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NSIKAK -JEUEL JOHN ITUH ~ ,
The Effect of Palm Kernel Oil on the Heat of Combustion of Diesel
Bachelor Thesis Pure Chemistry 1999
TH£ £ff£CT Of PALM 1{£RN£l Oll ON TH£
H£A T Of COMBVSTlON Of D1£S£l
A RESEARCH PROJECT
ITUH, NSIRL\R )OHN REG.NO. 95/UGO 9109
TO
THE DEPARTMENT OF CHEMISTRY/BIOCHEMISTRY FACULTY OF NATURAL AND APPLIED SCIENCE
UNIVERSITY OF UYO , UYO AKWA IBOM STATE
IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE AWARD OF A
BACHELOR OF SCIENCE (B.Sc.) DEGREE IN PURE CHEMISTRY.
DECEMBER, 1999
DEDICATION
This project is dedicated to God the Father, God the Son and God the
Holy Ghost.
And to the man who made my dreams come true John Sam Ituh - In
comfortable memory.
It is the uncompromising principle that guided life and the lessons you
taught that still guide my everyday thought.
To God be the Glory.
-'
CERTIFICATION
This project entitled The Effect of Palm Kernel Oil on the Heat of
Combustion of Diesel is the original work carried out by
ITUH, NSIKAK JOHN and is acceptable in partial fulfillment of the,
requirements for the award of the B.Sc. degree in Pure Chemistry of the
University of Uyo and is approved for its contribution to knowledge and
literary presentation.
Name of Student: ITUH, NSIKAK JOHN
Signature: ··~····· Supervisor: Mr. I. A. Akpan
Signature: ..... ~~---~~ Head of Department: Dr. E. I. Udoessien
Signature: ~ .... .. .... ....... \ ;;?. ·· ·· · · ·· ···· · ·····§··]3······~ ..
External Exa~ ~
Date: _.Q~ _:Q5~J.0..QO
Date: ... .. <5.= .. £=~~
Date: J~/. .. ?.7 .~
ACKNOWLEDGEMENT I acknowledge with deep sense of gratitude the invaluable contributions
made by several persons towards the successful completion of this project. I would like to express my sincere gratitude to my mother "J.II.;r~ Qrelce. Ake.Clbrui John for laying a solid educational foundation
for me. My unreserved gratitude goes to my elder sister Mrs Dara Udoh for
all the financial support and the rest of my sisters, Dr. Vidoria Eyo, Uduak John, Je=:>ir7id John Eno John. Also very grateful to auntie Martina, Agnes,Tessy,Paufina,Veronica,Rita and Unde Joe Uwakrr_ifon for all the financial and moral support.
I am indebted specially to my supervisor M r • I • A • A k pan who at various stages rendered his Immense and invaluable assistance towards the making of this project to reality.
I would like to thank Mr. Ndah and Mr. Umoh who through their technical assistance made this project a success.
My heartfelt appreciation to the following colleagues for their assistance; ln1 Akpan, lnemes1t Uwah ,Lanre Sharafa Bukola Ab1ona, Nkem Udekwu, Ubong Uwatt, Gabnel Otu, Eme Hogan,Ekaette Edemeka, Ephra1m Udoh, Ndueseme Jonah,Samuel Jones, Phobe Eyo, T1-AbasJ !fut, Ubong Uwah, Bassey Ba~~fYn Breakthrough Dav1d, ldonges1t In~'~ ,Glory Okegbe, Uwem ~ whom I cherish so much for the a¥sistahce and encouragement I received from them. Also Udo~-i..a Fe.U..x Iniobong Udo6-i..a, Eme.m Udo6-i..a, such a wonderful family. Much love to '}?etu[ ~~~char ('Pen.), '}?rethe ~~~char, Cel(eb ~~~char,friends whom I cannot replace. Finally I thank God for His grace which has made me to realize my dreams.
ITUH, NSikAk JOHN 9S/UQOgto, 1):E1rf.Of fJU'JU. OH:E~I~l' UNI\)~Sin' Of U)JO U)'O.
_ .....
TABLE OF CONTENTS
Title Page Dedication Certification Acknowledgement Table of Contents Abstract List of Figures List of Appendices ..
CHAPTER ONE INTRODUCTION AND LITERATURE REVIEW 1.1 Introduction 1.1 Literature Review 1.1.1 Source of Diesel 1.1.2 Properties of Diesel .. 1.1.2.1 Physical Properties of Diesel 1.1.2.2 Chemical Properties of Diesel 1.2.2.2.3 Combustion of Diesel 1.2.3 Additive and Combustion 1.2.4 Uses of Diesel 1.2.5 Palm Kernel Oil (PKO) 1.2.5.1 Properties of Palm Kernel Oil 1.2.5.1.1 Chemical Properties .. 1.2.5.1.2 Physical properties .. 1.2.5.2 Uses of Palm Kernel Oil 1.2.6 Aims and Objectives of the Study
CHAPTER TWO EXPERIMENTAL
..
11
lll
IV
V
Vll
Vlll
X
1 2 3 3 4 5 5 6 7 7 8 8 8 8 9
2.1 Material Preparation .. 10 2.2 Determination of Heat of Combustion ofPure Diesel 10 2.3 Determination of Heat of Combustion of Pure Diesel
with the addition of Palm Kernel Oil at different concentrations. 11
CHAPTER THREE RESULTS 3.1 Presentation of Data for Combustion rate of diesel
3.2
3.3
3.4
+ PKO at various concentrations Presentation of Data for Heat of Combustion of diesel + PKO at various concentrations Presentation of Data for the variation of Weight with time During the combustion of pure diesel for 1 hour .. Presentation of Data for the variation of Weight with time During the combustion of pure diesel + PKO for 1 hour At various concentrations
CHAPTER FOUR DISCUSSION
13
13
14
14
4.1 Heat of Combustion ofPure Diesel 18 4.1.1. The Effect ofPKO on the Combustion rate of Diesel 18 4.1.2. The Effect ofPKO on the Heat of Combustion of Diesel .. 19 4.2 Application of the Principles of Chemical Kinetics
to the present result 22 4.3 Mechanism of the action Palm Kernel Oil on Diesel 26
CHAPTER FIVE CONCLUSION AND SUGGESTIONS FOR FURTHER INVESTIGATION 5.1 Conclusion 5.2 Suggestions for further investigation
References
Appendices
29 30
\ I
ABSTRACT
The Combustion of Diesel and the effects of Palm Kernel Oil on the
Combustion rate and on the Heat of Combustion have been investigated. The
Combustion rate decreases in the presence of the additive and tends to reach
a minimum at 4cm3 of the additive in 15cm3 of the Diesel sample.
The Combustion rate for Pure Diesel sample was found to be
2.85 x 104 cm3 sec"1 while lower values of 1.93 x 104 cm3 sec·1 and
1.60 x 104 cm3 sec·1 were obtained when the additive (lcm3 and 4cm3)
respectively were added to the fixed volume of Diesel (15cm3) . The
lowering of the Combustion rate suggest that PKO has some anti knock
properties.
A gradual increase in the Combustion rate has been observed when
the volume of the additive was increased above 4cm3 in the same volume of
the Diesel.
The Heat of Combustion value for Pure Diesel sample as
experimentally determined was -1500 KJmol"1. Higher values of
- 1590KJmol"1 and - 1842KJ mol"1 was obtained with the additive
concentration of 1 cm3 and 4cm3 respectively mixed with 15cm3 of the Diesel
sample. The Heat of Combustion values show a remarkable increase with
increased concentration of the additive.
The analysis of the weight loss with time for the combustion of Diesel
and a plot of the kinetic data reveals a first order mechanism. Lower values
of rate constant were recorded with the presence of the additive against the
high value of the Pure Diesel sample. The lowering of the rate constants
agrees well with the corresponding longer half-life value recorded upon the
introduction of the additive.
Infrared spectrum reveals an elimination of the OH-group and an
introduction of a -CO group by the additive which probably amounts to a
substitution of a carbon atom for a hydrogen atom.
LIST OF TABLES
3.1 Presentation of data for Combustion rate of diesel + PKO at Various Concentration. 13
3.2 Presentation of data for Heat of Combustion of Diesel + PKO at various concentrations. 13
3.3 Variation of weight with time during the Combustion of Pure Diesel. 14
3.4 Variation of weight with time during the Combustion of Diesel in the presence ofPalm Kernel Oil (1cm3
) as additive. 14
3.5 Variation of weight with time during the Combustion of Diesel in the presence of Palm Kernel Oil (2cm3
) as additive. 14
3.6 Variation of weight with time during the combustion of Diesel in the presence of Palm Kernel Oil (3cm3
) as additive. 15
3.7 Variation of weight with time during the Combustion of Diesel in the presence of Palm Kernel Oil ( 4cm3
) as additive. 15
3.8 Variation of weight with time during the Combustion of Diesel in the presence of Palm Kernel Oi l (5cm3
) as additive. 15
3.9 Variation of weight with time during the Combustion of Diesel in the presence of Palm Kernel Oil (6cm3
) as additive. 16
3.10 Variation ofweight with time during the Combustion of Diesel in the presence of Palm Kernel Oil (7cm3
) as additive. 16
3.11 Variation of weight with time during the Combustion of Diesel in the presence of Palm Kernel Oil (8cm3
) as additive. 16
3. 12 Variation of weight with time during the Combustion of Diesel in the presence of Palm Kernel Oil (9cm3
) as additive. 17
3.13 Variation of weight with time during the Combustion of Diesel in the presence of Palm Kernel Oil (1 Ocm3
) as additive. 17
4.1 Rate Constants and Half life for the Combustion of Pure Diesel and in the presence of various concentrations of Palm Kernel Oil as additive. 25
Fig. 2. 1
Fig. 3. 1
Fig. 3.2
Fig. 3.3
Fig. 3.4
Fig. 4.1
F ig. 4.2
LIST OF FIGURES
The set-up for the determination of Heat of Combustion. 12
Combustion rate (cm3/sec) against Volume of PKO (cm3) 20
Heat of Combustion (K Jmor 1) against Weight ofPKO (cm3
) 21
Log (Wi- 11 W) against Time (mins) . 23
11 W against Time (m ins) 24
Infrared spectrum of Pure Diesel 27
Infrared spectrum of Pure Diesel with PKO as additive. 28
...
LIST OF APPENDICES
Appendix 1. Determination of Heat of Combustion and Combustion Rate of
Pure Diesel 33
Appendix 2 Determination of Heat of Combustion and Combustion rate of
Pure Diesel in the presence of various concentrations of the
additive PKO. 35
Appendix 3 Determination of rate constants and half life for the
Combustion Pure Diesel and in the presence of vanous
concentrations of the additive PKO. 37
CHAPTER ONE
INTRODUCTION AND LITERATURE REVIEW
1.1 INTRODUCTION
Combustion is the branch of science and technology that deals with
the liberation and use of energy evolved during the reaction of chemical
species (Hampel and Hawley, 1973).
The burning includes any substance in gaseous, liquid or solid form.
In its broad definitions, combustion includes fast exhothermic chemical
reactions, generally in the gas phase but not excluding reaction of solid
carbon with a gaseous oxidant. Flames represent combustion reactions that
can propagate through space at subsonic velocity and are accompanied by the
emission of light. The flame is a result of complex interactions of physical &
chemical processes whose quantitative description must draw on a wide
range of discipline, such as chemistry, thermodynamics etc .
In the course of chemical reaction energy is released in the form of
heat and atoms and free radicals all highly reactive intermediates of
combustion reactions are generated (Beer, 1997).
The process of combustion, which is the burning of a substance in
oxygen is always accompanied by the evolution of heat. The amount of heat
evolved when one mole of a substance is burned completely in oxygen is
known as the heat of combustion. The heat of combustion is an important
quantity, since the combustion of fuels form the main source of energy used
for industrial domestic purposes. Besides these the energy used by the living
body is also obtained from the biological combustion of food.
However, for practical purposes, the relative effectiveness of a fuel is
expressed more often in terms of its calorific value which is the amount of
heat evolved per kilogram of substance. (Ababio, 1998).
Combustion is the major mode of fuel utilization in domestic and
industrial heating, in production of steam for industrial processes and for
electric power generation, in waste incineration and for propulsion in internal
combustion engines, gas turbines and rocket engines.
1.2 LITERATURE REVIEW
1.2.1 SOURCE OF DIESEL
1.2.1.1. Simple Distillation Of Crude Oil
Distillation is the primary method used to refined petroleum. The tall
metal towers that characterize petroleum refineries are disti llation or
fractionating towers . When heated crude oil is fed into the tower, the higher
oil pot1ions, or fractions, vaporise, loosing temperature as they rise, hence
they condense into liquids, which flow downward into the higher
temperatures and are vaporized.
These processes continue until various fractions have achieved the
appropriate degrees of purity. The lighter fractions like butane, gasoline and
2
kerosene are tapped off from the top; heavier fractions like fuel and diesel
oils are taken from below (Speight, 1997).
1.2.2.
1.2.2.1.
PROPERTIES OF DIESEL
Physical Properties
I. Ignition quality/Cetane Number:
This factor influences ease of starting, duration of white smoking after
startup, derivability before warm up, and intensity of diesel knock at idle.
Standard cetane number ranges between 30-60 and flash point at 55°C. (It is
worthy of note here that flash point is the temperature at which vapour from
the oil may be ignited).
2. Viscosity:
This influences the spray pattern when the fuel is injected into the
cylinder. Minimum viscosity limits are usually imposed to prevent the fuel
from causing wear in the fuel injection pump.
3. Storage Stability:
In storage diesel is usually attacked by atmospheric oxygen which can
cause deposition of vanish. Antioxidants and dispersants are added to
prevent such problems while copper metal deactivators reduce the catalytic
effect screens and other parts.
3
1.2.2.2. Chemical Properties
1. Volatility:
The volatility has little influence on its engine performance except as
it affects exhaust smoking tendencies.
2. Heating Value:
Fleet operators, railroad and shipping companies are concerned about
fuel economy. The aim is to use fuel with the greatest heating value.
The factors that affect heating value are density and mid boiling point.
3. Water content:
Diesel contains small amount of water (about 0.5 vol.% water). The
amount that a fuel can hold is controlled by hydrocarbon type,
distribution and bulk temperature. Excessive water in a fuel system
should be drained regularly to prevent bacterial contamination and the
pumping of water into fuel distribution system.
4. Sulfur Content:
Depending on the crude source, diesel contains various amounts of
sulfur compounds, which yield corrosive sulfur oxides on combustion.
These can cause high rate of engine wear and rapid depletion of
engine oil additives. Engine manufacturers often relate oil change
intervals to the sulfur content.
(http./www.lubrizol.com/referencelibrary/readyreference/8-fuels/feltext.htm,)
pp.4-7, via the Internet, 1999
4
1.2.2.2.1. Combustion of Diesel
The basic use of diesel is as a source of energy (i.e as fuel). This is
because the combustion process is exothermic. In plentiful supply of
oxygen, methane or butane (as it were being a functional group in diesel is
being used here for this illustration) burns completely a flame to give carbon
(IV) oxide and water.
CH4 + 202
C4HIO+ 13/2 02
--! .... C02 + H20
--!.... 4C02 + 5H20
Other alkanes react in the same way. Using one hydrocarbon component of
petrol as an example.
If sufficient oxygen is present for complete combustion, poisonous carbon
(II) Oxide (CO) is produced instead of carbon (IV) oxide C02. The situation
exists in the cylinders of diesel engines when incomplete combustion occurs,
the exhaust flames contains poisonous carbon (II) oxide and sometimes even
carbon. This is why it is dangerous to run a car engine inside a garage where
free flow of air is not possible (Ababio, 1998).
1.2.3. ADDITIVES AND COMBUSTION RATE
Diesel with high octane rating is very expensive. Hence to reduce the
cost, without lowering the quantity of the fuel, additives were developed by
the petroleum industry.
5
One of such additives is tetraethyllead (IV) TEL, Pb(C2H5) 4, which reduces
the octane rating by slowing down the combustion rate of the hydrocarbon.
With this, the automobile is able to run smoothly without "knocking". The
additive is therefore called an anti-knock. Other additives used in diesel
include amyl nitrate (C5H1 1N03) or hexyl nitrate, which improves the low
cetane number.
It must be noted that the addition of TEL into diesel to improve its
performance inevitably introduces Lead as a pollutant into our environment,
which is a serious health hazard.
The octane rating of diesel is a measure of its performance
(combustion rate) in an internal combustion engine. Diesel of low quality,
containing large proportion of straight-chain alkanes bums rapidly and
unevenly, disturbs the up and down movement of the piston in the engine.
This causes a strange sound, usually referred to as "engine knocking".
On the other hand, a branched chain alkane burns smoothly and does
not disturb the piston action. An arbitrary scale has been devised which
ranges from 0 for hexadecane (straight - chain alkane) to 100 for
heptamethylnonane. It is independent on the ratio of branched - chain alkane
to straight - chain hydrocarbon in diesel. (Ababio, 1998).
6
,,
1.2.4 USES OF DIESEL
Diesel contains hydrocarbons with carbon atoms ranging from 14 to
18 a molecule. It is basically used in internal combustion engines of the
diesel type these include, railroad engines, electric power generation engine,
tractor engine, marine engine and other heavy-duty engines. (Speight, 1997).
1.2.5 PALM KERNEL OIL
Palm kernel oil is extracted from the center nuts of the same fruit
cluster, which yields palm oil. It is classified under fats & oils (food), it is
also named under lauric acid. It is a triglyceride with three fatty acid groups
randomly esterified with glycerol. (Ryer, 1969)
Triglyceride contains approximately 95% fatty acids and 5% glycerol
combined as esters. They have the following structural formula.
H I
H - C -OCR I
H -c -OCR' I
H - c -ocR'' I H
Hence, the physical and chemical properties are determined largely by the
properties of its component fatty acids (Norris, 1969).
7
1.2.5.1
1.2.5.1.1.
PROPERTIES OF PALM KERNEL OIL
Chemical Properties
1. It consist of antioxidants in minor proportions (0.05 - 0.20%) which
serve to inhibit atmospheric oxidation.
2 . It has some proportion of vitamin A
3. A relative constituent sterol which are colourless, odourless and
generally inert and forms most of the 0. 5 - 0.15 unsaponifiable
material content of fat and oils (N orris, 1969).
1.2.5.1.2 Physical Properties
1. It is solid at room temperatures
2. It is insoluble in water and soluble m orgamc solvents such as
petroleum, hydrocarbons, ether and chloroform (Weisis, 1997)
3. It melts sharply at relative low temperature of 29°C
4. Low in non-glyceride constituents
5. It has relative low viscosity
6. It is bright coloured (Norris, 1969).
1.2.5.2 Uses Of Palm Kernel Oil
1. Palm Kernel Oil is suitable for soap making because of its straight
chain carbon atoms ofC 17•
2. Also it can be used for surface active materials, lubricating and
plasticising (Ryer, 1969)
8
3. Industrially, it is a source of energy and the most common form of
food energy.
4. It helps in making prepared food more palatable by improving the
texture and providing a more palatable flavor. (Weisis, 1997).
1.2.6 AIMS AND OBJECTIVES OF THE STUDY
The principal aim of this study is to investigate the methods to
improve the combustion rate of diesel. Also to investigate substances
suitable that can be added in regulated quantity to reduce the combustion rate
of diesel.
Due to chain branching of long chain carbon atoms in diesel, it has
high level knocking tendency, but through this study intense investigation is
being made on how this additive can offer maximum efficiency to
combustion thereby reducing the knocking tendency of internal combustion
engines (diesel engines), thereby making diesel a better fuel for use since the
use of diesel engine results in considerable fuel economy.
9
CHAPTER TWO
EXPERIMENTAL
2.1 MATERIAL PREPARATION
The following materials and apparatus were used.
1. Retort stand
2. Clamp
3. Tile
4. Thermometer
5. Stop watch
6. Stirrer
7. 250 ml beaker
8. Spirit lamp
9. Diesel (which was acquired form a service station within the locality)
10. Palm Kernel Oil (was obtained from the local market)
The above materials except otherwise stated, were procured from the
stone ofthe Chemistry Department laboratory store, University ofUyo.
2.2. DETERMINATION OF HEAT OF COMBUSTION OF PURE DIESEL
METHOD:
This experiment was carried out in a draught-free area. The diesel
was burned in a spirit lamp, the wick of the lamp is inserted through a glass
tube held in he cork of the lamp so that it dips in the diesel contained in the
10
bottle. The lamp was then weighted with the diesel before the start of the
experiment and the mass was recorded. A known mass of water (1 OOg) was
then put in the beaker and clamped above the lamp.
With the use of the thermometer the initial temperature of the water
was recorded. The wick of the lamp was then lighted and was placed directly
under the beaker. The water is then stined frequently using the stirrer. As
the temperature of the water increased by about 25°C, the final temperature
was recorded, also the flame was put off and the lamp with the diesel was
reweighed to determine the loss in weight.
2.3 DETERMINATION OF HEAT OF COMBUSTION OF DIESEL WITH ADDITION OF PALM KERNEL OIL AT VARIOUS CONCENTRATIONS.
METHOD:
This experiment was carried out in a draught free area. Diesel
(15cm3) was put into the spirit lamp after which palm kernel oil (lcm3
) was
added. The wick of the lamp is then inserted through a glass tube held in the
cork, so that it dipped into the mixture (Diesel + PKO) contained in the
bottle. The Lamp was then weighed with the mixture before the start of the
experiment and the mass recorded. A known mass of water (lOOg) was then
put in the beaker and clamped above the lamp.
With the use of the thermometer the initial temperature was recorded.
The wick of the lamp is then lighted and put directly under the beaker to
11
allow the flame heat up the water in the beaker, the water was then stirred
frequently using the stirrer. When the temperature of the water increased by
about 25°C the final temperature was recorded, then the flame was put off
and the lamp with the mixture was reweighed to determine the loss in weight.
This process was repeated for a range of concentrations of PKO between
1 cm3
to 1 Ocm3
while the volume of diesel remained constant.
Fig 2.1
The set-up for the determination of heat of combustion
-·- · - - thP.rrnometer
- -- v.r.ate:
0] flame
j
glas-s tub.,. r .. J
spi · it -fan1p (
fi ·ethanol u
c
-----t l
vvick 2~
12
CHAPTER THREE
RESULTS
The results obtained are hereby presented in tables 3.1 to 3.13 Table 3.1
Presentation of data for combustion rate of diesel + PKO at various concentrations Volume of Diesel = 15cm3
Vol.ofPKO' Mass of Diesel Mass of diesel In itial Fina l Temp. T ime Combustion Added +PKO before +PKO nftcr Tcmp.(K) Temp.(K) Rise DT(K) (Secs) Ra te (cm3/Sc) (cm3
) burning burning
O.cm3 149.2 14 147.6 14 302 327 25 560 2.85 X 10-4
l cm3 148.71 9 147.207 30 1 326 25 837 1.93 x 1 o-4
2cm3 149.690 148.290 30 1 326 25 871 1.81 X 10-4
3cm3 150.6 19 149.3 19 302 327 25 902 1.71 X 10-4
4cm3 151.70 1 150.500 303 328 25 937 1.60 X 10-4
5cm3 152.542 151.342 30 1 326 25 973 1.61 X 10-4
6cm3 153.51 9 152.3 19 30 1 326 25 1000 1.64x 10-4
7cm3 154.628 153.428 302 327 25 1020 1.66 X 10-4
8cm3 155.520 154.3 14 301 326 25 1043 1.69 X 10-4
9cm3 156.71 9 155.50 1 303 326 25 1080 1.69 X 10-4
10cm3 157.5 15 156.302 30 1 32 25 1112 1.70 X 10-4
Table 3.2 Presentation of data for Heat of combustion of diesel + PKO at va rious concentrations Vol. of diesel = 15m3
VoLofPK01 Mass of Diesel Mass of Initial F inal Temp. Time Combustion Added + PKO before diesel +PKO Temp Temp. Rise (Sees) Rate
_{_cm3) burning after burn ing (K) (K) DT(K) (cm3/Se)
O.cm3 149.2 14 147.61 4 302 327 25 560 - 1500
lcm3 148.2 19 147.207 30 1 326 25 837 - 1590
2cm3 149.690 148.290 301 326 25 871 - 172 1
3cm3 150.6 19 149.3 19 302 327 25 902 -1 842
4cm3 151.70 1 150.500 303 328 25 937 -1 98 1
5cm3 152.542 151.342 301 326 25 973 - 198 1
6cm3 153.5 19 152.3 19 30 1 326 25 1000 - 198 1
7cm3 154.628 153 .428 302 327 25 1020 - 198 1
8cm3 155.520 154.3 14 301 326 25 1043 -1981
9cm3 156.7 19 155.50 1 303 328 25 1080 - 1981
10cm3 157.5 15 156.302 30 1 326 25 1112 - 1981
13
Table 3.3 Variation of weight with time during the combustion of pure diesel for 1 hour Volume of diesel = 15cm3
Time Initial Weight Final Weight Weight Loss Log (m ins) Wi(g) wf(g) tlw == wi-wf(g) (wi - tl w)g IOmins 146.826 146.039 0.787 2.164
20 mins 146.826 145.349 1.477 2.162
30 mins 146.826 144.443 2.383 2.159
40 mins 146.826 I 43.374 3.452 2. 156
50 mins 146.826 142.252 4.574 2. 153
60 mins 146.826 14 1.1 48 5.678 2.149
Table 3.4 Table Variation of weight with time during the Combustion of diesel in the presence ofPKO (lcm3
) as additive for 1 hour Vol. of diesel = 15cm3
Time Initial Weight Final Weight Weight Loss Log (wi-tlw)g (m ins) wi(g) wf(g) tlw ==wi-wf(g) IOmins 146.933 144.734 2.199 2.160
20 mins 146.933 142.300 4.633 2. 153
30 mins 146.933 139.800 7.133 2. 145
40 mins 146.933 137.400 9.533 2.137
50 mins 146.933 135.393 I 1.540 2.131
60 mins 146.933 133.400 13 .533 2.125
Table 3.5 Variation of weight with time during the Combustion of diesel in the presence of PKO (2cm3
) as additive for I hour. Vol. of diesel = 15cm3
Time Initial F ina l Weight Weight Loss Log (mins) Weight wi(g) wf(g) tlw== wi-wf(g) (wi- tlw)g IOmins 148.000 145.860 2.140 2.163
20 mins 148.000 143.683 4.3 17 2. 157
30 mins 148.000 141.420 6.580 2.150
40 mins 148.000 139.244 8.756 2.143
50 mins 148.000 137.165 9.835 2.140
60 mins 148.000 135.361 12.639 2. 13 I
14
Table 3.6 Variation of weight with time during the combustion of PKO (3cm3
) as additive for 1 hour Vol.of diesel = 15cm3
•
Time Initial Final Weight Weight Loss Log (mins) Weight wi(g) wf(g) lnv= wi-wf(g) (wi-~w_}g
IOmins 148.600 146.942 1.658 2.167
20 mins 148.600 145.361 3.239 2.162
30 mins 148.600 143.673 4.927 2. 157
40 mins 148.600 142.085 6.515 2 .152
50 mins 148.600 140.480 8.120 2.147
60 mins 148.600 138.952 9.648 2. 142
Table 3.7 Variation of weight with time during the combustion of PKO (3cm3
) as additive for 1 hour Vol.of diesel = 15cm3
•
Time Initial Weight F inal Weight Weight Loss Log (m ins) wi(g) wf(g) ~w = wi-wf(g) (wi-~w)g
IOmins 149.378 147.084 2.294 2.1 67
20 mins 149.378 144.840 4.538 2. 160
30 mins 149.378 142.6 10 6.768 2.154
40 mins 149.378 140.400 8.978 2. 147
50 mins 149.378 138.3 17 11.06 1 2. 140
60 mins 149.378 136.300 13.078 2. 134
Table 3.8 Variation of weight with time during the combustion of diesel in the presence of PKO (6cm3
) as additive for 1 hour vol. of diesel= 15cm3
Time Initial Weight Final Weight Weight Loss Log (m ins) Wi(g) wf(g) ~'v=wi-wf(g) (wi- ~w)g
IOmins 150.219 148.337 1.882 2.1 7 1
20 mins 150.2 19 146.423 3.796 2. 165
30 mins 150.2 19 144.200 6.0 19 2.158
40 mins 150.219 142.209 8.0 10 2. 152
50 mins 150.2 19 140.2 17 10.002 2.1 46
60 mins 150.2 19 138.257 11.962 2. 140
15
Table 3.9 Variation of Weight with time during the combustion of diesel in the presence ofPKO (6cm3
) as additive for 1 hour Vol of diesel = 15cm3•
Time Initial Weight Final Weight Weight Loss Log (m ins) wi(g) wf(g) t.w = wi-wf(g) (wi-Lnv)g
IOmins 151.167 149.278 1.889 2. 173
20 mins 151.167 147.4 10 3.757 2. 168
30 mins 15 1.167 145.500 5.607 2. 162
40 mins 15 1.1 67 143.326 8. 188 2. 156
50 mins 15 1.1 67 141.300 9.867 2.1 50
60 mins 151.167 139.329 11.838 2.144
Table 3.10 Variation of weight with time during the combustion of diesel in the present of PKO (7 cm3
) as additive for 1 hour Vol. of diesel = 15cm3•
Time Initial Final Weight Weight Loss Log (m ins) Weight wi(g) wf(g) t.w = wi-wf(g) (wi-t.w)g lOmins 152.5 14 150.871 1.643 2. 178
20 mins 152.5 14 149. 116 3.398 2. 173
30 mins 152.5 14 147.361 5.51 3 2.168
40 mins 152.51 4 146.038 6.476 2. 164
50 mins 152.5 14 144.643 7.871 2. 160
60 mins 152.5 14 143. 11 2 8.392 2. 155
Table 3.11 Variation of weight with time during the combustion of diesel in the
3 cm3 prese nee of PKO (8cm ) as additive for 1 hour vol. of diesel = 15 Time Initial F inal Weight Weight Loss Log (mins) Weight wi(g) wf(g) t.w = wi-wf(g) (wi- t.w)g
lOmins 153.520 152.1 58 1.362 2.182
20 mins 153.520 150.565 2.955 2. 177
30 mins 153.520 149.1 00 4.420 2. 173
40 mins 153.520 147.676 5.844 2.1 69
50 mins 153.520 146.309 7.2 11 2.165
60 mins 153 .520 145.000 8.520 2. 161
16
Table 3.12 Variation of weight with time during the combustion of diesel in the prese 3 5cm3 nee of PKO (9cm ') as additive for 1 hour vol. of diesel = 1
T ime Initial Fina l Weight Weight Loss Log (mins) Weight wi(g) wf(g) ~w = wi-wf(g) (wi-6w)g IOmins 154. 136 153.688 0.488 2.186
20 mins 154.136 152.589 1.747 2.182
30 mins 154. 13 6 15 !.!52 2.984 2.179
40 mins 154.136 150.959 3.177 2. 178
50 mins 154. 136 149.932 4.204 2.175
60 mins 154. 136 148.900 5.236 2 .1 72
Table 3.13 Variation of weight with time during the combustion of diesel in the
3 15cm3 presence of PKO (10cm ) as additive for 1 hour Vol. of diesel = Time In itial Weight Fina l Weight Weight Loss Log (wi- 6w)g (m ins) wi(g) Wf(g) 6 w = Wi-Wf(R:) IOmins 155.082 154. 148 0.934 2.187
20 mins 155.082 153.322 1.760 2.185
30 mins 155.082 152.642 2.440 2.183
40 mins 155.082 152.075 3.007 2.182
50 mins 155.082 15 1.660 3.422 2. 180
60 mins 155.082 15 1.082 5.000 2.176
17
' J i
i I
I
I
CHAPTER FOUR DISCUSSION
4.1 HEAT OF COMBUSTION OF PURE DIESEL
Combustion of Diesel
The combustion of diesel is essentially a thermochemical process
resulting in part or the entire diesel molecule being converted to carbon (IV)
oxide vapour according to the general equation.
CxHg(g) + (x + y/4) 02(g) -----. y/2H20(g) + xC02(g)
4.1.1. The Effect of PKO on the Combustion Rate of Diesel
The combustion rate of pure diesel sample and in the presence of
various concentrations of palm kernel oil (PKO) was investigated. The
results obtained are recorded in table 3.1 and in Fig 3.13.
Fig. 3.1 shows the variation of combustion rate of diesel with various
concentrations of PKO. It was observed that the combustion rate decreases
in the presence of the additive and tends to reach a minimum at 4cm3 of the
15cm3 of the diesel sample. A gradual increase in the combustion rate has
been observed when the volume of the additive has been increased above
4cm3 in the same volume of the diesel before it maintains a constant value
from 7cm3 and above.
18
As shown in Table 3.1 a combustion rate of 2.1 4 x 10-4 cm3/sec was
obtained for pure diesel sample while the combustion rate in the presence of
the PKO (4cM3) was found to be 1.60 x 10-4cm3/sec.
The effect of the additive is in accordance with the report given by
Maron and Lando (1974). According to the authors a functional additive like
Tetraethyllead (IV) TEL, Pb (C2H5)4 increases the octane rating of low grade
petroleum fraction by slowing down the combustion rate of the hydrocarbon.
The modified fuel when applied to automobile engines is able to burn
smoothly without "knocking" the additive could therefore be called an anti
knock.
4.1.2. The Effect of PKO on the heat of combustion of Diesel Sample.
Table 3.2 shows the influence of PKO on the Heat of Combustion of
diesel sample. The heat of combustion values tends to increase up to the
additive concentration of 4cm3 and then maintains a constant value. The heat
of combustion value obtained for diesel as recorded in the table is
-1500KJ mor1, the negative sign signifying that the combustion process was
exothermic.
The heat of combustion values of - 1590 KJmor1 was obtained when
1 cm3
of the additive was added and a maximum value of -1842 KJmor 1 was
obtained with the additive concentration of 4cm3. As observed in Fig. 3.2 the
curve tends to rise gradually to a maximum value at the additive
concentration of 4cm3 and then runs parallel to the x-axis, showing that
19
..,./ ~.- , -1
,...,..I n-e I
I I I
'
r
f- 1--I ·-
~ ~ . ... 2: l ' j I
~ ,..
I
i+ J,{-+. + -~~~
- t::!.:
:- I &: ..
;
~ r; I• :~
I
~::
:d
1-, t-:.:;
S-3
··-·+ ,-·;::j.
' -t- .
! r I
-'-I
1---..L I
,~··
N ; I -,
:I
H-
I I I
I
·"rt'i..(l ~
- '
'
,_:._ -
f-+ --!-
J ~
-P
~. \
:T
>~ __ ["
'
...
- .,
2 -~ - .
I
i
I I
I'
'' I' I
I I I
i
, . lt I
/0
' I
/ '
I• I I
...... . . ., .. .. ~ ... .... _ ... _, ... _11'
f-lo~ bw
-~/0
higher volumes of the additive (above 4cm3 to 15cm3 of the diesel sample)
may not have a significant effect.
The rise in the values of the heat combustion in the presence of the
additive show that more work is done by the hydrocarbon. (Onochukwu
1996).
4.2 APPLICATION OF THE PRINCIPLE'S OF CHEMICAL KINETICS TO THE PRESENT RESULT
The combustion of diesel samples just like any other hydrocarbon is a
thermochemical process (Anusiem 1998). It is on this basis that kinetic
analysis of the data is considered necessary.
Fig. 3.3 and 3.4 show the variation of weight with time for pure diesel
and in the presence of various concentrations of the additive. A plot of Log
wf (the Log of the final Weight) against time) gave a linear variation which
confirms a first order reaction kinetics with respect to the combustion
process.
Table 3.3 to 3.13 records the weight loss values with time during the
combustion process. As observed in the tables lesser quantity of diesel is
burnt in the presence of the additive than was obtained for pure diesel. The
reduction is the quantity of diesel burnt is in agreement with the lowering of
the combustion rate and suggests that the additive enhance both combustion
efficiency and fuel conservation.
22
--
] 1 .I
.. .. j
l
3)
I
-~
'
I I
..... I.
kl Y '
f
l
\ 1
! ., 1 -t ' _, I • l
""' r {
-;
i j < !
1 r
l -;
! I
'
' i ~ ' ' l .! \
4.2.1 Rate Constant and Half-life
Table 4.1 records the rate constant values cm3 /sec as well as Half life
(seconds) for the combustion of pure diesel sample and with the additive
(PKO).
For pure diesel sample, the rate constant recorded was 0.86 x 10·5cm3
sec with a corresponding half life of 80581.3 seconds. With the additive
concentration of 3cm3 and 4cm3 a lower rate constant value of 1.85 x 1 o-s and
2.54 x 10-5 respectively, with a co1Tesponding half life of 37459.4 and
27283.4 respectively was recorded.
This observation reveals that the PKO has actually enhanced the
conservation of the hydrocarbon (diesel) under study by reducing the
combustion rate.
The increase half-life values corresponding to the increased
concentration ofthe additive (PKO) is clearly reflected in Table 4.1.
TABLE 4.1 Rate constants and half life for the combustion of pure diesel and in the presence of various concentrations of PKO as additive. Time =
Vol. PKO Rate constant (CM3Sec-1) Half Life Sec.
Ocm3 0.86 X 1 o·5cm3 SeC-! 80581.3 1cm3 2.76 x 10·5cm3 sec·1 25108.6 2cm3 2.49 X 1 0·5 Cffi3 sec·! 27831.3 3cm3 1.85 x 10-5cm3sec·1 37459.4 4cm3 - ' I 2.54 x 10·) cm'sec· 27283.4 5cm3 2.22 x 10·5 cm3 sec·' 31216.2 6cm3 2.05 x 10·5 cm3 sec·1 33804.8 7cm3 1.85 X 1 o·S cm3 sec·l 37459.4 8cm3 1.58 x 10·5 cm3 sec· ' 43860.7 9cm3 1.03 X 1 0-S cm3 sec·! 6728 1.5 10cm3 0.81 X 1 o·S cm3 sec·! 85555.5
25
4.3 MECHANISM OF THE ACTION OF PKO WITH THE DIESEL SAMPLE
The chemical interaction of the PKO molecule with the diesel
molecule could best be understood using infrared spectrophotometric
technique. Fig 4.1 shows the infrared spectrum of the pure diesel sample
under investigation.
The pure diesel sample shows strong and broad absorption near
3413 .14cm·3 which probable indicates 0-H stretch may be attributed to traces
of alcohol or water molecules, which may likely be bonded to the diesel
molecule.
Strong intensity absorption is obtained 3000cm·3, which probably
indicates a - CH aliphatic stretch for saturated hydrocarbons. Medium and
strong peaks are also seen near 137lcm·3 and 1460cm·3 respectively
signifying CH3 =and CH2 - saturated alkane. The weak absorption obtained
near 745cm-3 suggests some traces of aromatic substance example phenol,
which is usually an impurity in fuels. (Kriz, Lampman and Pavia 1987)
Fig 4.2 shows the infrared spectrum ofthe mixture of pure diesel with
palm kernel oil.
The broad absorption peak near 3413cm·3, which indicated the OH
stretch, was seen to be absent when the diesel has been mixed with the PKO.
These suggest that the PKO probably act by reacting with the OH - group to
convert the water molecule. The removal of the OH group by the PKO
corresponds with the introduction of a C = 0 bond near 1748cm·3 . The
overall mechanism shows that a hydrogen atom is substituted for a carbon
atom as reported by (Bassier, Morril and S ilverstein 1987).
Carbon atom has greater heat-enhancing efficiency than hydrogen atom.
26
Blr] I
...J w Cl) w c w 0:: ;:) a.
6
%
I 34 13 14 3432 25 T 0- f-1 stretch
a I Strong and Broad
n Alcohols & Phenols s m
4
I a n c e
2o-
4000 3500
I I
3000
C -H Stretch
Alkane C- H Saturated
CH, C-H Alkane Bend
(CH3) 2 CH2
A lkane
CH3
C-1-1 Methyl Bend
1377.15
1 ho-pmpyl 'Piit
Methyl & Methylene
1460.38
745.17
C -H Out-of-plane Aromatic Rings
2500 1500 -r--~~---.--~-~~·--..,--~-...---..----,.---.--~--.--~--.,-.,....J
2000
Wavenumbers 1000 500
1'-N
•
...J
0 ...J w z 0:: w ~
:a: ...J < a. + ...J w C/) w i5
% 6
T r a n s m i t t 4
8
11 c e
2
C-H Stretch
Alkane C-H Saturated
c = 0 Esters
CH, C-H
1746.41
Alkane Bend
1158.67
(CI-13) CH
CH, C-H Alkane Bend
1377.12
1 l•o-pw pyl •plit
M ethyl & Methylene
!460..40
CH I -· ····-~----· ····-..--~·-~-~-~~~~-~-~-~-.--~-~---~-.,--.-~-~----,---~-~-.-~---....
4000 3500 3000 2500 2000
Wavenumbers
1500 1000 500
CO N
I
I I I I I I
CHAPTER FIVE
CONCLUSION AND SUGGESTIONS FOR FURTHER INVESTIGATIONS
5.1 CONCLUSION
The principal aim of this study was to investigate the effect of Palm Kernel
Oil on the heat of combustion of Diesel. From the investigation the
following conclusions are deduced.
1. Palm Kernel Oil has proved effective in lowering the combustion rate
of Diesel and thus increases the Heat of Combustion for higher energy
performance.
2. Palm Kernel Oil if researched upon could serve as anti-knock agent to
our automobiles.
3. The research has offered a preliminary breakthrough whereby variety
of local oils could be tested on our fuels to select the best among them
that can act well in the mixture of a pm1icular hydrocarbon to enhance
combustion efficiency.
4. From this investigation it could be observed that PKO as an additive
enhances fuel conservation.
29
5.2 SUGGESTIONS FOR FURTHER INVESTIGATION
Having investigated the effect of Palm Kernel Oil on the heat of
combustion of diesel, I wish to make the following suggestions for further
studies which will aid in the understanding of the mechanism of action of an
efficient additive capable of slowing down the combustion rate of a
hydrocarbon thereby decreasing the knocking potentials of our fuels. Hence,
due to time and financial constraints the researcher wishes to suggest the
following:
· 1. That extensive investigation be carried out on the effect of
other local oil on the combustion efficiency of diesel and other
fuel samples.
2. A bomb calorimeter should be used to test whether this present
result obtained is in agreement with the data obtained from the
method.
3. Some other spectrophotometric technique such a U-V
technique should be adopted to investigate the mechanism of
the action of the additives.
4. Animal fat should be extracted and tested as modifiers of fuel
samples to ascertain the extent of their effects on the heat of
combustion.
5. The modified fuels should be tested on automobile engines to
appreciate the difference.
30
REFERENCES
Ababio, 0 . Y. (1998) New School Chemistry 41h Edition
Africana-FEP Publishers Limited, Nigeria pp 112-120,
201-202.
Anusiem, A. C. I. (1998) Basic Chemical Thermodynamics.
Great Versatile Publishers Ltd., Owen·i, Nigeria pp. 54.
Beer, J. M. (1997) "Combustion" Mac Graw Hill Encyclopedia of
Science and Technology 8111 Edition
Mac Graw Hill, New York. Vol. 4, pp 202.
Hampel, C. A., Hawley, G. G. (1973) The Encyclopaedia of
Chemistry. 3rd Edition Van Nostrand Reinhold Company,
New York. pp.290.
Hendrickson, J. B.; Gram, D. J. Hamond, G. S. ( 1978)
Organic Chemistry 3rd Edition Mac Graw Hi ll
New York pp 256-263.
http://www .lubrizo l.com/referencel i brary/readyreference/8. fuels/fueltext.htm
pp. 4-7 Internet ( 1999)
Maron S. H.; Lando, J. B.; (1974) Fundamentals of Physical
Chemistry. Macmillian Publishing Co Inc pp. 275-276
Morrison, R. T.; Boyd, R. N.; (1983) Organic Chemistry 4th Edition
Allycon and Bacon, Boston. pp. 680-685.
31
l _.
Norris, F. A .. (1969) "Fats and Oils" Encyclopaedia of Chemical
Technology 2nd Edition
John Wiely and Sons Inc Vol.8 pp 777-794
Onochukwu, A. I. ( 1996) Chemical Thermodynamics for Sciences
Students. Futo Press, Owerri .
Paria, D. L. , Lampan, G. M. Kris G. S. (1987) Introduction of
S pectroscopy
Saunders College Publishing, West Washington Square, Philadelphia
pp. 27.
Ryer, F. V. (1969) "Soap" Encyclopedia of Chemical Technology
2"d Edition John Wiely and Sons Inc. Vol. 18 pp. 417.
Silversten, R. M.; Bassier G. G.; Morril, T. C. (1987) Spectrometric
Identification of Organic Compounds
John Wiely and Sons Inc. pp.36
Speight, J. G. (1997) "Diesel Fuel" Mac Graw Hill Encyclopaedia
of Science and Technology 81h Edition
Mac Graw Hill New York. Vol. 5 pp. 239-240,
Vol.l3 pp320-325 .
Uttong, U.M,(l998) Comparative Study ofthe Effect ofNitrogen and
Chlorine atoms on the Exothermal potential of Trioxonitrate (V) Acid
and Hydrochloric acid at various dilution. An unpublished project
presented to the Dept of Chemistry . Uniuyo. pp 46-50.
32
I
APPENDIX 1
Determination Of The Heat Of Combustion Of Pure Diesel
EXPERIMENT RESULTS
Initial temperature of water 30°C = 303k
Final temperature of Water = 56°C = 329k
Mass of Water in Beaker = lOOg
Mass of Lamp + diesel before burning = 149.214
Mass of Lamp + diesel After burning = 147.614
Specific heat capacity of water = 4.2 Jg- IK-1
CALCULATION
To calculate the heat of combustion of diesel, first we find the amount
of heat energy off and the amount of diesel burned during the process.
The amount of heat energy given off is that which raised the
temperature of lOOg of water (specific heat capacity = 4.2Jg -IK-1) from
303k to 329K.
Heat evolved = mass x specific beat capacity x temperature rise
= 100x4.2 (327-302)1
10500
33
Mass of diesel burned = (14.214 - 147-614)g
= 1.6g
Since the number of carbon atoms in diesel ranges between C 14 - C 18; this
project rather assumes the relative molecular mass of the diesel to reflect the
averaging of the carbon atom range, that is C 16H34 (Ababio, 1998).
Hence, relative molecular mass of diesel C16H34 = 226
Number of moles of diesel burned = 1.6
226
= 0.0070
mole
Combustion of 0.0070 mole of diesel produces 1 0920J of heat energy
1 mole diesel produces 10500
0.0070 = 1500
Conclusion: The heat of combustion of diesel is - 1500 KJmor1
Combustion rate of diesel
149.214g of diesel has a vol of 15cm3
1 g of diesel has a vol of 15 cm3
149.214
1.6g of diesel has a vol. of 15 x 1.6cm3
Combustion rate =
=
149.214 = 0.160
.n 0.16cm3
Volume burned Time taken
0.16cm3
560sec 2.85 X 1 0"4 cm3 /sec
34
APPENDIX2
Determination of the Heat of Combustion of diesel in the presence ofPKO as
additive.
Vol. of Diesel=
Vol. ofPKO =
Initial Temperature ofwater = 28°C = 301K
Final Temperature ofwater = 53°C = 326K
Mass of Water In Beaker = lOOg
Mass ofLamp + Diesel + PKO before burning = 148.719
Mass ofLamp +Diesel + PKO after burning = 147.207
Specific heat capacity of water = 4.2 Jg-1K-1
Heat evolved = Mass x specific heat capacity x temperature rise
100 X 4.2 X (326 - 30l)J
= 100 X 4.2 X 25J
10500J
Mass of diesel burned = (148.7 19 - 147.207)g
1.5g
Relative molecular mass of diesel = C1 6 H34 = 226
:. No of moles of diesel+ PKO burned = 1.5 226
0.0066
35
Combustion of0.0066 moles ofPKO produces 10500 J of heat energy
1 mole of diesel + PKO produces 10500
0.0066
= 15901
The heat of combustion of diesel + PKO = -l590KJ m or '
Combustion rate
148.719g of mixture has a vol. of 16cm3
1g of mixture has a vol of 16
148.719
1.5g of mixture has a vol of 16 x 1.5cm3
148.719
= 0.162 cm3
Combustion Rate Volume burned
Time taken
= 0.162cm3
837 sec
This procedure was repeated for a range of concentrations of PKO from 2cm3
to 1 Ocm3 while the volume of diesel remained constant.
36
APPENDIX3
Determination of Rate Constants and Half life for the combustion of
pure diesel sample and in the presence of various concentrations of the
additive (PKO)
For pure diesel
Rate constant
K = 2.303 Log _w_I _ _
Where t = time
Wi
Wi-~:,.w
K
2.303
t WI- t:,.W
= Initial weight
= Variation in weight
= Rate Constant
= Constant
K = 2.303 Log WI t WI - t:,.W
Time 30 mins = 30 x 60 secs = 1800secs
Half li fe
K = 2.303 Log 146.826 1800 144.443
0.001279 Log 1.016 0.001279 X 0.068
== 0.66 t = 0.693 % K
= 0.693 0.86 x w-5
= 80581.3 secs. This procedure was repeated to determine that of the mixture at various
concentrations.
37