abolished on January 1, 2000 due to pollution.
methyl:
(used to increase the octane rate)
used for unleaded gasoline
tert-butyl ether:
(used to increase the octane rate)
used for unleaded gasoline