Petroleum lab experiment 02 - octane number and cetane number

Petroleum lab

1. Koya University
Faculty of Engineering
Chemical Engineering Department – 2nd Stage

Petroleum & Gas Properties’ Laboratory
Experiment Name
Octane & Cetane Number
Experiment Date
28/10/2020
Submit Date
4/11/2020
Supervised by
Mr. Ahmed and Mr. Haval
Group B
Safeen Yaseen Jafar
Rayan Fuad Rashid
Rayan Younis Sabir
Sevar Yasin Ahmad
Sara Haider Qadir
Sema Mohammed Mawlood
Sarezh Hasan Othman

2. Table of Content
Subject Page
Aim of Experiment……………………………………………………………………… …. 1
Theory/Introduction...………...……………………………………………………… ….. 2-3
Methology of Tools….....…………………………………………………………… …… 4-5
Procedure…………………………………………………………………………………… …. 6-7
Calculation…………………………………………………………………………………… .. 8
Discussion………………………………………………………………………………… …… 9-17

3. 1

Aim of Experiment
✓ To determine Octane number of different gasoline samples .
✓ To measure cetane number of different diesel fuel samples .

4. 2

Theory/Introduction
Octane rating (octane number): A measure of performance of fuel for
internal combustion engines. Stated simply, a higher-octane rating corresponds to
more engine power and less knocking or other pre-ignition problems. Cetane
number (CN) is an empirical parameter associated with the ignition delay time of
diesel fuels, which is determined by means of standard tests based on the ASTM
D613 standard ignition delay is the time interval between the start of fuel injection
and the beginning of the oxidation reaction.
Also, Octane number shows the ability of a fuel to resist knock (pre-ignition
of the fuel) in the Gasoline Engine that needs high compression ratios. the Cetane
number is measures of ignition delay. Higher the cetane number of fuels the
shorter the ignition delay, the least time it takes to burn .
Definitions:
▪ Normally, the fuel/air mixture in an engine’s cylinder (s) burns and expands
in a controlled and linear fashion, spreading outwards from the spark at the
spark plug at the time of ignition. This is considered “normal” combustion.
▪ When the fuel/air mixture burns/explodes instantaneously, you get
detonation which creates shock pressure waves and thus an audible “knock”.







▪ Detonation, or “spark Knock” or “ping” is defined as an uncontrolled and
abrupt explosion of the fuel/air mixture in the engine cylinder(s) due to
excessive pressure and /or temperature.
▪ Octane number is the measure of the resistance of gasoline against
detonation or pre-ignition of the fuel in the engine.

5. 3

▪ It is measured relative to the mixture of iso-octane (2,2,4 trimethylpentane)
and n-heptane. Higher octane fuel has a greater resistance to autoignition
▪ under higher combustion pressure and heat.
▪ Pure n-Heptane has zero octane rating. It’s undesirable in gasoline, because
it burns explosively, causing engine knocking.
▪ Octane isomers (iso-octane; 2,2,4 trimethylpentane) which burn more slowly
and give better performance has octane number 100

6. 4

Tools

1. Gasoline











2. Diesel

7. 5

3. Octane Analyzer



























Right Alignment
Strip Left Alignment
Strip
LCD Digital
Display
KEYPAD
Sample Chamber
Sample
Power
Switch
Printer Paper
Compartment

8. 6

Procedure
1. Switch power to On. After 15 second countdown then “clear chamber &
Press measure “will appear.
2. Make sure there is no sample holder in the sample chamber. Cover the
chamber with the light shield.
3. Press the MEASURE key to standardize the instrument. After the “Reading”
takes place. “put in sample” will appear on the display.
4. Remove the light shield from the sample chamber .
5. Place the filled sample in the sample chamber, being careful to align the
alignment strips on the sample holder with the left alignment stripe on the
instrument.
6. Carefully, replace the light shield over the sample holder.
7. Press MEASURE after the “Reading” takes place, “remove and replace” will
be displayed.
8. Remove the sample holder and rotate it to align the stripe on the sample
holder with the right alignment stripe on the instrument.
9. Carefully, replace the light shield over the sample holder.
10. Press MEASURE after the “reading” takes place, “remove and replace” will
be displayed.
11. Remove the sample holder and carefully replace the light shield and press
MEASURE .
12. After the measurement is complete, repeat steps 3-11 to measure another
fuel sample.
To activate a product between Gasoline and Diesel
1. Turn instrument on
2. After countdown is complete, press MENU. Press the or button until the
display reads “Enable products “.
3. Press SELECET “enter product#” will be displayed on the LCD.
4. Press the number key that corresponds to the product to change the product
off or on.
Example:
Product 0 = Gasoline
a) press 0 “Gasoline Off” is displayed gasoline is deactivated

9. 7

b) Press 0 again “gasoline on” is displayed. Gasoline is activated.
5. Press CANCEL when complete

10. 8

Calculation
1. Octane Rate Test
Octane Rate – Test 1
RON 92
MON 82.2
Average 87.1

Octane Rate – Test 2
RON 89.9
MON 80.1
Average 84.6

2. Cetane Number Test

1. Octane Rate – Test 2
Result: 48.7
2. Octane Rate – Test 2
Result: 49.9

11. 9

Discussion - Safeen Yaseen Jafar
1. Which pure petroleum component (hydrocarbon) has the highest-
octane rating?
Isooctane or Pure 2,2,4-trimethylpentane is very resistant to knocking and is as
signed an octane number of 100. But the Para-Xylene has a highest-octane number
of 146.
Paraxylene, also known as PX or P-Xylene, is an aromatic hydrocarbon
compound, derived particularly from benzene. Paraxylene is a colorless, toxic,
sweet-smelling, and highly flammable chemical at room temperature. It is found
naturally in petroleum and coal tar. Paraxylene or P-Xylene is an isomer of xylene
compound, derived from benzene. Some of the other isomers of xylene include O-
xylene and M-xylene. Paraxylene finds its largest application in large-scale
manufacturing of terephthalic acid for polyester; also known as paraxylene. The
production process of paraxylene is one of the most complicated among all the
chemicals; simple crystallization of the xylene normally led to complex
purification process owing to the formation of eutectic mixtures. It is manufactured
by catalytic reforming of naphtha, a petroleum derivative, and separated in a series
of adsorption or crystallization, distillation, and reaction processes from ethyl
benzene, o-xylene, and m-xylene. The melting point of Paraxylene is highest
among other isomers of xylene.
2. What happens if it is added to gasoline?
Increasing the Isooctane in gasoline is one way to increase octane rating. so, if we
add it in gasoline the knock in the cars or vehicles is decrease.
3. What happens if kerosene is added to gasoline?
Kerosene is heavier than gasoline and has a much higher flash point and will
not burn or start as easily. The flash point of jet fuel (kerosene) is 100F for safety
not to ignite very easily and the flash point of gasoline is -50F. Because it is harder
to burn, the emissions will increase. The sulfur level of kerosene is also much
higher than the limits of gasoline and will poison the platinum in the catalytic
converter. Kerosene is a very low octane fuel so if you add it to gasoline you will
reduce the octane rating of gasoline and most likely it will be unusable in a car.
Kerosene is lot closer to diesel and if you add some to diesel it will most likely
work in a diesel car but it is not recommended because kerosene has a lower flash
point than diesel .

12. 10

4. What is the composition of gasoline and diesel?
Both gasoline and diesel fuel consist of hundreds of different hydrocarbon
molecules. In addition, several bio-origin components, such as ethanol in gasoline
blending, are common.
Gasoline Diesel
▪ Gasoline contains mainly
alkanes (paraffins), alkenes
(olefins), and aromatics.
▪ The hydrocarbons of gasoline
contain typically 4-12 carbon
atoms
▪ Diesel fuel consists mainly of
paraffins, aromatics and
naphthenes.
▪ Diesel fuel contains
hydrocarbons with
approximately 12–20 carbon
atoms

13. 11

Discussion – Rayan Fuad Rashid
Answers:
1. Premium (the highest-octane fuel–generally 91–94)

2. If your engine runs fine on regular, filling it with premium is unlikely to
boost acceleration or fuel economy by more than insignificant amounts. ...
The higher octane of premium gas won't make your car faster; in fact, the
opposite is possible because higher-octane fuel technically has less energy
than lower-octane fuel.

3. Since the octane number of kerosene is lower than that
of gasoline, kerosene- adulterated gasoline will cause knocking of the engine
This was noticed when the engine was run with the adulterated fuel in the
ratio of 50% kerosene and 50% gasoline.

14. 12

Discussion – Rayan Younis Sabir

1. which pure petroleum compound hydrocarbon has the highest octane
rate?
isooctane (2,2,4-trimethylpentane) and heptane. Isooctane is assigned an octane
number of 100. It is a highly branched compound that burns smoothly, with little
knock.

2. What happen if kerosene is added to gadoline?
Kerosene is heavier than gasoline and has a much higher flash point and will not
burn or start as easily. The flash point of jet fuel (kerosene) is 100F for safety not
to ignite very easily and the flash point of gasoline is -50F. Because it is harder to
burn, the emissions will increase. The sulfur level of kerosene is also much higher
than the limits of gasoline and will poison the platinum in the catalytic converter.

3. what happen if it is added to gasoline?
if it is addaed to gasoline the knock in the cars because increase octane rate.


4. what is composition of gasoline and diesel?
Gasoline is a petroleum-derived product comprising a mixture of liquid aliphatic
and aromatic hydrocarbons, ranging between C4 and C12 carbon atoms with the
boiling range of 30–225°C. It is predominantly a mixture of paraffins, naphthenes,
aromatics and olefins.
Petroleum-derived diesel is composed of about 75% saturated hydrocarbons
(primarily paraffins including n, iso, and cycloparaffins), and 25% aromatic
hydrocarbons (including naphthalenes and alkylbenzenes). The average chemical
formula for common diesel fuel is C12H24, ranging approximately from C10H20
to C15H28.

15. 13

Discussion – Sevar Yasin Ahmad
1/ Which pure petroleum component (hydrocarbon) has the highest octane
rating ?
Para-Xylene has a research octane number of 146.

2/ What happens if it is added to gasoline ?
Gasoline is one of the products derived from distilling and refining petroleum.
Compounds of organic lead were added to gasoline in the past to reduce knocking
in engines, but due to environmental concerns this is no longer common.

3/ What happens if kerosene is added to gasoline ?
Since the octane number of kerosene is lower than that of gasoline, kerosene-
adulterated gasoline will cause knocking of the engine . This was noticed when
the engine was run with the adulterated fuel in the ratio of 50% kerosene and
50% gasoline.

4/ what is the composition of diesel and gasoline ?
Diesel fuel consists mainly of paraffins, aromatics and naphthenes. The
hydrocarbons of gasoline contain typically 4-12 carbon atoms with boiling range
between 30 and 210 °C, whereas diesel fuel contains hydrocarbons with
approximately 12–20 carbon atoms and the boiling range is between 170 and 360
°C.

16. 14

Discussion – Sara Haider Qadir
1/ Which pure petroleum component (hydrocarbon) has the highest octane rating ?
Premium (the highest octane fuel–generally 91–94
2/ What happens if it is added to gasoline ?
The higher octane of premium gas won't make your car faster; in fact, the opposite
is possible because higher-octane fuel technically has less energy than lower-
octane fuel, . And if we add it in gasoline the knock in the cars or vehicles is
decrease.

3/ What happens if kerosene is added to gasoline ?
Since the octane number of kerosene is lower than that of gasoline, kerosene-
adulterated gasoline will cause knocking of the engine (Fonseca et al., 2007). This
was noticed when the engine was run with the adulterated fuel in the ratio of 50%
kerosene and 50% gasoline.

4/ What is the composition of diesel and gasoline ?
Petroleum-derived diesel is composed of about 75% saturated hydrocarbons
(primarily paraffins including n, iso, and cycloparaffins), and 25% aromatic
hydrocarbons (including naphthalenes and alkylbenzenes). The average chemical
formula for common diesel fuel is C12H24, ranging approximately from C10H20
to C15H28.

Gasoline is a petroleum-derived product comprising a mixture of liquid aliphatic
and aromatic hydrocarbons, ranging between C4 and C12 carbon atoms with the
boiling range of 30–225°C. It is predominantly a mixture of paraffins, naphthenes,
aromatics and olefins.

17. 15

Discussion – Sema Mohammed Mawlood
Q1// 2,2,4-trimethylpentane (commonly called iso-octane) and is used as one of
the standard values in the octane rating scale

Q2// while we add isooctane to gasoline octane number is increase and
Higher octane helps only if you have problems with your engine knocking , and
that's due to isooctane is anti knock.

Q3//because the octane number of kerosene is less than gasoline, kerosene-
adulterated gasoline will cause knocking of the engine , Another major issue is
that kerosene doesn’t vaporize easily and needs to be preheated in order to fully
mix effectivly with air for combustion.

Q4// diesel is composed of about 75% saturated hydrocarbons (primarily paraffins
including n, iso, and cycloparaffins), and 25% aromatic hydrocarbons (including
naphthalenes and alkylbenzenes). The average chemical formula for common
diesel fuel is C12H24, ranging approximately from C10H20 to C15H28.
And
The typical composition of gasoline hydrocarbons (% volume) is as follows: 4-8%
alkanes; 2-5%
alkenes; 25-40% isoalkanes; 3-7% cycloalkanes; l-4% cycloalkenes; and 20-50%
total aromatics
(0.5-2.5% benzene) .

18. 16

Discussion – Sarezh Hasan Othman
Q/1
Normal octan is a straight chain of carbon atoms Iso octans carbon atoms from
something like T and isooctane (2,2,4-trimethylpentane), which exhibits excellent
knock resistance, and is thus assigned a value of 100.
Q/2
standard measure of the performance of an engine or aviation gasoline. The higher
the octane number, the more compression the fuel can withstand before detonating.
In broad terms, fuels with a higher octane rating are used in high-performance
gasoline engines that require higher compression ratios
In contrast, fuels with lower octane numbers (but higher cetane numbers) are ideal
for diesel engines, because diesel engines (also referred to as compression-ignition
engines) do not compress the fuel, but rather compress only air and then inject fuel
into the air which was heated by compression.
Q/3
Kerosene is a very low octane fuel so if you add it to gasoline you will reduce the
octane rating of gasoline and most likely it will be unusable in a car
Kerosene is lot closer to diesel and if you add some to diesel it will most likely
work in a diesel car but it is not recomemnded because kerosene has a lower flash
point than diesel (it can be set on fire lot easier)
Since the octane number of kerosene is lower than that of gasoline, kerosene-
adulterated gasoline will cause knocking of the engine . This was noticed when the
engine was run with the adulterated fuel in the ratio of 50% kerosene and 50%
gasoline.
Q/4
What is the composition of gasolin and diesel?
Both gasoline and diesel fuel consist of hundreds of different hydrocarbon
molecules. In addition, several bio-origin components, such as ethanol in gasoline
blending, are common Gasoline contains mainly alkanes (paraffins), alkenes
(olefins), and aromatics. Diesel fuel consists mainly of paraffins, aromatics and
naphthenes. The hydrocarbons of gasoline contain typically 4-12 carbon atoms
with boiling range between 30 and 210 °C.

19. 17

The diesel fuel contains hydrocarbons with approximately 12–20 carbon atoms and
the boiling range is between 170 and 360 °C. Gasoline and diesel fuel contain
approximately 86 wt-% of carbon and 14 wt-% of hydrogen but the hydrogen to
carbon ratio changes somewhat depending on composition