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