Investigating the Potential of Biodiesel Production In...

Investigating the Potential of Biodiesel Production in Fiji:

Facilitating Sustainable Production in the Fiji Region

By

Radhika SINGH (BSc, PG Dip. Chem.)

A Thesis Submitted in Partial Fulfillment of the Requirements for the degree of

Master of Science in Chemistry

School of Biological and Chemical Sciences, Faculty of Science, Technology and Environment,

The University of the South Pacific.

November, 2008

ii

DECLARATION

I hereby declare that the work contained in this thesis is my very own and where I have used the thoughts and works of others I have clearly indicated this. Researcher:

Radhika Singh S01006753

We hereby confirm that the work contained in this thesis is the work of Radhika Singh unless otherwise stated. Principle supervisor: ____________________

Dr. Vincent. W. Bowry University of the South Pacific

Co-Supervisor 1: ____________________

Professor Subramanium Sotheeswaran University of the South Pacific

Co-Supervisor 2: ____________________

Associate Professor Sadaquat Ali University of the South Pacific

iii

DEDICATION

I would like to dedicate this thesis to my parents

Surendra Singh and Arun Kumari

for their invaluable love and support.

Thanks.

iv

ACKNOWLEDGEMENTS

This research has been exciting and sometimes challenging, but always an interesting

experience. It has been made possible through the support and encouragement of many

other people.

I would like to thank my research supervisors: Dr. Vincent Bowry, principle

supervisor, for his encouragement, guidance and correction of the manuscript; co-

supervisors, Professor Subramanium Sotheeswaran and Associate Professor

Sadaquat Ali, for their input and providing financial assistance from the Natural

Products funds.

This project was undertaken as part of the Biofuel Research awarded by jointly funded

SOPAC- USP Graduate Assistant Scholarship. I would like to thank Mr. Paul

Fairbain, the Manger of Community Lifelines Programme, SOPAC for providing me

the opportunity to be a part of his team. Also, thanks to Mr. Jan Cloin, Energy Advisor,

for the fruitful discussions on the local biofuel perspective and the staff of Community

Lifeline Programme – Energy Sector, for their cooperation and assistance in

literature search.

I am thankful to Associate Professor Roger Read for his guidance at the School of

Chemistry, University of New South Wales in the duration of my collaborative studies

there. I am indebted to Dr. Joseph Brophy, Honorary Fellow, for his kindness and

assistance in analysis of the research samples in Gas Chromatography/ Mass

Spectrometry.

I would like to gratefully acknowledge the assistance and cooperation of the chemistry

division technical staff at the University of the South Pacific. Mr. Steve Sutcliffe, Lab

Manager, for his efforts in organising the chemicals and accessories required in this

research and Mr. Sachin Singh, Scientific Officer, for providing training on

instrumentation and professional assistance. I would also like to thank Dr. Culwick

Togamana for his support.

v

I wish to thank the Managers of franchise companies for providing valuable samples,

whose names cannot be disclosed as part of the agreement to take part in this research.

I would like to acknowledge my loving husband Mr . Sachin Singh, for his guidance

and support.

Finally, thanks to my sister, Mrs. Sarika Dayal and my brothers, Mr. Sachindra

Singh, Mr. Ram Aman Singh and Mr Rajeev Singh. It is always a privilege to be in

their company.

vi

ABSTRACT

Biodiesel an alternative renewable energy resource produced from alcohol and

vegetable oil. Its production and quality control has been explored extensively using the

available local raw materials. The final Biodiesel fuel produced has been characterised

by examining it physical and chemical properties.

Coconut oil was found to be the most suitable vegetable oil raw material having iodine

value of 7.9, free fatty acid content of 3.72%, less than 1% moisture content and non

detectable phosphorus content. These chemical analyses were carried out by

standardised AOCS methods. Other lipid sources investigated included used vegetable

oil (sourced from various franchise companies locally), canola oil and soybean oil.

Ethanol has the potential to be produced locally and thus was deemed as an alcohol

source. Methanol was also investigated. The catalysts investigated were sodium and

potassium hydroxide.

The synthetic methods investigated were designed to suit the FFA content of the lipid

raw materials used. These include Acid pretreatment, one step base catalyzed

transesterification (Method 1), One step base transesterification (Method 2A), Two step

base transesterifcation (Method 2B) and Base neutralization, one step base

transesterification (Method 3). Simple gravitation separation of glycerol layer was an

effective method of glycerol removal. This was confirmed by FTIR spectrometry

technique. Saline water washing was found to be most effective in removing

saponification products from the crude biodiesel mixture.

vii

The quality of the Biodiesel fuel produced using these methods were determined by

chemical and physical analysis. Gas chromatography (FID and MS) and Gel

Permeation Chromatography were employed to identify and quantify the alkyl ester and

total and bound glyceride content. These two methods were found to be a

complementary as far as the production and quality control of the final product is

concerned. Viscosities of the esters were also measured.

viii

TABLE OF CONTENT

DECLARATION ....................................ERROR! BOOKMARK NOT DEFINED.

DEDICATION.........................................................................................................III

ACKNOWLEDGEMENTS..................................................................................... IV

ABSTRACT............................................................................................................ VI

TABLE OF CONTENT ........................................................................................VIII

ACRONYMS AND DEFINITION.......................................................................... XI

LIST OF FIGURES...............................................................................................XIII

LIST OF TABLES .................................................................................................XV

1 CHAPTER 1: GENERAL OVERVIEW .................................................... 1

1.1 INTRODUCTION ...................................................................................... 1

1.2 AIMS ......................................................................................................6

2 CHAPTER 2: LITERATURE REVIEW AND BACKGROUND ........ ..... 7

2.1 HISTORY ................................................................................................ 7

2.2 GLOBAL PERSPECTIVE AND BIODIESEL STANDARDS ............................. 9

2.3 REGIONAL PERSPECTIVE AND PRODUCTION ....................................... 12

2.4 ENVIRONMENTAL BENEFITS OF BIODIESEL ......................................... 16

3 CHAPTER 3 – RAW MATERIALS – FEEDSTCK AVAILABLITY AN D

ANALYSIS................................................................................................. 21

3.1 INTRODUCTION .................................................................................... 21

3.2 IDENTIFYING & SURVEYING EDIBLE OIL FEEDSTOCKS. ..................... 23

3.2.1 Lipid source material........................................................................ 23

3.2.2 Alcohol as raw material.................................................................... 28

3.3 METHODOLOGY : ANALYSIS OF RAW M ATERIALS ............................... 32

3.3.1 Sampling methods............................................................................ 33

3.3.2 Chemical Analysis ........................................................................... 34

3.3.2.1 Free Fatty Acid (FFA) .............................................................. 34

3.3.2.2 Iodine Value (Wijs’ Method).................................................... 37

3.3.2.3 Phosphorus Analysis................................................................. 39

3.3.3 Physical Properties ........................................................................... 42

ix

3.3.3.1 Moisture and Volatile Matter.................................................... 42

3.4 RESULTS AND DISCUSSION ................................................................... 44

3.4.1 Chemical Analysis of Raw Materials................................................ 44

3.4.1.1 Free Fatty Acid Content............................................................ 44

3.4.1.2 Iodine Value............................................................................. 45

3.4.1.3 Phosphorous content................................................................. 46

3.4.2 Physical Analysis of Raw Materials ................................................. 48

3.4.2.1 Moisture content....................................................................... 48

3.4.3 Raw Material Used in this Research: Logistics Study ....................... 49

3.4.3.1 Lipid Raw Material................................................................... 50

4 CHAPTER 4 SYNTHESIS AND PURIFICATION................................. 52

4.1 INTRODUCTION .................................................................................... 52

4.2 METHODOLOGY .................................................................................. 58

4.2.1 Synthesis Process ............................................................................. 58

4.2.1.1 Method 1 Acid pretreatment, one-step base-catalysed

transesterification .................................................................... 60

4.2.1.2 Method 2A - One Step Base Transesterification (No pretreatment)

................................................................................................ 66

4.2.1.3 Method 2B – Two-Step Base Transesterification (No pretreatment)

................................................................................................ 70

4.2.1.4 Method 3 Base Neutralisation, One Step Base Transesterification71

4.3 RESULTS AND DISCUSSION................................................................... 75

4.3.1 Method Optimization ....................................................................... 75

4.3.2 Observations and results for the methodology used to prepare biodiesel

......................................................................................................... 79

4.3.3 Observations and results for purification process.............................. 83

4.3.3.1 Washing Method optimization.................................................. 83

4.3.3.2 Comparison of washing processes using distilled water and saline

water ....................................................................................... 85

5 CHAPTER 5 CHEMICAL AND PHYSICAL ANALYSIS OF BIODIES EL

.................................................................................................................... 89

5.1 INTRODUCTION .................................................................................... 89

5.2 METHYL AND ETHYL ESTERS (BIODIESEL ) .......................................... 95

5.2.1 Gas Chromatography – Flame Ionisation Detector (FID).................. 95

x

5.2.1.1 Methodology ............................................................................ 95

5.2.1.2 Results...................................................................................... 98

5.2.1.3 Discussion .............................................................................. 101

5.2.2 Gel Permeation Chromatography.....................................................107

5.2.2.1 Methodology101 ...................................................................... 107

5.2.2.2 Results.................................................................................... 112

5.2.2.3 Discussion .............................................................................. 116

5.3 MONO-, DI- AND TRIGLYCERIDES (FREE AND TOTAL GLYCERIDES ) ....120

5.3.1 Gas Chromatography.......................................................................120

5.3.1.1 Methodology102 ...................................................................... 120

5.3.1.2 Results and Dicussion............................................................. 123

5.3.2 Gel Permeation Chromatography.....................................................124

5.3.2.1 Methodology .......................................................................... 124

5.3.2.2 Results.................................................................................... 129

5.3.2.3 Discussion .............................................................................. 133

5.3.3 Gas chromatography – Mass Spectrometry......................................139

5.3.3.1 Methodology .......................................................................... 139

5.3.3.2 Results.................................................................................... 140

5.4 PHYSICAL ANALYSIS ..........................................................................141

5.4.1 Viscocity.........................................................................................141

5.4.1.1 Methodology .......................................................................... 141

5.4.1.2 Results.................................................................................... 141

5.5 IN SUMMARY ......................................................................................142

6 CHAPTER 6 CONCLUSION AND RECOMMENDATION ............ .....145

REFERENCE.........................................................................................................151

APPENDIX............................................................................................................164

xi

ACRONYMS AND DEFINITION

Acronyms

ASTM American Standard Test Material

SOPAC Pacific Islands Geoscience Commission

COCOHOL Esterified Coconut Oil

SPC-CIRAD Secretariat for Pacific Commission – Agricultural Research

Centre for International Development.

PAH Polycyclic Aromatic Hydrocarbon.

NEB Net Energy Balance

GC-FID Gas Chromatography Flame Ionisation Detector

CI Compression Ignition

SI Spark Ignition

CEN European Committee of Standardisation

ROME Rapeseed Oil Methyl Ester

FAMAE Fatty Acid Monoalkyl Ester

FAME Fatty Acid Methyl Ester

VOME Vegetable Oil Methyl Ester

TG Triglyceride

DG Diglyceride

MG Monoglyceride

FFA Free Fatty Acid

AOCS American Oil Chemist Society

xii

Definitions

Viscosity The resistance of the fuel to flow at a given temperature.

Measured by ASTM D445 method.

Cetane Number The percentage of cetane (C16H34) in a amixture of ceatane and

methylnaphthalene that has the same ignition delay as the test

fuel, the higher the cetane number the shorter the ignition delay

(ASTM D613)

Flash Point

the temperature in which a liquid can be ignited in air (ASTM

D93).

Cloud Point

The temperature below which an oil becomes cloudy due to

crystal formation. Higher values give better performance in cold

conditions (ASTM D2500)

Pour Point

The temperature below which an oil ceases to flow under

prescribed conditions (per ASTM D97)

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LIST OF FIGURES

Figure 1.1 Transeterification of Triglycerides·····························································3

Figure 1.2 Chemical Structures of Oil, Biodiesel and Petrodiesel. ·······························4

Figure 2.1. Coconut Oil Production Potential and Exports of Pacific Island Countries19.

······················································································································ 12

Figure 2.2 Biodiesel Batch Process Plant at Lami. ···················································· 14

Figure 2.3 Some PAHs Emitted from Diesel Exhaust ··············································· 16

Figure 3.1 Lipid Classes and Some Fatty Acids and Found in Edible Oils.················· 23

Figure 3.2 Chemical and Physical Analysis of Lipid Raw Materials ·························· 32

Figure 3.3 Calibration Graph of Phosphorous Standards ··········································· 47

Figure 4.1 Transesterification of triglycerides - Three-step consecutive reactions······· 52

Figure 4.2 Mechanism of Acid Catalysed Transesterification of Lipids.····················· 54

Figure 4.3 Mechanism of Base Catalysed Transesterification of Lipids87··················· 55

Figure 4.4 Soap formation due to high FFA and deactivation of catalyst during Base

catalysed transesterification process ·································································56

Figure 4.5 Successful ester (biodiesel) synthetic methodologies. ······························· 58

Figure 4.6 Fate of Lipid Feedstock Depending of their Free Fatty Acid Content.········ 59

Figure 4.7 Flowchart Illustrating Procedure for Method 1········································· 60

Figure 4.8 Flowchart Illustrating Procedure for Synthetic Method 2A························ 67

Figure 4.9 Flowchart Illustrating Synthetic Procedure for Method 2B························ 70

Figure 4.10 Flowchart Illustrating Synthetic Procedure for Method 3························ 71

Figure 4.11 Miscibility Problems during Synthesis of Biodiesel································ 75

Figure 4.12 Treatment of Reaction Mixture to Obtain Purified Biodiesel ·················· 80

Figure 4.13 Soap formation while washing crude biodiesel (methanolysis) ··············· 81

Figure 4.14 Excess Soap Formation while Washing Crude Biodiesel (ethanolysis)····· 82

Figure 4.15 Infra Rad Spectra of Ester Before Purification Process ··························· 87

Figure 4.16 Infra Rad Spectra of Ester After Purification Process······························ 87

Figure 5.1 Intermediates formed from transesterification of trilauric acid ·················· 90

Figure 5.2 Purified Coconut Oil Methyl Ester Synthesized Using Method 2A.········· 102

Figure 5.3 Percentage of Methyl Laurate in Coconut Oil Methyl Ester (GC-FID)····· 103

Figure 5.4 Purified waste oil methyl ester synthesized using method 3 (GC-FID).···· 104

Figure 5.5 Percentage of Methyl Laurate in Coconut Oil Ethyl Ester (GC-FID) ······· 105

Figure 5.6 Purified Coconut Oil Ethyl Ester (GC-FID) showing similar profile. ······· 106

xiv

Figure 5.7 Calibration Curve of Methyl Oleate······················································· 108

Figure 5.8 Calibration Curve of Methyl Laurate ····················································· 109

Figure 5.9 Calibration Curve of Ethyl Oleate ························································· 109

Figure 5.10 Calibration Curve of Ethyl Laurate······················································ 110

Figure 5.11 Percentage of Methyl Laurate in Coconut Oil Methyl Ester (GPC) ······· 117

Figure 5.12 Percentage of Ethyl Laurate in Coconut Oil Ethyl Ester (GPC) ············· 118

Figure 5.13 Calibration Curve of Trilauric Acid ····················································· 124

Figure 5.14 Calibration Curve of Dilauric Acid······················································ 125

Figure 5.15 Calibration Curve of Monolauric Acid················································· 126

Figure 5.16 Calibration Curve of Trioliec Acid ······················································ 126

Figure 5.17 Calibration Curve of Dioliec Acid ······················································· 127

Figure 5.18 Calibration Curve of Monoliec Acid···················································· 128

Figure 5.19 GPC chromatogram of Coconut oil Biodiesel Sample··························· 134

Figure 5.20 Percentage Concentration of Glyceride content in Coconut oil Methyl

Esters ··········································································································· 135

Figure 5.21 Percentage Concentrations of Glycerides in Coconut Oil Ethyl Esters ··· 136

Figure 5.22 Using Percentage Glyceride Content to Compare Different Synthetic

Methods. ······································································································ 137

xv

LIST OF TABLES

Table 2.1 Diesel Substitutes Made From or Based on Vegetable Oil 13 .........................8

Table 2.2 Fuel Properties of Biodiesel Compared to Conventional Diesel Fuel. ............9

Table 2.3 Biodiesel Fuel Standards in Europe Countries.............................................10

Table 2.4 Fuel Standards for Biodiesel in Australia 18.................................................11

Table 2.5 Coconut oil, Mixtures and Derivatives as Fuel in the Pacific. ......................13

Table 2.6 Emission Change in Biodiesel and Blended Biodiesel Fuel5. .......................18

Table 3.1 Comparisons Between Alkaline and Acidic Catalyst ...................................30

Table 3.2 Fatty Acid Composition of Commercial Oil Samples Analysed6. ................33

Table 3.3 Lipid Source Before Use from Three Different Outlets. ..............................34

Table 3.4 Specifications according to A.O.C.S Ca 5a-40 ............................................35

Table 3.5 Free Fatty Acid Values Reported as the Respective Fatty Acid ...................36

Table 3.6 Recommended Masses of Sample for Iodine Value.....................................38

Table 3.7 Preparation of Phosphorous Standards ........................................................41

Table 3.8 Free Fatty Acid Content of Commercial Oil for Biodiesel Synthesis ...........44

Table 3.9 Free Fatty Acid Content of Waste Oil for Biodiesel Synthesis.....................44

Table 3.10 Iodine values of commercial oil samples ...................................................46

Table 3.11 Iodine values of waste oil samples ............................................................46

Table 3.12 Phosphorous content of commercial oil samples .......................................47

Table 3.13 Moisture Content and Volatile Matter of Commercial Oil Samples ...........48

Table 3.14 Moisture Content and Volatile Matter of Waste Oil Samples.....................48

Table 4.1 Treatment of lipid raw materials undertaken prior to transesterification

reactions to produce biodiesel.............................................................................59

Table 4.2 Molecular weights of Triglycerides in Lipid Raw Material..........................66

Table 4.3 Trial for suitable catalyst for transesterification reaction and its observation76

Table 4.4 Optimizing Pretreatment Coconut Oil Using Acid Catalyst and Methanol...77

Table 4.5 Optimizing Pretreatment Process of Coconut Oil using Acid Catalyst and

Ethanol. ..............................................................................................................78

Table 4.6 Percentage Loss of water soluble during purification of biodiesel synthesized

using the methods investigated. ..........................................................................84

Table 4.7 Purification of Coconut Oil Ethyl Esters with Distilled and Saline Wash

Water..................................................................................................................86

xvi

Table 5.1 Some Common Fatty Acids and There Esters..............................................89

Table 5.2 Property Data for Methyl Ester Biodiesel Fuels 91.......................................91

Table 5.3. Summary of Some Parameters for Analysing Biodiesel in Gas

Chromatography. ................................................................................................92

Table 5.4. Summary of Some Parameters for Analysing Biodiesel by High Performance

Liquid Chromatography97. ..................................................................................93

Table 5.5 Gas Chromatography FID Instrumentation Condition for Biodiesel Analysis

...........................................................................................................................96

Table 5.6 Calculation of the Percentage Methyl Ester in the Samples (GC-FID).........98

Table 5.7 Calculation of the Percentage Ethyl Ester in the Samples (GC- FID)...........99

Table 5.8 Calculation of the Percentage Methyl Ester in the Samples (GC-FID)....... 100

Table 5.9 Calculation of the Percentage Ethyl Ester in the Samples (GC-FID).......... 100

Table 5.10 Percentage Concentration of Methyl Esters Analysed by GC FID ........... 103

Table 5.11 Percentage Concentration of Ethyl Esters Analysed by GC-FID.............. 104

Table 5.12 Peak Area versus Concentration of Methyl Oleate................................... 108

Table 5.13 Peak Area versus Concentration of Methyl Laurate................................. 108

Table 5.14 Peak Area versus Concentration of Ethyl Oleate ..................................... 109

Table 5.15 Peak Area versus Concentration of Ethyl Laurate.................................... 110

Table 5.16 Gel Permeation Chromatography instrumentation conditions for Biodiesel

analysis............................................................................................................. 111

Table 5.17 Concentration of Methyl Oleate in Waste Oil Biodiesel Samples (GPC) . 112

Table 5.18 Concentratrion of Methyl Laurate in Coconut Oil Biodiesel Samples (GPC)

......................................................................................................................... 113

Table 5.19 Concentration of Ethyl Oleate in Waste Oil Biodiesel Samples (GPC) .... 114

Table 5.20 Concentratrion of Ethyl Laurate in Coconut Oil Biodiesel Samples (GPC)

......................................................................................................................... 115

Table 5.21 Percentage Concentration of Methyl Esters Analysed by GPC ................ 116

Table 5.22 Percentage Concentration of Ethyl Esters Analysed by GPC ................... 118

Table 5.23 Glycerides Calibration solutions for contaminants in biodiesel from waste

oil (GC-FID)..................................................................................................... 121

Table 5.24 Gas Chromatography (FID) Instrumentation Condition for Biodiesel

Contaminants Analysis ..................................................................................... 122

Table 5.25 Peak Area versus Concentration of Trilauric Acid................................... 125

Table 5.26 Peak Area versus Concentration of Dilauric Acid.................................... 125

xvii

Table 5.27 Peak Area versus Concentration of Monolauric Acid .............................. 126

Table 5.28 Peak Area versus Concentration of Trioliec Acid .................................... 127

Table 5.29 Peak Area versus Concentration of Dioliec Acid..................................... 127

Table 5.30 Peak Area versus Concentration of Monoliec Acid ................................. 128

Table 5.31 Concentration of Bound Glycerides in Waste Oil Biodiesel Samples....... 129

Table 5.32 Concentration of Bound Glycerides in Coconut Oil Biodiesel Samples ... 130

Table 5.33 Concentration of Bound Glycerides in Waste Oil Biodiesel Samples....... 131

Table 5.34 Concentration of Bound Glycerides in Coconut Oil Biodiesel Samples ... 132

Table 5.35 Molecular weights of components in biodiesel samples analysed ............ 133

Table 5.36 Relative Response Factors of Glycerides to Esters. ................................. 135

Table 5.38 Mass Spectral Data of Fatty Acid Esters Analysed. ................................. 140

Table 5.39 Viscosity of biodiesel samples investigated............................................. 141

Table 5.40 Advantages and Disadvantages of Analysing Biodiesel using GC ........... 143

Table 5.41 Advantages and Disadvantages of Analysing Biodiesel using GPC ......... 144

Table A.15 Pretreatment of Coconut oil - METHANOLYSIS................................... 178

Table A.16 FFA of Pretreated Coconut Oil............................................................... 178

Table A.17 Transesterification of Pretreated Coconut Oil ......................................... 179

Table A.18 Pretreatment of Waste oil – METHANOLYSIS..................................... 179

Table A.19 Transesterification of Pretreated Oil ....................................................... 180

Table A.20 Coconut oil - METHANOLYSIS ........................................................... 181

Table A.22 Soybean oil - METHANOLYSIS ........................................................... 182

Table A.23 Soybean oil – ETHANOLYSIS.............................................................. 182

Table A.24 Canola oil – METHANOLYSIS............................................................. 182

Table A.25 Canola oil – ETHANOLYSIS ................................................................ 183

Table A.26 Transesterification of Waste Oil - ETHANOLYSIS ............................... 183

Table A.27 Transesterification of Coconut Oil - ETHANOLYSIS............................ 184

Chapter1: General Overview

1

1 CHAPTER 1: GENERAL OVERVIEW

1.1 INTRODUCTION

Depletion of the world’s fossil fuels and the high global demand in energy has led to a

relentless increase in fuel prices. Higher fuel prices have led to higher transport and

power costs, which, to make matters worse, have a multiplied effect on the prices of

goods and services. One way of offsetting this trend is to replace fossil fuel – in

dwindling supply and at the mercy of global politics – with renewable energy sources

such as wind, tidal and solar energy, and with biofuels. The replacement of fossil fuels

with renewable sources such as biofuel also benefits the environment since it helps to

reduce noxious emissions and the global warming effect of man-made CO2 emissions.

Security of fuel supply, fuel costs and the effect of fossil fuels on the environment have

become key issues that have spurred countries like Europe, Brazil and United States of

America to invest heavily in biofuel technologies. The United Nations (UN) has been

involved with supporting its member countries to move towards sustainable energy and

to develop it in their regions. The UN monitors the trends of energy production,

distribution and consumption and devises energy strategies, policies and programmes1.

For geographically isolated areas, such as the island nations of the South Pacific, the cost

and logistics of supplying petro-diesel are even more of a burden than in developed

nations. Producing biofuel in Fiji and the regions would improve the security of energy

supply and lead to the positive employment and social benefits of having a domestic

source of energy. Local production of biofuel would stimulate domestic economic growth


2

and reduce the flow of capital offshore by relieving dependence on imported fossil fuel.

In 2006 the Pacific Islands Forum and Secretariat, which monitors Pacific fuel prices,

reported that the prices for kerosene and diesel were at historically high levels for the

early four month period of 20062. Since then the situation has worsened with highest-ever

crude-oil costs driving at-the-pump diesel and petrol prices up by 50% and more on 2007

levels.

Many countries in the South Pacific region have already resorted to biofuel technology to

solve this problem. Countries like Vanuatu, Marshall Islands, Samoa, Solomon Islands,

Papua New Guinea, Kiribati and Fiji, in the South Pacific have all been involved in

projects to assess the biomass of local raw materials in their countries in order to evaluate

the potential of local liquid biofuel production3. Vanuatu, the Solomons and Samoa have

replaced significant amounts of the diesel and kerosene used in generators, heaters and

lamps with local coconut oil. So far, this has only involved the edible oils themselves and

not chemically modified derivatives of the oils.

This research project explores the possibilities of a sustainable, alternative energy

resource for Fiji and the region. It focuses on the chemically modified (alcoholized)

product of vegetable oil commonly known as biodiesel as an alternative to diesel fuel.

The research examines chemical aspects of the process (as tested on various lab scales)

when it is applied to relevant oils such as coconut and available waste (used) oils. The

project has been aided in both investigation and application stages by SOPAC and by


3

private enterprise with a view to supporting the production and quality control of

biodiesel in Fiji.

What is biodiesel ?

According to the specification for biodiesel (B100) American Standard Test Material

ASTM D6751-07a, biodiesel is defined as the

“monoalkyl esters of long chain fatty acids derived from renewable feedstock

such as vegetable oil or animal fat for use in compression ignition engines”4.

Bio-diesel is usually made by treating a fat or oil (trigyceride) with methyl or ethyl

alcohol and a small amount of a strong base such as sodium or potassium hydroxide as a

catalyst. Thus, e.g., coconut oil (consisting mainly of glyceryl trilaurate) when treated

with methanol (MeOH) containing a small amount of sodium hydroxide gives glycerol

(which separates as a byproduct) and coconut biodiesel (consisting mainly of methyl

laurate), as shown below (figure 1.0).

Figure 1.1 Transeterification of Triglycerides

CH2

CH

CH2

C11H22CO2

C11H22CO2

C11H22CO2

+ 3 x MeOH

CH2

CH

CH2

HO

HO

HO

base or acidcatalyst

+ 3 x C11H22CO2Me

glyceroltriglyceride

"biodiesel"(coconut methyl ester in

this example)


4

The resulting long-chain fatty-acid esters, unlike the thicker parent oil, can safely be used

in unmodified diesel engines. The molecular structure of biodiesel is quite similar to

petrodiesel, see below.

Figure 1.2 Chemical Structures of Oil, Biodiesel and Petrodiesel.

The key difference between petrodiesel and biodiesel is replacement of a short segment

of the non-polar hydrocarbon chain by a polar carboxyl (CO2) group (figure1.1).

Accordingly, biodiesel made from various edible oils have similar viscosities to

petrodiesel5 and “engine performance of neat biodiesels and their blends was similar to

that of No. 2 diesel fuel with the same thermal efficiency, but higher fuel consumption.”6.

In comparison with unmodified vegetable oil, biodiesel eliminates the problems of engine

choking, deposit formation and ring sticking.

H3C

H2C

CH2

H2C

CH2

H2C

CH2

H2C

CH2

H2C

CH2

H2C

CH2

H2C

CH2

CH3

petrodiesel (represented by cetane, C16H34)

CCH2

H2C

CH2

H2C

CH2

H2C

CH2

H2C

CH2

H2C

H3C

O

OC

coconut biodiesel (represented by methyl laurate)

OH2C

CHO

H2C O

C CH2

H2C CH2

H2C CH2

H2C CH2

H2C CH2

H2C CH3

CH2C

CH2H2C

CH2H2C

CH2H2C

CH2H2C

CH2H3C

C CH2

H2C CH2

H2C CH2

H2C CH2

H2C CH2

H2C CH3

coconut oil (represented by trilauryl glycerol)

O

O

O


5

Biodiesel has technical, practical and environmental advantages over petrodiesel. Thus,

it has a higher lubricity value, leading to less engine wear7. Compared to petro-diesel,

bio-diesel offers: a) a higher cetane rating8; b) a higher flashpoint (making it safer to

handle); c) lower toxicity to plants and animals9; and d) reduced exhaust emissions10.

Biodiesel is also: e) simple to phase in and out of use; f) a local renewable source of

energy; and g) highly biodegradable. Biodiesel also improves the quality of the

environment with a pleasant fruity odour and with less (and far less toxic) soot generated

in the exhaust of vehicles using it. Biodiesel has marine application10 and can also be

used in domestic and commercial boilers11. The most significant downsides of biodiesel

for use in vehicles are a greater affinity for water (due to the polar CO2 group), a greater

tendency to grow micro-organisms, and to go cloudy or set solid at low ambient

temperatures (i.e. at less than ca. 10 °C). Though the latter is clearly more of an issue in

temperate climates than in the tropical South Pacific.

Blends of biodiesel and petrodiesel have been adopted to help lower ‘greenhouse

emissions’5,12. Blended fuel is denoted as BXX, where XX denotes the percentage of

biodiesel by vol%; e.g. B20 indicates a blend of 20% of biodiesel and 80% of petro-diesel

by volume. The most popular biodiesel blend used in the United States is B20 which was

accepted by Congress in 1998 as an Environmental Pollution Act for the USA5.


6

1.2 AIMS

The goals for this project were:

i. A literature study on bio-diesel production technologies, standards and

measurements (Chapter 2);

ii. To identify potential vegetable oil raw materials by assessing availability in

Fiji (Chapter 3) and suitability for producing quality bio-diesel in a local

context by examining their physical and chemical properties;

iii. To produce bio-diesel through transesterification by using the most suitable

oil available in Fiji (Chapter 4);

iv. A detailed examination of the chemical and physical properties of the bio-

diesel produced (Chapter 5); and

v. To document procedures to produce bio-diesel with the available equipment.

Chapter 2: Literature Review and Background

7

2 CHAPTER 2: LITERATURE REVIEW AND

BACKGROUND

2.1 HISTORY

In Rudolph Diesel’s 1893 paper "The Theory and Construction of a Rational Heat

Engine", the German inventor described a revolutionary engine in which air would be

compressed by a piston to a very high pressure thereby causing a sufficiently high

temperature to ignite non volatile oils (that is, to achieve compression ignition, CI, rather

than spark ignition, SI). His first working engine could run on various vegetable oils,

leading him to envision in 1911 that “the diesel engine can be fed with vegetable oils and

will help considerably in the development of the agriculture of the countries that use it”.

However, contrary to Mr. Diesel’s focus on vegetable oils, most CI engines since then

have run on petrodiesel and nearly all research has focused on how to improve the

performance and efficiency of engines using petroleum based fuel. Petrodiesel is safer to

store and transport than petrol, and CI diesel engines are both more robust and more

efficient (> 20% at high load) than SI petroleum engines. These advantages are reflected

in over seven percent of all crude oil being refined to diesel.

Many attempts have been made over the last century to use vegetable oils in CI engines

both in vehicles and for power generation. These have met with limited success, however,

since long term usage of straight vegetable oil causes problems like gumming and


8

deposits in the engine due to polymerization of vegetable oil. The combination of the

high viscosity and low volatility of vegetable oil caused delayed ignition and hampering

of engines. The relatively high freezing points and viscosities of vegetable oil limit their

use in cold conditions. However, with a few relatively simple modifications (such as fuel

preheating and altered engine timing), a standard CI engine can be made to run more-or-

less reliably and efficiently on vegetable oils such as coconut- or waste oils from food

industry (attempts to apply this strategy in the Pacific region are surveyed below).

Table 2.1 Diesel Substitutes Made From or Based on Vegetable Oil 13

Method Description Properties of fuel.

Pyrolysis

Thermal decomposition of triglycerides

affords, alkanes. Alkenes, alkadienes,

aromatic and carboxylic acids.

Low viscosity and high cetane

number compare to vegetable oil.

Acceptable amount of sulfur,

water and sediments.

Unacceptable ash carbon residue

and pour point.

Microemulsion

Stable dispersion of vegetable oil with

an ester and dispersant (cosolvent) or

of vegetable oil, an alcohol and

surfactant with or without diesel fuel.

The droplet diameter in a

microemulsion ranges from 100 Å -

1000 Å.

Reduced viscosity and nozzle

choking of the engine. But carbon

deposits on the injector nozzle

and exhaust valves.

Dilution

Vegetable oil diluted with diesel fuel or

solvent such as ethanol, paraffin and

naphthalene.

Reduced viscosity, heavy carbon

deposits causing nozzle choking.

Not appropriate for long term use

due to thickening of lubricants.

Transesterification

Chemical modification of edible oils

using methanol or ethanol to produce

methyl or ethyl fatty-acid esters.

Very similar or better properties

than diesel, rendering it the most

likely substitute for diesel fuel.


9

Attempts have also been made to modify the properties of vegetable oil fuel for use in

unmodified CI engines.

Here the physical properties of the fuel are altered and optimized for use in standard

diesel engines. The main methods devised for this purpose involve pyrolysis, dilution

and/or chemical modification (see Table 2.1). The latter is the only fuel modification

method so-far devised that produces a liquid with essentially the same fuel properties as

petrodiesel (see Table 2.2 and compare Figure 1.2).

Table 2.2 Fuel Properties of Biodiesel Compared to Conventional Diesel Fuel.

Fuel properties Soybean Methyl Ester

(B100)8

Petrodiesel

Viscosity (mm2/s) 4.41 (at 40 ºC) 38SSU14

Cetane number 48.2 40 – 5615

Flash Point (ºC) 174 5614

Cloud Point (ºC) 1 -314

Pour Point (ºC) -4 -1216

2.2 GLOBAL PERSPECTIVE AND BIODIESEL STANDARDS

The introduction of a biodiesel industry has reduced an unhealthy reliance on foreign

fossil fuel in many countries around the world including Europe, Africa, America, Asia

and the Pacific. The increasing usage, as well as research and production interest in this

field, has spurred the need to have standards for biodiesel fuel. Standardisation of

biodiesel is essential for its marketing and commercialisation. Specifications are

necessary for authorities to maintain the homogenous quality of the biodiesel fuel. Also,

there is a need to guarantee the safety and environmental credentials of the product.


10

The standards for biodiesel in Europe are set by the European Committee for

Standardization (CEN), of which many European countries are members. However, each

of these countries has its own biodiesel standards tailored to the climate and raw material

availability (Table 2.3). The result is a standard of acceptable levels for the chemical and

physical properties of biodiesel fuel.

Table 2.3 Biodiesel Fuel Standards in Europe Countries.

Europe Country Biodiesel Fuel Standard Protocol Used

Austria Austria Biodiesel Standards ON or ONORM

Czech Republic Czech Republic Biodiesel Standards CSN

European Union European Union Biodiesel Standards prEN

France France Biodiesel Standards Journal Officel

Germany German Biodiesel Standards DIN

Sweden Sweden Biodiesel Standards SS

Italy Italy Biodiesel Standards UNI

Biodiesel is made from several alternative edible oils and is referred to by various names,

including: Rapeseed Oil Methyl Ester (ROME), Fatty Acid MonoAlkyl Ester (FAMAE),

Fatty Acid Methyl Ester (FAME) and Vegetable Oil Methyl Ester (VOME) in Europe.

Coconut biodiesel (coconut oil methyl ester) is conveniently referred to as COCOHOL

(cf. Table 2.5 below).

In the USA and Canada (which use the ASTM D6951standard) biodiesel production is

encouraged by a tax incentives scheme which lowers the cost of biodiesel at the pump17

Other, countries such as Brazil, Korea, Japan and Argentina has modified the European

and ASTM biodiesel fuel standards to make them suitable for their climate, environment


11

and consumer demands. In the Pacific region, Australia has specifications gazetted under

Section 21 of the Fuel Quality Standard Act 2000 (see Table 2.4)

Table 2.4 Fuel Standards for Biodiesel in Australia 18.

Property Testing Method Limits Units

Acid number ASTM D 664 0.80 max mg KOH/g

Alcohol prEN 14110 0.20 %m/m

Carbon Residue 10% EN ISO 10370 0.30 %mass

100% ASTM D4530 0.05 %mass

Cetane Number EN ISO 5165 or ASTM D613 51 min

Contamination (total) EN 12662 or ASTM 5452 24 max mg/kg

Copper Strip Corrosion (3hrs @ 50°C)

ASTM D130 No. 3 max

Density @ 15°C ASTM D1298 or EN ISO 3675 860-890 kg/m3

Distillation 90ºC ASTM D160 360 max ºC

Ester Content prEN 14103 96.5 min %m/m

Flash Point ASTM D93 120 min ºC

Glycerol Free ASTM D6584 0.020 max % mass

Glycerol Total ASTM D6584 0.250 max % mass

Metal Group I (Na, K) prEN 14108 & prEN 14109 5 mg/kg

Metal Group I (Ca, Mg) prEN 14538 5 mg/kg

Oxidation Stability (6hrs) PrEN 14112 or ASTM

D2274 (per biodiesel) 110 ºC

Phosphorus ASTM D4951 10 mg/kg

Sulfur ASTM D5453 10 mg/kg

Sulfate Ash ASTM D874 0.02 % mass

Viscosity 40°C ASTM D445 3.5-5.0 mm2

/s Water and Sediment ASTM D2709 0.05 % vol

a) ASTM followed by an alphanumeric code means the testing method developed by ASTM

International under the alphanumeric code; and b) prEN, EN and ISO EN followed by number means that the testing method developed by the

European committee for Standardisation (CEN) under the code number.


12

2.3 REGIONAL PERSPECTIVE AND PRODUCTION

Copra from coconuts is a major agricultural crop in the Pacific region. It was once an

important export for Fiji. The demand for this crop from Pacific Island countries has

fallen markedly, thus affecting revenue earned through export and forcing countries to

venture into other industries to survive. Since it is endogenous, abundant in supply, and

with a perfect climate for production, this crop has been explored widely as a biofuel in

the region. A survey carried out by Pacific Islands Applied Geoscience Commission

(SOPAC) has studied the potential of domestic coconut oil as a source of renewable

energy. It confirms that a “large potential exists” (Figure 2.1)19.

Figure 2.1. Coconut Oil Production Potential and Exports of Pacific Island Countries19.

17.47

3.06 3.44

53.91

10.927.1

0 0.29

30.51

0

10

20

30

40

50

60

Am

ount

of C

ocon

ut O

il (M

illio

n Li

ters

)

Fiji Isl

ands

Kiribat

i

Mars

hal Is

land

s

Papua

New Guin

ea

Samoa

Solomon

Islan

ds

Tonga

Tuvalu

Vanuat

u

Pacific Island Countries

Coconut Oil Production and Exports in the Pacific Islands


13

Coconut oil has been reported as a source of fuel and/or additive in fuel mixtures in the

early 1980s in Fiji. Because of the abundance of coconuts in the region and because of its

physical and chemical properties, coconut oil and mixtures containing coconut oil and

coconut oil derivatives are being actively investigated.

Table 2.5 Coconut oil, Mixtures and Derivatives as Fuel in the Pacific.

Biofuel Aim of Investigation Methodology Findings • Neat esterified

coconut oil (COCOHOL)

• Mixture of COCOHOL and Kerosene.

Suitability of esterified coconut oil as fuel substitute in kerosene hurricane lamps

Hurricane lamps fuel with respective biofuel were lit and observed. The luminosity of the flame and the wick length was measure after intervals.

Mixtures of COCOHOL and kerosene were acceptable substitutes for fuel in the lamps, with 10% COCOHOL mix performing as well as Kerosene 20.

• Coconut oil ethyl ester

The efficiency of ethyl esters as a substitute for petroleum fuel in domestic lamps and stoves was investigated

The combustion efficiency of ethyl ester and kerosene fuel was compared.

Coconut oil ethyl esters are as equally efficient as petroleum fuel for providing energy for domestic cooking and lightening in rural Pacific Island nations 21.

• Coconut oil • COCOHOL

esterified coconut oil

The performance of both coconut oil and esterified coconut oil COCOHOL as fuel was investigated on diesel engines.

The miscibility of each fuel with diesel oil was studied together with the thermal efficiency of fuel with engine loading.

• Coconut oil was found to be immiscible with diesel oil with decreasing efficiency with high engine loading. As a fuel coconut oil was found to be problematic during low temperatures.

• COCOHOL was miscible with diesel oil, ethanol and coconut oil. COCOHOL and ethanol blended fuel was observed to be as efficient as diesel oil even at high engine load. Less cylinder choking and exhaust smoke was reported 22.

• Coconut oil Specific fuel consumption

and contamination of fuel due to engine wear was studied using different fuel.

Coconut oil was blended with distillate diesel fuel and compare with results from using diesel fuel in engines.

Fuel containing coconut oil blend appeared to show reduced engine wear indicated by metal contamination in fuel 23.


14

Research on the efficiency of coconut oil and its derivatives as biofuel has been carried

out previously in Fiji20-23. However, the sources of coconut oil derivatives and methods of

production were not specified. The quality of the derivatized product was also not

examined, implying inconsistency in the engine efficiency results obtained from these

biofuels.

More recent energy-resource studies in Fiji have expanded the information on coconut oil

as biofuel. An joint initiative by Fiji Government, Department of Energy and SOPAC has

calculated that the total energy available from local coconuts is sufficient to cater for the

energy need of rural villages in Taveuni and Vanua Balavu. These projects have attracted

the support of the French Government and SPC-CIRAD24.

Figure 2.2 Biodiesel Batch Process Plant at Lami.

This plant was set up in 1982 for small batch process biodiesel production from coconut oil in Fiji.


15

Research on liquid biofuels in Pacific Island countries has shown that most island nations

could use coconut oil to supplement their energy requirements either in form of blended

mixtures or neat oil. Coconut oil produced in these island countries has a retail price

comparable with diesel or (esp. in recent times) considerably lower. Biofuel has become a

commercial product in the Solomon Islands, Papua New Guinea and Vanuatu. In

Vanuatu, “Island Fuel 80” is retailed at US$0.30 less than conventional diesel fuel. Island

Fuel 80 is a blend of 80% coconut oil and 20% kerosene that was trialed and optimized

for several years in the Port Vila Toyota dealership with excellent results for vehicle

maintenance and running costs before being up-scaled for commercial use. Following the

success of blended biofuel in Vanuatu, Samoa and the Solomon Islands have taken

initiatives to implement it in their countries. Blends of coconut oil with diesel have been

tested on government vehicles in Kiribati, while coconut oil has been used unsuccessfully

as fuel in diesel engines in the Marshal Islands19.

Of relevance to the local situation, there is a good deal of information about the

production and use of bio-diesel in the Philippines and Hawaii to draw upon; including

low-tech methods of producing coconut biodiesel and used-cooking-oil biodiesel in

isolated centers. Both countries have established commercial plants for mass production

and operate commercially, encouraging the use of biodiesel as an alternative renewable

energy fuel.


16

There is therefore an expanding need to research and establish a protocol for biodiesel

production and its quality control specifying appropriate standardisation in order to

generate a consistent sustainable renewable fuel with similar benefits.

2.4 ENVIRONMENTAL BENEFITS OF BIODIESEL

Concern about the health and environmental effects of diesel has played a major role in

spurring the recent upsurge of interest in biodiesel. Diesel exhaust is very toxic: it is a

known cause of lung cancer25 and more recently a strong link with heart disease has been

established26. Diesel soot contains polycyclic aromatic hydrocarbons (PAH) such as, (a)

pyrene, (b) benzo(a)pyrene and (c) nitropyrene which being lipophilic and slow to

metabolize are accumulated by humans (see Fig. 2.3).

Figure 2.3 Some PAHs Emitted from Diesel Exhaust

Not only these compounds (formed via incomplete burning of diesel) known to cause

adverse health effect to humans but the PAH’s in diesel soot may also react with OH and

a) pyrene

b) benzo(a)pyrene

NO2

c) Nitropyrene


17

NO3 radicals in the atmosphere to produce substances that have an even greater

mutagenic and carcinogenic property than the original hydrocarbons27.

The burning of diesel is a major contributor to the global man-made carbon dioxide

production that (according to a consensus of scientists) is responsible for a net global

warming effect that contributes to worsening environmental problems like intense storms

and rising sea levels. Atmospheric carbon dioxide concentration has increased over the

last decade at an alarming rate of 1.6ppm per year28. Biodiesel is derived mainly from

‘living carbon’ rather than fossil carbon. For living carbon, as much carbon is absorbed

from the atmosphere during its formation (in vegetable matter) as is released when it is

burned. This makes biodiesel as a renewable and sustainable energy resource; a resource

that is an integral part of the “Green Revolution Solution” to make the global

environment cleaner and safer to live in.

Notable quote: "In May 2000, bio-diesel became the only alternative fuel to successfully

complete the Environmental Protection Agency's Tier I and Tier II testing under Section

211 (b) of the Clean Air Act. The Department of Energy and the U.S. Department of

Agriculture have calculated carbon dioxide reductions of 78 percent for bio-diesel when

compared with petroleum diesel in a full life cycle analysis. Bio-diesel also reduces air

pollutants linked to cancer by 80-90 percent vs. petroleum diesel”29

Biodiesel fuel is essentially harmless to humans; indeed, France classifies biodiesel as a

‘food’ in its regulations pertaining to the transport of hazardous materials. The vapor is

non-poisonous and non-intoxicating to breathe (or even to ingest in small quantities),

whereas petroleum fuels contain aromatic compounds - such as benzene, xylene and


18

toluene - known to be acutely toxic as well as carcinogenic. When biodiesel is burned in a

diesel engine it produces less emissions and those emissions that are less toxic than for

petrodiesel. The methyl and ethyl esters of fatty acids are partially oxygenated

hydrocarbons; the CO2 groups contained in their structures improve combustion

efficiency, resulting in cleaner exhaust, less soot formation and lower carbon monoxide

emissions10. Moreover, any unburned fuel contained in the exhaust is less toxic for this

biofuel than for fossil fuel (see above). Unlike petrodiesel, biodiesel is naturally

lubricating (has a high ‘lubricity’) eliminating the need for sulfur-containing additives; it

therefore displays a 100% reduction in sulfur emission. This is significant because sulfate

in emissions generates sulfuric acid causing corrosive acid rain.

Table 2.6 Emission Change in Biodiesel and Blended Biodiesel Fuel5.

Neat Biodiesel (B100)* Blended Biodiesel (B20)**

Carbon Monoxide (CO) -43.2% -12.6%

Hydrocarbons (HC) -56.3% -11.0%

Particulate Matter (PM) -55.4% -18.0%

Nitrogen Oxides (NOx) +5.8% +1.2%

Air toxics -60% to –90% -12% to –20%

Mutagenicity -80% to –90% -20%

Carbon dioxide*** -78.3% -15.7%

*Average of data from 14 EPA FTP Heavy Duty Test Cycle tests, variety of stock engines **Average of data from 14 EPA FTP Heavy Duty Cycle tests, variety of stock engines ***Life cycle emissions

Toxic emissions. As shown in Table 2.6, biodiesel or its diesel blend B20 is much better

for the environment than petrodiesel, with a small (6%) increase in NOx production more

than offset by large reductions in toxic and particulate emissions.


19

Carbon dioxide. The use of plant-based renewable raw materials to produce biodiesel fuel

aids in recycling carbon dioxide emitted from vehicles: the carbon dioxide is derived

from plants and is absorbed back into the plants that are the raw material for biodiesel

production. Unlike the more controversial situation with cultivated crops (for which large

amounts of fossil-carbon-derived energy is expended in tilling, fertilizing, harvesting and

transport)30 biodiesel fuel from free-growing tropical crops like coconut qualifies as a

carbon neutral product.

Ozone. Emissions from ethanol-gasoline mixtures (in particular, the E85 or 85% ethanol

+ 15% gasoline mixture) contain formaldehyde and acetaldehyde, which have been

reported to increase ozone-related mortality and hospitalization compared to emissions

from fossil gasoline31. By contrast, the emissions from neat biodiesel significantly reduce

production of ozone-forming hydrocarbons.32

Biodegradation. Biodiesel undergoes rapid degradation by microbes in both terrestrial

and in aquatic environments33. Blended biodiesel is degraded more rapidly than pure

petrodiesel in the environment. Indeed, the addition of vegetable oil (or biodiesel) to

diesel or crude oil spills on water leads to accelerated biodegradation and clean-up. This

is an important attribute for sensitive coral-reef and small-island habitats as any fuel spills

that might occur would be relatively harmless to humans, plants and animals.

The next chapter investigates the raw materials available in Fiji for biodiesel production.

It identifies the most suitable lipid source through a series of chemical and physical


20

analysis. To determine the synthetic pathway of biodiesel as final product, the quality of

the lipid source is essential to obtain

Chapter 3 Raw Materials – Feedstock Availability and Analysis

21

3 CHAPTER 3 – RAW MATERIALS – FEEDSTOCK

AVAILABILITY AND ANALYSIS

3.1 INTRODUCTION

Raw materials for biodiesel production need to be selected according to their

availability and cost in the country or region. Economic feasibility studies of large-

scale production of vegetable oil-derived fuel have indicated that the raw materials

contribute 85-95% of the total production cost34. The production cost of biodiesel

depends mainly on feedstock cost even when there are low conversion yields35. This

underscores the importance of selecting the appropriate feedstock in a sustainable

biodiesel production process.

Equally important is the quality of raw materials used for production of biodiesel fuel.

Raw materials generally need to undergo treatment to upgrade the source materials to

acceptable quality. The chemical composition and the physical properties of source

materials affect both the production efficiency and the performance of the final

product. Chemical properties including free fatty acid content, phosphorus content

and iodine value determine the suitability of the lipid feedstock. Physical properties

such as moisture content and viscosity are also important for the production process.

A third consideration is the energy required to produce the oil. This includes energy

for cultivating, harvesting and extracting the lipid from the crop. For free-growing

lipid sources the energy overheads are smaller but we still need to consider labour


22

energy, facility energy and transportation energy. These energy factors need to be

minimised in order to gain a maximum benefit of biodiesel as an alternative fuel.

This chapter reports the first phase of my research project in which suitable biodiesel

lipid feedstocks were identified and the quality of local raw materials was

experimentally examined. This data-gathering phase of the work was done with the

assistance of survey reports and regional studies made available by SOPAC and

gathered while on secondment at their Mead Road offices. The method development

and the analysis were performed in the Chemistry Department of the USP.


23

3.2 IDENTIFYING & SURVEYING EDIBLE OIL

FEEDSTOCKS.

3.2.1 Lipid source material

The bulk of the energy in the lipids of plants and animals is held in the glycerol-based

fats and oils.

Figure 3.1 Lipid Classes and Some Fatty Acids and Found in Edible Oils.

H2C

CH

H2C

O

O

C

O

R

C

O

R

OCR

O CO

OH

oleic acid (C18:1)

Free Fatty Acid, FFA RCO2H =

C

O

OH

lauric acid (C12:0)

C

O

OHmyristic acid (C14:0)

triglyceride (TG)

H2C

CH

H2C

O

OH

C

O

R

OCR

O

diglyceride (DG)

H2C

CH

H2C

OH

OH

OCR

O

monoglyceride (MG)

H2C

CH

H2C

OH

OH

HO

glycerol (G)

C

O

OH

linoleic acid (C18:2)

C

O

OH

palmitic acid (C16:0)

CO

OH

LIPID CLASSES SOME FATTY ACIDS IN EDIBLE OILS

arachidonic acid (C20:4)

major FA in canola& soyabean oil& hence 'waste oil'

polyunsaturated FA (PUFA) in sunflower oil& safflower oil

major FA in palm oil (esp. in palm fat)

an omega-6 fatty acid found in meat & egg yolk; cf. linolenic acid (C20:3), an omega-3 FA in fish oil.

major fatty acids in coconut oil

ω−13

6


24

Triglycerides (TG) along with varying smaller amounts of diglycerides (DG),

monoglycerides (MG) and free fatty acids (FFAs) make up the typical composition of

an oil or fat (see Fig. 3.1, noting that DG and MG are actually random mixtures of

positional isomers of the indicated glyceryl esters).

Early research in biodiesel production indicated that soybean oil, rapeseed oil and

sunflower oil were suitable lipid feedstocks. They met the criteria:

“To be a viable substitute for a fossil fuel, an alternative fuel should not only have

superior environmental benefits over the fossil fuel it displaces, be economically

competitive with it, and to be reproducible in sufficient quantities to make meaningful

impacts on energy demands, but it should also provide a net energy gain over the

energy sources used to produce it”30.

However, feasibility and sustainability assessments have pointed out problems with

this strategy; that the use of new oil from cultivated crops would detract from food

supplies and that it would be better to use low-grade or waste oil for biodiesel

production since an added demand for edible oil would drive up food prices. It was

found that biodiesel of similar quality and engine performance could be guaranteed

using a feedstock that is non-edible.

Suitable Feedstocks. The feedstock oil is made up of glycerides with varying fatty-

acid chain lengths and saturation (see Figure 3.1 for some examples). The fatty acid

composition of the oil is reflected in the properties of the final derivatized fuel, which

is simply the corresponding mixture of methyl (or ethyl) esters of the fatty acids

present in the glycerol lipid (cf. Figs 1.1 & 1.2).


25

Most vegetable and animal oils and fats (TGs) give alkyl esters that are satisfactory

(in terms of viscosity, energy content, cetane rating etc.) as substitutes for petrodiesel.

However, long-chain saturated fatty acid esters tend to have too high a melting point;

e.g. pure methyl stearate, Me18:0, has melts at 38 °C, precluding the use of (say)

methyl “beef tallow biodiesel” as a major component of pure or blended biodiesel.

While biodiesels made from highly unsaturated oils (as in high-PUFA oils from

safflower and linseed, e.g.) tend to undergo rapid and extensive autoxidation reactions.

C

CO

OMe

methyl linolenate in, say, fish oil- or flax oil biodiesel

H

H

HH

especially weak C-H bonds - undergo rapid autoxidation

ω−3

Autoxidation is the slow spontaneous reaction with oxygen. The weakest bonds in a

molecule participate most readily. PUFA oils and their derivatives have large concentrations

of the “bisallylic methylene” groups indicated above. The first stage is a free-radical reaction

that inserts molecular oxygen (from air) into these CH bonds..

C

H H

C

H O OH

lipid lipid hydroperoxide

O2 (from air), radical catalyzed

peroxidation

This peroxidation step results in a cascade of further reactions of the hydroperoxides

(including cyclization, cross-linking, polymerization, β-scission and condensation reactions)

that leads to oxygen-lipid co-polymers (cf. setting of linseed oil varnish) and formation in lipid

biofuel of gums and gels. – See, e.g.36

Thus, provided the freezing point is not too high, a more stable – longer shelf-life –

biodiesel can be made from mainly saturated oils like coconut and palm oils than from


26

high-PUFA oils like sunflower. Mainly mono-unsaturated oils like soybean and

canola oils (containing mainly oleic acid) afford biodiesels that are somewhat

oxidizable but with lower freeze & cloud points suitable for cooler climates.

A survey of the literature shows that biodiesel production typically uses several edible

oils that are also agricultural crops. These include: soybean oil37,38, rapeseed oil39,38,

corn oil40, coconut (copra)oil, palm kernel oil41, palm oil42, canola oil43,38, olive oil44,

sunflower oil45,46,47, hazelnut oil47, linseed oil48 , safflower oil48, castor oil49, fish oil50,

rice bran oil51, cotton seed, poppy seed oil40, nut sedge oil52, and Camelina oil

(Camelina sativa)43. Alternative lipid sources derived from food material not fit for

consumption include low grade salmon oil54 and heat damaged canola oil seeds55.

Non-edible lipids. These have been a recent “hot topic” for researchers who have

endeavoured to find organisms with high lipid content that is suitable for biodiesel

production. Azam et al, (2005)56 examined the fatty acid methyl esters of 75 oil-seed

and kernel-plant species and evaluated their use as biodiesel fuel. Fatty acid methyl

esters of 37 of the plant species studied were found to comply with major biodiesel

specifications of USA, Germany and the European Standard Organisation. The non-

edible plants species that can survive in marginal, non-cropped land included:

Jatropha (Jatropha curcas)57, Azadirachta indica, Calophyllum inophyllum, and

Pongamia pinnata. Other non-edible plant seeds that have been investigated as a lipid

raw material for biodiesel production are tobacco (Nicotiana tabacum. L)58, Mahua

(Madhuca indica) 59, Karanja (Pongamia glabra)60 and rubber seed oil61


27

Waste Oil. Used frying oil or waste oil is inferior in quality to fresh vegetable oil.

Being cheap or even free, however, it is a popular raw material for biodiesel

production62,63,64,43, especially for medium, small and ‘backyard’ operations. The

composition of used frying oil is complicated by its history of interaction between the

frying oil and the food material being fried. Some of the lipids from the frying food

become mixed with the frying oil, which will therefore often contain chicken and/or

beef fat. Thermal, oxidative and hydrolytic reactions occur during the frying process

resulting in formation of free radical products (see above), Schiff-base addition

products and volatile compounds like amides, acid nitriles, alkyl pyridines and

pyrroles65. All these induce physical and chemical changes to the oil such as increased

free fatty acid content, and viscosity, decreased iodine value, development of darker

colour and change in refractive index.

As with used frying oil62,66,67, tallow, lard37, meat bone meal68 and animal fat all have

naturally high free fatty-acids content. Canakci et al (2003)35 have conveniently

divided these feedstocks into yellow grease and brown grease relative to their free

fatty acid content of 9% max and 40% max, respectively. A two step synthesis

process resulting is 91% product yield has been reported for brown grease, showing

that even highly degraded frying fats and oils are viable for making biodiesel.

Lipids as raw materials have also been sourced from soap stock69,70 a by-product of

edible oil and rendered fat refining. Lipid filtered out from municipal sewage sludge71

has been explored as raw material for biodiesel production. The microbial algae72,73

Chlorella protothecoids, has been found to contain 55% of an crude lipid (mainly


28

composed of oleic acid and linoleic acid) that can be extracted and transesterified

using acid catalyst (see below) to produce biodiesel.

3.2.2 Alcohol as raw material

The most common type of alcohol used for transesterification is methanol due to its

ready availability and ease of use. Industrially, methanol is made in vast quantities

from natural gas via high temperature catalytic processes.

CH4 + H2O → CO + 3 H2 (Ni cat., 10-20 atm, 850 °C)

CO + 2 H2 → CH3OH (Cu-Zn-alumina cat., 50-100 atm., 250 °C)

Methanol is therefore quite cheap as a starting point for production of fuels and has a

comparatively small carbon footprint (since methane contains only one fossil carbon

per molecule). Methanol is principally used to make formaldehyde (for further

synthesis), to make fuel additives (like methyl t-butyl ether) and, increasingly, for the

production of biodiesel. However, in colder climates methyl biodiesels may have

unacceptably high melting points and cloud points. Biodiesels made with longer

alcohol chains (with ethanol, propanol etc.) have lower melting point/cloud points

than the corresponding methyl esters.

Ethanol. Ethyl alcohol offers an attractive alternative to methanol because ethanol is

less toxic and it is derived from a renewable energy source (from sugars made from

sugar cane, cassava etc.) that might be locally produced rather than imported. One

problem with ethanol is water: ethanol forms an azeotrope with water (96:4

ethanol/H2O) so it cannot be dried for biodiesel production – where it must be dry so


29

as not to inactivate the catalyst - using simple distillation (unlike methanol) (this is

also a hurdle to local production of dry ethanol as a petrol additive). Another problem

with ethanol (reported elsewhere and confirmed in this work) is that it tends to form

an emulsion after transesterification of oil, making separation of ester and glycerol

difficult. Mixtures of methanol and ethanol have been used to improve the solvent

properties and improve equilibrium conversion rate of esters74. Other alkyl alcohols

like t-butyl-, n-butyl-, n-propyl- and iso-propyl alcohols {(CH3)3COH,

CH3CH2CH2CH2OH, CH3CH2CH2OH, and (CH3)2CHOH} have been investigated as

raw materials for biodiesel production75. Of these, isopropyl alcohol (2-propanol) is

the cheapest but shares the ecological disadvantage of the others of being derived

from fossil oil.

Non-catalyzed Biodiesel Formation. Under supercritical treatment, alcohol is

subjected to supercritical temperature and pressure. Supercritical fluids have

thermophysical properties (such as dielectric constant, viscosity, specific gravity and

polarity) that are markedly different from the non supercritical solvents they are

produced from. Methanol has a critical temperature and pressure of 512.2K (239 °C)

and 8.1MPa (8,000 atm.!) respectively76. Reaction conditions can get as extreme as

350 ºC and 20-50MPa. The use of supercritical methanol as a reactant in biodiesel

production process vastly improves the ester formation efficiency, with yields as high

as 95% obtained in 10 minutes76. Supercritical alcohol can even be used with lipid

sources containing high free fatty acid content, without any pre-treatment process

being required. Little or no catalyst is required for the transesterification process

yielding high purity biodiesel. It is clear, however, that this non catalytic process is


30

not economically viable outside a major industrial complex, as reaction conditions are

very drastic.

3.2.3 Catalysts

There are several advantages and disadvantages of the various types of catalyst that

have been used in the biodiesel production. Recent research has focussed on

developing efficient and economically viable catalysts for biodiesel production.

Table 3.1 Comparisons Between Alkaline and Acidic Catalyst

Alkaline Catalyst

Advantages Disadvantages

• Higher conversion rate (4,000 times

faster) of esters under mild conditions

as compared to same amount of acid

catalyst equivalent.

• Smaller amounts are required

compared to acid catalysis.

• Compatible or less corrosive to

industrial equipment as compared to

acid catalysis. Normal carbon steel

based reactor materials can be used

• Alkali catalyst has limited usage with

low-grade lipid raw material. It gets

neutralized (destroyed) in the presence

of high free fatty acids in oil. This is

usually overcome by introducing a pre-

treatment process before

transesterification, which is an added

cost factor in biodiesel production

process.

Acid Catalyst

Advantages Disadvantages

• Can also be used with low grade oil

having high free fatty acids as acidic

catalyst would still be effective.

• Requires drastic reaction conditions

involving high temperature and

pressure for transesterification, making

it dangerous to work with.

Homogeneous alkaline catalysts include alkali metals, alkali metal alcoholates and

hydroxides, aqueous metal hydroxide solutions and strong organic bases.


31

Heterogeneous alkaline catalysts include alkali-metal hydrogen carbonates, alkali-

metal oxides, alkaline-earth metal alcoholates, alkaline-earth metal oxides, alkaline-

earth metal hydroxides, strong anion exchange resins and alkali metal and alkaline

earth metal carbonates and salts of carboxylic acids. Homogenous acid catalysts

include mineral acids, aliphatic and aromatic sulfonic acids, as well as lipid-soluble

lewis acids like InI3. Strong cation exchange resin and metal phosphates are some of

the heterogenous acid catalyst77 that have been investigated. Transition metals and

silicated compounds have also been tried. Enzymatic catalysis process has been

applied to the transesterification of biodiesel, although, to date78, there are no

commercially viable processes based on enzymatic catalysts.

Summary

There are strong environmental, health, economic and energy-cost arguments for the

production and use of vegetable oils as a substitute for petrodiesel, especially in

regions that can utilize ‘free-growing’ feedstocks like coconut oil. Its net energy

balance (NEB) is overwhelmingly (93%) positive compared to other biofuels like

ethanol (25%)30. This means that biodiesel yields 93% more energy than the energy

required for its production and processing. Renewable energy that are non food based

or from waste biomass and benefit positively to environment could provide for much

greater supplies and have merit for being available at a cheaper cost.


32

3.3 METHODOLOGY: ANALYSIS OF RAW MATERIALS

In this study, commercial oil samples and used vegetable cooking oil (waste oil)

were collected using the sampling methodology described below. The method was

designed to get a representative sampling of the whole population of each type of oil.

Each sample was later analysed for it chemical (free fatty acid content, iodine value

and phosphorous content) and physical (moisture content) properties (Figure 3.1).

This quality control protocol indicates the quality of the lipid source and suggests

which synthetic pathway to follow in order to produce quality biodiesel.

Figure 3.2 Chemical and Physical Analysis of Lipid Raw Materials

Fatty acid composition of waste oil (used oil) does not stay same and is not consistent.

In addition to the frying oil itself, fats and oils originating from foods that were fried

in the oil contribute to the fatty acid composition of the used vegetable oil.

FEEDSTOCK

2) Commercial Oil

1) Waste Oil

CHEMICAL ANALYSIS

1) Iodine Value

3) Phosphorous Content

2) Free Fatty Acids

PHYSICAL ANALYSIS

1) Moisture and VolatileMatter


33

Table 3.2 Fatty Acid Composition of Commercial Oil Samples Analysed6.

Fatty acid composition ( wt %)

Oil 12:0

Lauric

Acid

14:0

Myristic

Acid

16:0

Palmitic

Acid

18:0

Stearic Acid

18:1

Oleic Acid

18:2

Linoleic

Acid

18:3

Linolenic

Acid

22:1

Erucic

Acid

Soybean Oil 2.3-11.0 2.4-6.0 49.0-53.0* 22.0-30.8 2.0-10.5

Canola Oil 4.0-5.0 1.0-2.0 55.0-63.0* 20.0-31.0 9.0-10.0 1.0-2.0

Coconut Oil 44.0-51.0* 13.0-18.5 7.5-10.5 1.0-3.0 5.0-8.2 1.0-2.6

* Major fatty acid component of the oil type.

3.3.1 Sampling methods

Commercial oil

The commercial bottled oils collected were soybean oil, canola oil and coconut oil.

The oil samples were refined quality edible oils bought from different supermarkets at

different times to ensure fair representation. There are two dominant commercial

suppliers of vegetable oil in Fiji, bottled oil from each supplier was labelled as brand

one and brand two. Random buying of samples for each brand of oil was carried out

in triplicates.

Waste oil

Waste oil was sampled from three different restaurants and fast food outlets around

Suva. These fast food outlets were chosen as they are reputable and use the same

frying oil in all there branches throughout Fiji.


34

Table 3.3 Lipid Source Before Use from Three Different Outlets.

Used oil Source Original Lipid Before Use Major fat ty acid component

Source 1 Palm shortening Palmitic acid

Source 2 Soybean shortening Oleic acid

Source 3 Soybean oil Oleic acid

Random sampling from each location was carried out in triplicate. The waste oil

samples were collected in acid washed plastic bottles and filtered with cellulose filter

paper to remove small particulate matter originating from food fried in the oil. The

filtered oils were collected and stored in glass bottles at room temperature until

analysed for its chemical and physical properties.

3.3.2 Chemical Analysis

3.3.2.1 Free Fatty Acid (FFA)

(A.O.C.S. Official Method Ca 5a-40)79

The Acid Value is defined as the number of milligrams of potassium hydroxide

required to neutralize 1.0 g of an organic substance. This quantity is related to the free

fatty acid content via the mean molar mass of the fatty acid in the particular oil (mass

% of FFA in the oil).

PROCEDURE

Each oil sample was homogenised by inverting the bottle several times before

weighing out the required amount of oil (see table below) in an Erlenmeyer flask

using an analytical balance. The oil was dissolved in the required volume of

neutralised ethanol. Five drops of phenolphthalein indicator was added, and the


35

magnetically stirred mixture was titrated with 1.0N sodium hydroxide at 60°C to a

pale-pink end point.

Commercial oils were weighed out directly from the bottle. Free fatty acid content

analysis of each type of oil of a particular brand was carried out in triplicates and the

average free fatty acid content was obtained. For each type of commercial oil the

fatty acid was calculated based on the major fatty acid component it contained (Table

3.2 Fatty Acid Composition of Oils Analysed6)

Waste oil that was not liquid at room temperature was heated to melt and cooled

down to room temperature then weighed out. FFA content analysis was carried out in

triplicates and the average value was reported.

Table 3.4 Specifications according to A.O.C.S Ca 5a-40

F.F.A Range (%) Grams of Sample Alcohol (ml) Strength of Alkali

(N)

0.00-0.2 56.4±0.2 50 0.1

0.2-0.1 28.2±0.2 50 0.1

1.0-30.0 7.05±0.05 75 0.25

*30.0-50.0 7.05±0.05 100 0.25-1.0

50.0-100 3.525±.001 100 1.0

*Average % range of lauric acid (major component) in coconut oil.

The mass of sample, alcohol volume and the strength of alkali were determined using

Table 3.4. Calculation of the FFA content depended on the particular oil being tested

as per the following example of coconut oil (44-51% lauric acid).


36

CALCULATION

The percentage of free fatty acids in coconut oil is expressed as lauric acid.

i. Free Fatty acids as lauric,% = vol. of NaOH (ml) x N x 200 x 100%

1000 x Weight of sample (g)

Where:

N = normality of NaOH solution

Use the following constants respectively (Table 3.5):

Constant 200 = molecular weight of lauric acid.

Constant 282 = molecular weight of oleic acid.

Constant 256 = molecular weight of palmitic acid.

ii. Acid Value* = vol. of NaOH (ml) x N x 56.1

Weight of sample (g)

Where:

Acid value = mg of KOH required to neutralise acid in 1 g of sample (as per

definition).

N = normality of NaOH solution

56.1 = molecular weight of KOH

Table 3.5 Free Fatty Acid Values Reported as the Respective Fatty Acid

Oil sample Free fatty acid calculated as

Commercial oil

Soybean oil Oleic Acid

Canola oil Oleic Acid

Coconut oil Lauric Acid

Waste oil

Source 1(a) Palmitic acid

Source 2(b) Oleic acid

Source 3(c) Oleic acid

(a) source 1 used palm shortening for cooking; (b) source 2 used soybean shortening for cooking and (c)

source 3 used soybean oil for cooking

* the FFA% content was calculated as the respective FFA as these fatty acids are major components of

the lipid source.


37

3.3.2.2 Iodine Value (Wijs’ Method)

(A. O. C. S. Official Method Cd 1-25)80

Iodine value measures the level of unsaturation determined by volumetric titration. It

is expressed as the percentage of iodine absorbed by the sample i.e. number of grams

of iodine absorbed by 100g of sample. In the original method an excess of Wijs’

solution (0.2N ICl in CCl4) is added to the oil; the excess ICl is converted to I2 by

adding KI solution and the I2 is then titrated with Na2S2O3 solution. The difference

between a blank titration and the oil containing titration gives the iodine value of the

oil. The original method (Wijs method) was modified according to a publication by

Pocklington, 199081. Modification involved the use of a 1:1 mixture of cyclohexane

and glacial acetic acid as solvent instead of carbon tetrachloride (which is

carcinogenic).

PROCEDURE – SAMPLE AND BLANK PREPARATION

Both commercial oil and waste oil were analysed using the following procedure.

Sample

The recommended mass of homogenised oil sample was added Wij’s solution to an

excess of 50-60% i.e 100-150% of the amount absorbed (Table 3.6). To the sample,

20ml of 1:1 mixture of cyclohexane and glacial acetic acid and 25ml of Wijs solution

(0.2N ICI solution) was added, consecutively. The mixture was stored in the dark for

30 minutes at room temperature. Then, added 20 ml of potassium iodide was added to

the solution followed by 100 ml of distilled water.


38

Table 3.6 Recommended Masses of Sample for Iodine Value.

Sample weight Sample Iodine Value less

than…. 100% excess 150% excess

Coconut oil 20 1.5865 0.8461

Soybean oil 140 0.2266 0.1813

Canola oil 120 0.2644 0.2115

Palm oil 60 0.5288 0.4231

Blank

The blank was prepared by mixing the reagents in same quantity and storing for the

same time under the same conditions as for the sample. That is to say, the same

procedure was used for the blank as for the sample except the oil sample was not

added.

The resulting solution (sample or blank) were titrated with 0.1N sodium thiosulfate

using starch indicator (2 ml). Three trials were done for each sample.

CALCULATION

The iodine value = (B-S) x N x 12.69

Weight of sample

Where:

B = titration of blank

S = titration of sample

N = normality of Na2S2O3 solution.


39

STANDARDISING SODIUM THIOSULPHATE SOLUTION

To 25ml of standard 0.100 N potassium dichromate solution (prepared by dissolving

4.900g in 1.000ι distilled water) in a conical flask, was added 25ml of hydrochloric

acid and 10ml of potassium iodide solution. The solution was swirled then allowed to

stand for 5 minutes before adding 100ml of distilled water and titrating it with sodium

thiosulfate solution until the yellow colour became pale upon which starch indicator

was added and titration continued till the bluish black colour disappeared to form a

colourless mixture. The normality of sodium thiosulphate was calculated using the

following equation.

Normality of Na2S2O3 solution = 2.5

Sodium thiosulfate solution required (ml)

3.3.2.3 Phosphorus Analysis

(A.O.C.S. Official Method Ca 12-55)82

This method involves ashing the oil sample in the presence of zinc oxide followed by

a colorimetric measurement of phosphorous as molybdenum blue. It determines the

phosphorous or the phosphorous equivalent phosphatide content in the oil sample.

PROCEDURE

Both commercial oil and waste oil was analysed using the following procedure.

Glassware treatment.

All glassware used for this analysis were rinsed with distilled water and carefully

soaked in warm 1M HCl solution for 4 hours. Then it was rinsed with fresh distilled


40

water and soaked in 1M HCl water bath for 12 hours before rinsing it with distilled

water and ensuring it is dry ready to use.

Sample (Ashing)

For each oil, a 3.05 ± 0.05g sample was weighed in a Vycor crucible and 0.5g of zinc

oxide was added. The mixture was heated until it thickened and the heat was then

increased to completely char. The sample crucible was then placed in the muffle in

the furnace at 550°C for 2 hours. After cooling to room temperature 5ml of distilled

water was added to the crucible along with 5ml of concentrated hydrochloric acid.

The crucible was covered and gently heated for 5 minutes over a hot plate.

The mixture was filtered into a 100ml volumetric flask and the filter paper was rinsed

with four 5ml hot distilled water washings of the crucible (including the lid). The

filtrate was cooled to room temperature and 50% potassium hydroxide was added to

neutralise the mixture to a slightly faint turbid solution. Upon doing this, zinc oxide

precipitates out of the solution; it was dissolved by adding 2 drops of concentrated

hydrochloric acid to get a clear solution. The solution was then made up to the mark

by adding distilled water and mixing thoroughly.

A 10 ml aliquot of this solution was quickly pipetted out into a clean dry 50 ml

volumetric flask and 8ml of 0.015 % hydrazine sulphate and then 2 ml of sodium

molybdate were added. The mixture was stoppered and inverted several times, then

heated for 10 minutes in a water bath at 100°C. The mixture was cooled to room

temperature (water bath) and finally topped up to the mark with distilled water. It was

mixed and transferred to a clean dry glass cuvette ready for analysis.


41

Blank

The same procedure for sample preparation was followed except no oil sample was

used.

Standards

The volumes that are indicated in Table 3.7 of 0.01mg/ml standard phosphate solution

were pipetted into 50ml volumetric flasks to prepare the corresponding phosphorous

standards.

Table 3.7 Preparation of Phosphorous Standards

Standard Volume pipetted (ml) Phosphorous in standard (mg)

1 0.0 0.000

2 1.0 0.010

3 2.0 0.020

4 4.0 0.040

5 6.0 0.060

6 8.0 0.080

7 10.0 0.100

Each standard was diluted with 10ml of distilled water, then 8ml of hydrazine

sulphate and 2ml of sodium molybdate were added. The resulting mixture was

homogenised and heated in a boiling water bath before cooling and topping up to the

mark and the solution transferred into cuvettes for analysis.

A calibration graph of transmittance against phosphorus content in milligrams was

plotted to compare with the sample aliquots.


42

ANALYSIS

The percentage transmittance of the sample, blank and standards were measured at

650nm using Cintra 5 UV double-beam spectrometer. The cuvette was thoroughly

rinsed with distilled water between analyses to minimise cross-contamination of

samples. Each sample was analysed in triplicate.

CALCULATION

Phosphorus % = 10 (A-B)

WV

Where:

A = phosphorus content of sample aliquot in mg*

B = phosphorus content of blank aliquot in mg*

W = Weight of sample in grams

V = Volume of aliquot = 10ml

* The phosphorus content of the sample and the blank were read from the

transmittance versus concentration calibration graph.

3.3.3 Physical Properties

3.3.3.1 Moisture and Volatile Matter

(A.O.C.S. Official Method Ca 2b-38)83

PROCEDURE

A 20.0 ±0.5 g sample of homogenized oil was weighed into a beaker then cooled and

dried in a desiccator. The beaker was carefully placed over a hot plate at 80 ºC and

heated with occasional swirling and avoiding splashing. The temperature was slowly

increased to 110 ºC and held at this temperature until the steam disappeared. Then

heated for another 10 minutes before cooling to room temperature in a desiccator. The


43

sample was weighed and heated over hot plate and cooling was repeated until a

constant weigh was recorded.

CALCULATION

Moisture and volatile Matter % = loss in weight x 100

Weight of sample


44

3.4 RESULTS AND DISCUSSION

3.4.1 Chemical Analysis of Raw Materials

3.4.1.1 Free Fatty Acid Content.

A large amount of free fatty acid is detrimental to the base-catalytic transesterification

process. Free fatty acid cannot be converted into biodiesel using alkali catalyst, it

reacts with the alkaline catalyst and produces soap that inhibits separation of the

glycerol, biodiesel and water layer before and during purification process. Freedman

et al, 198484, recommends a lipid source with FFA content of less than 0.5% (acid

value of 1) for maximum ester formation via alkali catalytic transesterification. The

results are summarised in Tables 3.8 and 3.9 below.

Table 3.8 Free Fatty Acid Content of Commercial Oil for Biodiesel Synthesis

Range Mean Standard Deviation

FFA (%) AV (mgKOH/g) FFA (%) AV

(mgKOH/g) FFA (%) AV (mgKOH/g)

Soybean Oil 0.1166-0.2141

0.2320-0.4260

0.1538 0.3059 0.0315 0.0626

Canola Oil 0.1558-0.3109

0.3100-0.6184

0.2086 0.4150 0.0496 0.0986

Coconut Oil 3.13-4.33 8.78-12.14 3.72 10.43 0.42 1.18

Table 3.9 Free Fatty Acid Content of Waste Oil for Biodiesel Synthesis


FFA (%) AV (mgKOH/g) FFA (%) AV

(mgKOH/g) FFA (%) AV (mgKOH/g)

Source 1 1.60-12.85

3.51-28.16 6.75 14.79 4.8580 10.6460

Source 2 5.85-12.09

12.83-26.50

9.56 20.96 2.7942 6.1233

Source 3 0.48-0.95 1.05-2.09 0.75 1.65 0.1910 0.4183


45

Two commercial oil samples, namely soybean oil and canola oil have FFA value less

than 1% (see Appendix 1 table A1 and A2). However, coconut oil and waste oil (see

Appendix 1 table A3 and A4) contain higher FFA value exceeding 1% or an acid

value of 2. The FFA and Acid value of waste oil have a high standard deviation

indicating the inconsistency in the quality of oil. This amount is considered high and

is seen as a factor that would affect the final yield of biodiesel.

3.4.1.2 Iodine Value

The density and cetane number of fatty acid esters increase linearly with the iodine

number. Whereas, reducing the iodine value is reported to lead to a reduction in NOx

emissions from biodiesel in diesel engines. Biodiesel with an iodine value of 95 has

been demonstrated to emit NOx gases equivalent to certification fuel mean for

petrodiesel (4.59 g/BHP-hr for NOx)85.

Iodine value is inversely related to the storage capacity of the oil. It is the measure of

the unsaturation of fats and oils and is expressed in terms of the number of centigrams

of iodine absorbed per gram of oil (% iodine absorbed). The lower the iodine value

the longer the time it will take for the oil to oxidise under air. That is, low iodine

value oils can be stored for a longer period of time as compared to oil with high

iodine value. The iodine value of a triglyceride is expected to be be very close to that

of the transesterified product since the process does not destroy the double bond in the

fatty acid chain.

The measured iodine values are given in Appendix 1, Tables A5-A8. The results are

summarised in Tables 3.10 and 3.11


46

Table 3.10 Iodine values of commercial oil samples


Soybean Oil 116.70-134.47 128.40 5.19

Canola Oil 111.02-132.92 119.97 6.55

Coconut Oil 6.08-9.26 7.91 0.83

Table 3.11 Iodine values of waste oil samples


Source 1 46.20-51.47 49.27 1.85

Source 2 39.31-64.82 55.42 1.85

Source 3 40.90-70.03 58.81 10.58

3.4.1.3 Phosphorous content.

Phosphorous compounds are present in oil samples as phosphatides. These

compounds are known to be responsible for “gumminess” of oil. Phosphatides present

in biodiesel fuel promote accumulation of water that degrades its quality. Moreover,

phosphorous compounds in oil react with alkali catalysts to cause a reduction in the

final biodiesel yield84.


47

Figure 3.3 Calibration Graph of Phosphorous Standards

The graph in figure 3.3 was used to determine the:

A- phosphorous content of sample in aliquot (mg)

B- phosphorous content of blank (mg)

Table 3.12 Phosphorous content of commercial oil samples

Range % Mean Standard Deviation

Soybean Oil 0.0003-0.0277 0.0185 0.0131

Canola Oil 0.0001-0.0276 0.0139 0.0140

Coconut oil

Phosphorus content of coconut oil was very low and below significant range and

phosphorous was not detected using this method.

Waste oil

Phosphorus content of waste oil from all three sources was very low and below

significant range and was not detected using this method.

y = -1187.4x + 98.597

R2 = 0.9938

86.00

88.00

90.00

92.00

94.00

96.00

98.00

100.00

0.000 0.002 0.004 0.006 0.008 0.010 0.012

concentration of samples (mg/l)

Tra

nsm

ittan

ce (

%)


48

The phosphorous content of the commercial oil and waste oil were all very low and

insignificant as they have been degummed during refining process and degraded due

to the heat required for cooking. Thus, the phosphorous content in these oils will not

significantly affect the final biodiesel yield.

3.4.2 Physical Analysis of Raw Materials

3.4.2.1 Moisture content

(A.O.C.S. Official Method Ca 2b-38)80

For biodiesel production the raw material needs have minimal moisture content as

moisture causes soap production during the process.

Table 3.13 Moisture Content and Volatile Matter of Commercial Oil Samples


Soybean Oil 0.0179- 0.0862 0.0575 0.0127

Canola Oil 0.0464-0.0837 0.0551 0.0092

Coconut Oil 0.1223-0.4190 0.2854 0.0715

Table 3.14 Moisture Content and Volatile Matter of Waste Oil Samples


Source 1 0.0808-0.3785 0.1562 0.0887

Source 2 0.1416-0.2472 0.1925 0.0377

Source 3 0.1416-0.2472 0.1925 0.0377

The moisture content and volatile matter for all the lipid source (commercial and

waste oil) are comparatively below 1%. The amounts are present in a very low


49

quantity thus saponification during transesterification process due to moisture content

from oil will be low.

3.4.3 Raw Material Used in this Research: Logistics Study

The most significant factors affecting economic feasibility of a continuous biodiesel

production process are the plant capacity and prices of feedstock and biodiesel62. The

starting materials for biodiesel production are the alcohol, the catalyst and the lipid

feedstock. The Pacific region contains developing countries and has limited access to

technological advancement in the chemical reaction field. Thus, the choice of catalyst

and alcohol in the process of transesterification to produce biodiesel fuel will be

mainly determined by what is the cheapest and most readily available. This includes

potassium hydroxide and sodium hydroxide as potential base catalyst used. These

chemicals have wide use for agrochemical and cleaning purposes and are readily

available in local chemical agencies in the regions. Sulfuric acid might be used as an

acid catalyst because it is cheap and readily available.

As far as alcohol is concerned, methanol and ethanol are used in this study. Alcohol is

shipped into the region mainly from Australian chemical companies. Countries like

Fiji Island in the region have great potential to generated ethanol from sugar cane

industry. Fiji Sugar Cooperation are planning to or are researching on expanding and

venturing into ethanol production from baggase (a by product of sugar processing).

Other agricultural biomasses, with high starch content that are available include

cassava and dalo. There is limited range available in selecting the most feasible

catalyst and alcohol as raw material for biodiesel fuel production. In contrast, a


50

variety of lipid feedstocks are widely available consisting of different vegetable oils

both fresh and used oil.

3.4.3.1 Lipid Raw Material

Lipid sources from various origins are available in Fiji. The following criteria were

used to choose the lipid raw material for biodiesel production. The lipid source must

be:

1. in abundance and accessible,

2. affordable,

3. in consistent supply.

The scope was to cover all possible major lipid sources that were available in

abundance in Fiji. The two possible lipid sources that were explored were commercial

oil and waste oil.

Commercial oil

Vegetable oil is imported into the country and sold for cooking ingredients. The

refined edible oils include soybean oil, canola oil, sunflower oil and olive oil. Coconut

oil was considered suitable for biodiesel production in accordance with the criteria

described above. It is used in biodiesel production trials in the next chapter.

COCONUT OIL

Being a local product, coconut oil is the potential target as a main lipid source since it

abundant and in secure supply. There are coconut industry in Fiji comes under the

control of the Coconut Industries Development Authority (CIDA). Their Savusavu

Coconut mill produces most of the coconut oil and its products, in Fiji. As a lipid


51

source, it would contribute to reducing the cost of the lipid derivative ascertained as

the final product in biodiesel production.

SOYBEAN AND CANOLA OIL

Around the world the most common feedstock for biodiesel production are canola

(rapeseed) and soybean oil. In this research, soybean oil and canola oil have been used

as lipid source for reference purposes and to compare the result of analytical analysis

of lipids used.

Waste oil

Used oil from restaurants and fast food industries is an attractive feedstock for

biodiesel production. It can simply be collected and used instead of disposing of it as

waste. While unsuitable for re-use in food, used frying oil is the cheapest raw material

for biodiesel production. It contains very similar lipid constituents as non-used oil,

together with the lipids extracted from the food that is cooked in it making it rather

high in free fatty acids. Though not as abundant in supply as coconut oil, waste oil is a

viable lipid source for biodiesel production in Fiji as it is accessible and affordable.

Biodiesel production using waste oil is discussed in the following chapter.

Chapter 4 Synthesis and Purification

52

4 CHAPTER 4 SYNTHESIS AND PURIFICATION

4.1 INTRODUCTION

Biodiesel can be synthesized through acid-, base- or enzyme-catalyzed

transesterification reaction. Transesterification of lipids produces a mixture of fatty

acid alkyl esters (biodiesel) and glycerol as the by-product. It is a set of three

consecutive reversible reactions where diglycerides and monoglycerides are formed

as intermediates as shown in figure 4.186.

Figure 4.1 Transesterification of triglycerides - Three-step consecutive reactions

Several factors affect the transesterification reaction. These include the molar ratios of

products, type of catalyst, free fatty acid (FFA) content of the lipid raw material, time

of reaction and temperature at which reaction occurs. The molar ratio of triglyceride

and alcohol is 1:3, however excess alcohol is used to increase the yield of fatty acid

alkyl ester and allow its phase separation from the glycerol formed.

TG + DG + R1COOCH3

DG MG R2COOCH3

MG GL R3COOCH3

+ +

+ +Overall reaction

TG GL 3RCOOCH3

CH3OH

CH3OH

CH3OH

+ 3CH3OH +

Where: TG : triglyceride

DG : Diglyceride

MG : Monoglyceride


53

The recovery of by-product glycerol and the excess alcohol from the final crude

mixture is incorporated as an essential step in commercial production of biodiesel fuel.

Returns from the by-product and recycling raw materials reduce the final cost of

production of biodiesel. Extracted and purified glycerol is used in food,

pharmaceutical and cosmetic industries.

Phase separation and purification of the product is also significantly important to the

final yield of biodiesel produced.

Acid Catalyzed Reaction

This is more suited for transesterification of lipid raw materials with high free fatty

acids as it also esterifies the fatty acid in the fats or oil. Acid-catalyzed reaction

enables production of long- and branched-chain esters that are difficult using alkaline

catalysts. However, when acid catalyst is used in high reaction temperatures it

promotes formation of unwanted secondary products such as dialkyl ether and

glycerol ethers.

Presence of any water in the (raw material or resulting from the reaction) is

detrimental to acid-catalyzed transesterification reaction. Esterification of FFA

produces water and this inhibits further reaction resulting in low conversion into alkyl

esters. Figure 4.2 illustrates the mechanism of acid transesterification reaction.


54

Figure 4.2 Mechanism of Acid Catalysed Transesterification of Lipids.

Acid transesterification of lipids starts with (1) protonation of the carbonyl group by the

acid catalyst; (2) nucleophilic attack of the alcohol, forming a tetrahedral intermediate

after which the (3) proton migration and breakdown of the intermediate step continues.

The sequence (1-3) is repeated twice in case of a triglyceride as shown.

Base Catalyzed Reaction

Alkaline catalysts have a lot of advantages over other catalysts. It is more economical

and effective than acid catalysts as reaction proceeds faster and to completion more

quickly with higher yields in absence of water. This type of catalyst is less corrosive

and safer to handle which is why they are most favourably used for biodiesel

synthesis. See figure 4.3 for mechanism of base catalyzed transesterification.

CH CH2

H2C

OR"COO

OOCR'

C

O

R'" CH CH2

H2C

OR"COO

OOCR'

C

OH+

R'"H

+ (1)

CH CH2

H2C

OR"COO

OOCR'

C

OH+

R'" + R4OH

CH CH2

H2C

OR"COO

OOCR'

R'"O

+

H

R4

OH

(2)

CH CH2

H2C

OR"COO

OOCR'

R'"O

+

H

R4

OH

CH CH2

H2C

OHR"COO

OOCR'

+ O

R'''

OR4

+ H+ (3)


55

Figure 4.3 Mechanism of Base Catalysed Transesterification of Lipids87

(1) Reaction of base with the alcohol, producing the alkoxide and the protonated

catalyst. (2) The nucleophilic alkoxide ion attacks at the carbonyl group of the

triglyceride generating a tetrahedral intermediate, which, in step (3), fragments to

release the alkyl ester (ROOCR”) and the corresponding anion of the diglyceride. In

step (4), the diglyceride anion is protonated regenerating the catalyst (B) for another

catalytic cycle. Diglycerides and monoglycerides are likewise converted by the same

mechanism to a mixture of alkyl esters and glycerol.

Other Production Processes

The use of raw material with different properties has already been explored in the

transesterification process. Examples include using homogenous, heterogenous and

enzymatic catalysts and supercritical methanol (chapter 3).

ROH + B RO- + BH

+

CH CH2

H2C

OR"COO

OOCR'

C

O

R'"+

CH CH2

H2C

OR"COO

OOCR'

C

O-

OR

R'"

CH CH2

H2C

OR"COO

OOCR'

C

O-

OR

R'"CH CH2

H2C O-

R"COO

OOCR'

+ ROOCR"'

CH CH2

H2C O-

R"COO

OOCR'

+ BH+

CH CH2

H2C OH

R"COO

OOCR'

+ B

(1)

(2)

(3)

(4)

-OR


56

For good ester conversion via alkaline transesterification reaction, the low-grade

(containing high Free Fatty Acid or FFA content) lipid raw materials are pretreated

(hydrolysed) to reduce the content of free fatty acids. A simple two-step acid

catalyzed pretreatment process, reduced the acid values of lipid feed stock, namely,

yellow grease (acid value of 18.03mg KOH/g) and brown grease (acid value of

79.20mg KOH/g) to less than 2mg KOH/g35 (1) FFA reacts with alkali catalysts

forming undesirable by-products (soap and water). (2) Water deactivates the catalyst

that aids in soap formation. Thus the cycle continues eventually inhibiting (slowing

down) ester formation. Figure 4.4 describes this.

R

O

OH

+ NaOH ( or MeONa)

R

O

O-Na

+

+ H2O ( or MeOH)

Soap

R

O

OMe

+ H2O Base Catalyst

R

O

OH

+ MeOH

(1)

(2)

Figure 4.4 Soap formation due to high FFA and deactivation of catalyst during Base

catalysed transesterification process

Product Purification

After phase separation of the reaction mixture the product needs to be purified to

achieve maximum ester yield and optimum quality biodiesel. Excess methanol can be

removed by heating the ester layer, however this is not economical for commercial

production thus a much easier and safer alternative is to wash it with water. Saline

water can be used for easy separation. Washing also removes traces of glycerol. Most

glycerol gets separated out in the separation phase, however it can also be removed by


57

converting it into FFA by adding alkaline catalyst. Acidified water is recommended

for this, which also clears out catalyst and alcohol residues. Acid washing requires

special equipment to facilitate safe purification process and adds on to the production

cost. Another way of purifying ester from FFA is by distillation (esters have lower

boiling point then its FFA).

This chapter investigates the synthetic methods and purification process of methyl and

ethyl esters (biodiesel). The locally available raw materials identified in pervious

chapter are used. The effect of parameters affecting tranesterification like high FFA

and water content of lipid raw material are reduce or eliminate by introducing

pretreatment processes. Optimization of pretreatment and transesterification process

are carried out to produce quality biodiesel. The effect of catalyst and alcohol is also

investigated together with different purification methodologies of crude biodiesel.

The quality of biodiesel is later determined using gas chromatography (GC) and gel

permeation chromatography (GPC) (Chapter 5).


58

4.2 METHODOLOGY

4.2.1 Synthesis Process

The methods investigated for making biodiesel from various oils and alcohol are

categorized in the Venn diagram illustrated in figure 4.5.

Figure 4.5 Successful ester (biodiesel) synthetic methodologies.

A is the set of successful methodologies (acid or base catalyzed and one step or two step) used

for the synthesis of biodiesel (methyl or ethyl esters) from different lipid sources as described

in the text.

Method 1 – Acid pretreatment, one step base catalyzed transesterification,

Method 2A – One step base transesterification,

Method 2B – Two step base transesterifcation and

Method 3 – Base neutralization, one step base transesterification.

In chapter 3, it was found that some of the lipid raw materials contained too much

FFA (i.e., > 1.0%) or moisture content (>1.00% by weight of sample) for efficient

Coconut Oil Methyl Ester

Waste Oil

Methyl Ester

Coconut Oil Ethyl Ester

Waste Oil Ethyl

Ester

Soybean Oil Methyl Ester

Canola Oil Methyl Ester

Coconut Oil Methyl Ester

Coconut Oil Ethyl Ester

1

3

2A

2B A


59

base-catalysed transesterification. The following actions were taken to make the raw

materials more suitable:

Table 4.1 Treatment of lipid raw materials undertaken prior to

transesterification reactions to produce biodiesel

Existing Unsuitable variables Solution/ treatment

High FFA% content of lipids • Acid pretreatment (method 1) process where the FFA is esterified.

• Base neutralisation (method 3), where excess base catalyst destroys FFA and transesterification of triglycerides is completed with catalyst amount of 1% by weight of oil.

High moisture content • Oil samples were heated over hotplates at 70ºC for 5-6 hours with constant stirring. This method was developed to ensure that the FFA% content remained same after dehydration process.

The flowchart illustrated below describes the fate of lipid raw material in the biodiesel

synthetic process. Determination of free fatty acid (FFA) content of oil (Chapter 3) is

an essential quality control measure that needs to be known prior to transesterification

reaction.

Figure 4.6 Fate of Lipid Feedstock Depending of their Free Fatty Acid Content.

Lipid Feedstock

Pretreatment: 1) Acid Catalyzed 2) Base Neutralised

Transesterification Using Base catalyst in

alcohol (methanol/ethanol)

FFA >1%

FFA>1%


60

4.2.1.1 Method 1 Acid pretreatment, one-step base-catalysed transesterification

This method is used for lipid raw materials with high FFA content (>1.00% FFA or

acid value >2.00 mg KOH/g)88. These include only coconut and waste oils in this

research. All samples were pre-dried using the method in Table 4.1.

Figure 4.7 Flowchart Illustrating Procedure for Method 1

PR

ETR

EA

TM

EN

T

BA

SE

TR

AN

SE

STE

RFIC

ATIO

N

PU

RIF

ICA

TIO

N

Sulphuric acid +

Alcohol +

Oil with FFA% >1%

Pretreated Oil

Alcohol Layer

1

2

3

45 6

7

8

9

1 10

2

3

45 6

7

8

9

11

Oil + Acid + Alcohol

1

2

3

45 6

7

8

9

1 10

2

3

45 6

7

8

9

11

Stirrer

Base

catalyst +

Alcohol Pretreated oil + Base catalyst +

Alcohol

BIODIESEL

Wash water

Wash water (distilled or saline

water)


61

PROCEDURE

Acid Pretreatment

To 200 ± 1g of coconut oil (FFA as lauric acid 3.52% as per analysis method of

chapter 3) in a round bottom flask was heated to 60 ºC and to this was added a

warmed (60 ºC) solution of concentrated sulfuric acid (0.4ml, representing 0.1g

H2SO4 per 1.0g FFA) in methanol (28.5ml representing 20 mole methanol per mole of

FFA, formally lauric acid Mr = 200g/mol)and the resulting mixture heated to reflux

with magnetic stirring for 1.5 hours before being transferred to a separating funnel,

cooled and separated. The triglyceride (lower) layer was washed three times with

10ml portions of methanol to remove the acid catalyst and water of reaction. The

exact quantities of ingredients used are given in the Appendix Table A15.

The FFA content of the pretreated oil (see Appendix Table A.16) was determined

using A.O.C.S official tentative method Ca 5a-40. If the FFA content was <1.00 % or

2.00 mg KOH/g then it was transesterified using one step base transesterification

process as described below. However, if this was not the case, further pretreatment

process was carried out in a similar manner as described, but this time with a 40:1

molar ratio of triglycerides to methanol. This followed a washing process with

absolute methanol and the FFA content was measured. Washed pretreated lipid layer

was then transesterified according to one step base transesterification process.

The FFA content of all oil samples pretreated in this experiment reduces to < 1% after

treatments.


62

Note that the method explained is based on coconut oil as lipid raw material; waste oil

was also used to prepare methyl esters using this method.

CALCULATION

Amount of catalyst- sulphuric acid (ml)

Where:

1.8 g/moles is the density of absolute methanol

M (H2SO4) is the mass of sulphuric acid and is calculated using the following

equation;

Where:

M (FFA) is the mass of FFA in oil raw material weighed out and is calculated

using the following equation;

Where:

M (oil) is the mass of oil sample (g)

FFA% is the amount of FFA% of the oil sample obtained by A.O.C.S official

tentative method Ca 5a-40.

Volume of sulphuric acid = molesg

M SOH

/8.1)( 42

)()(10010

42 FFASOH MM ×=

)()(100

%oilFFA M

FFAM ×=


63

Volume of methanol

Where:


M (MeoH) is the mass of absolute methanol and is calculated using the

following equation;

* used 40 when calculating methanol volume for the second pretreatment process.

Where:

M (FFA) is the mass of FFA in oil raw material weighed out

Mr ( FFA) is the molecular weight of free fatty acid being analysed. Lauric

Acid in this case

Mr ( MeOH) is the molecular weight of methanol

Constant 20 is the molar ratio of triglyceride/methanol in the first

pretreatment process.

Base Transesterification of Pretreated Oil (One Step)

PROCEDURE

Sodium methoxide, the base catalyst for transesterification was prepared by

dissolving sodium hydroxide (analytical grade) in absolute methanol. The amount of

sodium hydroxide (1.09g) was calculated base on the amount required to neutralize

Volume of methanol =molesg

M MeOH

/791.0)(

)()(

)()( *20 MeOH

FFA

FFAMeOH Mr

Mr

MM ××=


64

the FFA content of the pretreated lipid (FFA%, 0.49% or acid value, 1.38 mg KOH/g)

plus 1% of the unreacted oil mass. The volume of absolute methanol (38.2 ml) was

calculated based on the molar ratio of oil/absolute methanol which was 1:6. Sodium

hydroxide was then swirled at room temperature to dissolve in alcohol to make an

alkoxide catalyst (see Appendix Table A.17)

In a typical reaction, 100.5g of the oil was heated to 60 °C in a round-bottom flask

that was loosely stoppered to avoid introduction of moisture, which can destroy

catalyst and result in undesirable by-products such as soap. A preheated (60 °C)

solution of catalyst in methanol (prepared as above) was rapidly added to this through

a funnel and the resulting mixture was magnetically stirred and heated to boiling

under a reflux condenser. After two hours of boiling with magnetic stirring, the

reaction mixture was transfered to a separating funnel and allowed to cool to room

temperature. The lower glycerolic layer was removed and the upper ester layer (crude

biodiesel) was purified as described below (see 4.2.2 Purification).

Where ethanol was used instead of methanol the preheating temperature was

increased to 75 °C (just below the alcohol's boiling point).

CALCULATION

Amount of Catalyst

Where,

M (p. oil) is the mass of pretreated oil

Mass of catalyst to neutralize acid 4056

1

1000

)( ×××= ValueAcidM oilpretreated


65

Acid Value (mg KOH/g) is obtained by AOCS official tentative method Ca 5a-40.

Constant 40 is the molecular weight of sodium hydroxide

Constant 56 is the molecular weight of potassium hydroxide

Amount of methanol

Where:



following equation;

Where,

M (p. oil) is the mass of pretreated oil

Constant 6 is the molar ratio of excess amount of methanol

Constant 32 is the molecular weight of methanol

Mr( triglyceride) is the molecular weight of the triglyceride. Use the following molecular

weight of triglyceride when using the respective pretreated oil:

Volume of methanol =molesg

M MeOH

/791.0)(

326)()(

)( ××=detriglyceri

oilpretreated

Mr

MMeOHM


66

Table 4.2 Molecular weights of Triglycerides in Lipid Raw Material.

Triglyceride Molecular weight (g/moles) Oil*

Trilauryl glycerol 639.00 Coconut oil

Trioleoyl glycerol 885.43 Soybean oil

Canola oil

Tripalmitoyl glycerol 806.74 Waste oil- source 1

Trioleoyl glycerol 885.43 Waste oil- source 2

- source 3

* Same molecular weights are used for calculation in preteated oil.

4.2.1.2 Method 2A - One Step Base Transesterification (No pretreatment)

This method is employed to produce methyl and ethyl esters from lipid source with

FFA content <1.00% or acid value <2.00 mgKOH/g. The oils used in this method

included canola oil, soybean oil, two samples of waste oil (FFA% was <1.00%), and

coconut oil which was used as comparison purposes.

This method was used to explore the variables affecting transesterification to produce

esters and their purification. These variables include:

Type of catalyst: sodium hydroxide versus potassium hydroxide

Types of alcohol: methanol versus ethanol


67

Figure 4.8 Flowchart Illustrating Procedure for Synthetic Method 2A

PROCEDURE

The catalyst was prepared by dissolving the alkali (NaOH or KOH) in the alcohol

(methanol or ethanol) at room temperature taking care to avoid the introduction of

moisture.

BA

SE

TR

AN

SE

ST

ER

FIC

AT

ION

P

UR

IFIC

AT

ION

1

2

3

45 6

7

8

9

1 10

2

3

45 6

7

8

9

11

Base

catalyst +

Alcohol Lipid (oil) +

Base catalyst + Alcohol

BIODIESEL

Wash water


water)


68

In a typical reaction, 200.0g of soybean oil was heated in a loosely stoppered round-

bottomed flask to 60 °C in a water-bath and to this was added (rapidly through a

funnel) a preheated (60 °C) solution of KOH (2.00g or 1.0% of the oil mass) in

methanol (55.11 mL, for a 6:1 methanol/triglyceride ratio). The resulting

heterogeneous mixture was magnetically stirred and heated to boiling under a reflux

condenser for 1.5 hours. The mixture was transferred to a separating funnel and

allowed to cool. The lower glycerolic layer was removed and the upper ester layer

(crude biodiesel) was purified as described below (see 4.2.2 Purification).

CALCULATION

Amount of Catalyst

Where,

M (oil) is the mass of oil

Amount of methanol

Where:



following equation;

Where,

Mass of catalyst = 1001

)( ×oilM

Volume of methanol = molesg

M MeOH

/791.0

)(

M (MeOH) = 326)(

)()( ××=

detriglyceri

OilMeOH Mr

MM


69

M (oil) is the mass of oil

Constant 6 is the molar ratio of excess amount of methanol

Constant 32 is the molecular weight of methanol

Mr( triglyceride) is the molecular weight of the triglyceride. Use the following molecular

weight of triglyceride when using the respective pretreated oil:


70

4.2.1.3 Method 2B – Two-Step Base Transesterification (No pretreatment)

Figure 4.9 Flowchart Illustrating Synthetic Procedure for Method 2B

PROCEDURE

The two-step procedure 2B in the same as procedure 2A except that only 75% of the

catalyst mixture is added in the first step. The mixture was heated to reflux for 1.5

hours, transferred to a separating funnel, allowed to cool and the glycerolic layer

removed. The upper layer was transferred back to the round-bottom flask and the

remaining 25% of catalyst mixture was then added and the resulting mixture heated

under reflux with magnetic stirring for a further 1.0 hours. The reaction mixture was

finally transferred to a separating funnel, allowed to cool and the upper ester layer

(crude biodiesel) purified as described below (see 4.2.2 Purification).

BA

SE

TR

AN

SE

ST

ER

FIC

AT

ION

P

UR

IFIC

AT

ION

1

2

3

45 6

7

8

9

1 10

2

3

45 6

7

8

9

11

Base

catalyst +

Alcohol

Lipid (oil) + Base catalyst +

Alcohol

BIODIESEL

Wash water


water)

¾ of the mixture is added at the beginning of reaction and ¼ after an hour.


71

Note: In some cases, no separation occurred, and the remaining catalyst mixture was

still added to complete transesterification process.

4.2.1.4 Method 3 Base Neutralisation, One Step Base Transesterification

This method was used for preparing ethyl esters from oil containing high FFA

(>1.00% or acid value of 2.00mgKOH/g). Coconut oil and waste oil both have high

FFA and used as lipid sources for this method.

Figure 4.10 Flowchart Illustrating Synthetic Procedure for Method 3

BA

SE

TR

AN

SE

ST

ER

FIC

AT

ION

P

UR

IFIC

AT

ION

1

2

3

45 6

7

8

9

1 10

2

3

45 6

7

8

9

11

Lipid (oil) + Base catalyst +

Alcohol

BIODIESEL

Wash water


water)

Base catalyst (MOLAR EXCESS)

+ Alcohol


72

PROCEDURE

Potassium hydroxide (1.36g) was used as catalyst for ethanolysis reaction. The

amount was calculated based on the FFA amount in the feedstock i.e. the amount of

catalyst required to neutralize the FFA in oil plus 1% of the oil sample. A 6: 1 molar

ratio of ethanol: triglyceride was used. See Appendix, tables A.26 and A.27. The

catalyst mixture preparation and transesterfication process was same as the steps

described in method 2A. The preheating and reaction temperature was 75ºC if ethanol

was used.

4.2.2 Purification

Purification process involved washing of ester layer collected after transesterification

to remove water-soluble contaminants like unreacted catalyst and alcohol. The use of

saline water was explored as an effective washing agent relative to distilled water at

room temperature. Saline water is readily available in the Pacific region and could be

utilized for washing process reducing the cost factor of production.

PROCEDURE

Comparison between using distilled water and saline water washing was made. The

washing technique was also tried which included spraying water with:

1. garden spray (fine nozzle);

2. wash bottle (direct and strong dispersion); and

3. adding an equal volume of water and shaking in a separating funnel (agitation)


73

The best washing technique was determined based on the time required for the ester

layer and wash water layer to separate. The visual clarity of the wash water layer was

also compared with other wash water layer from esters prepared using the same

method. The best washing technique was then employed to purify all subsequent

biodiesel samples.

Distilled water washing

25-50ml of crude ester layer was taken in a separating funnel and washed (sprayed)

with distilled water. After each washing process the mixture was allowed to separate

for 12 hours before any observations were made. The lower layer (water and water

solubles) was discarded and the upper layer (containing esters) was washed with the

next portion of water. Each sample was washed three times with equal amount of

water adding up to 3 times more water as the sample.

Saline water washing

Moderate saline water (3.5g of NaCl in 1liter of distilled water) was prepared to

depict the seawater. This was then sprayed on to 25-50 ml of crude ester sample in a

separating funnel and left to settle for 12 hours. The lower layer (water and water

solubles) was discarded and the upper layer (containing esters) was washed with the

next portion of water. The samples were washed with equal portions of saltwater

amounting to 3 times more than the sample volume. After the third washing similar

washing process was continued with distilled water to remove the salinity introduced

via salt water cleansing.


74

Infra red (IR) analysis

After washing process IR analysis of each sample was carried out to ensure that

alcohol and water was not present in the samples. This was done using Perkin Elmer

FT-IR spectrometer spectum 1000 instrument using winlab software.

Samples were prepared for analysis by placing a drop of sample between two cleaned

and dried sodium chloride discs. The percentage transmittance (T%) was obtained by

scanning between 400-4000 cm1− wavelengths.


75

4.3 RESULTS AND DISCUSSION

4.3.1 Method Optimization

Type of catalyst

Potassium hydroxide and sodium hydroxide were investigated as basic catalyst for

transesterifcation reaction to produce biodiesel.

Sodium hydroxide dissolved in ethanol

results in a semi solid solution after

some time. When this is heated and

added to preheated (75 ºC) coconut oil

it forms a jelly solution. This causes

difficulty in stirring the mixture during

Figure 4.11 Miscibility Problems during Synthesis of Biodiesel

transesterification process. Even if the mixture turns into liquid state due to heating

and stirring, it jells back after the mixture is cooled to room temperature which is not

ideal for fuel. The jelling effect of coconut oil is accentuated by high amounts of

FFA% content in the oil89. This was not observed when the catalytic mixture was

added to soybean or canola oil.

Potassium hydroxide was used alternatively to avoid the jellying problem during

ethanolysis reaction. It is compatible with both ethanol and methanol solvents.


76

The optimum percentage of each catalyst was determined by observing the amount of

soap (off white layer that floats on water layer, just below ester layer) produced and

the amount of water required to completely clean the crude biodiesel.

Table 4.3 Trial for suitable catalyst for transesterification reaction and its

observation

Trials Observations Methanolysis

1% NaOH with oils containing low FFA% (<1.00%)

- catalyst easily miscible with methanol during catalyst preparation - no soap produced - good separation of wash water and lipid layer.

1% NaOH with oils containing high FFA% (>1.00%)

- Observations were similar to reaction with low FFA% oil but soap was produced in this case and required several washing before it cleared out.

Ethanolysis 1% and 0.5% NaOH with oils containing low FFA%

- catalyst forms jell after some time with ethanol during catalyst preparation

- no soap produced - good separation of wash water and lipid layer.

1% NaOH with oils containing high FFA%


- soap produced that requires several (8-10 times with equal amount of water as the ester layer, each time) washing with water.

- No good separation of wash water and lipid layer as heaps of soap is produced.

0.5% NaOH with oils containing high FFA%


- less soap produced that requires bit less (5-7 times with equal amount of water as the ester layer, each time)washing with water to clear out.

- No good separation of wash water and lipid layer as heaps of - soap is produced.

1% KOH with oils containing high FFA%

- catalyst is miscible with ethanol during catalyst preparation - soap produced that requires several (8-10 times with equal amount of

water as the ester layer, each time) washing with water. - No good separation of wash water and lipid layer as heaps of soap is

produced. 0.5% NaOH with oils containing high FFA%

- catalyst is miscible with ethanol during catalyst preparation - less soap produced that requires bit less (5-7 times with equal amount

of water as the ester layer, each time)washing with water to clear out. - No good separation of wash water and lipid layer as heaps of soap is

produced.


77

Pretreatment trials (Method 1)

The purpose of pretreatment is to reduce the FFA % content of lipid raw material

containing high FFA% to meet the prerequisites for base transesterification i.e. FFA%

should be < 1.00%.

The molar ratio of alcohol/FFA and the catalyst content was explored in order to

determine the best system of pretreatment. The experimental trials carried out are

summarized in Table 4.4 below.

Table 4.4 Optimizing Pretreatment Coconut Oil Using Acid Catalyst and

Methanol.

Molar excess of methanol to FFA 20:1

Catalyst amount 10% (a) Catalyst amount 5% (a)

1 2 3 1 2 3

FFA % before pretreatment

3.58 3.52 3.52 3.92 4.03 4.11

FFA% after pretreatment

0.52 0.53 0.78 1.14 1.55 1.63

Ratio of FFA% reduced(b)

6.07 6.64 4.5 3.44 2.60 2.52

(a) acid catalyst – sulfuric acid, amount calculated based on mass of coconut oil.

(b) calculated for comparison purposes: (FFA% before pretreatment/FFA% after pretreatment)

From the pretreatment trial it can be observed that the ration of FFA% reduced is

greater when a molar ratio of 20:1 (methanol/FFA) is used with 10% catalyst

(calculated based on mass of oil). This combination effectively reduces the FFA% to

the required level as suggested by Canakci. M et al, 200188. However, Canakci’s

study was carried out using lipid raw material with higher FFA% as compared to this

research, thus the 5% catalytic content was considered to be investigated. Kinetic


78

studies on esterification of FFA with methanol in presence of sulphuric acid proves

that much higher molar ratios alcohol can be used achieve similar results in less time90.

This method could not be used to produce ethyl esters as the ethanol and lipid layers

could not be separated after acid pretreatment. This is due to the fact that the oil is

more soluble in ethanol than in methanol. Several trials were carried out using ethanol

as alcohol source for pretreatment process but it was observed that the FFA%

decreased very slightly with 20: 1 (ethanol/FFA) molar ratio with both the10% and

5% catalyst content. However, increasing the molar ratio to 40:1 (ethanol/FFA in oil)

it was seen that the hydrolysis of FFA was greater (Table 4.5). Also having a greater

molar ratio induces good separation of the alcohol/water/acid layer from the lipid

layer.

Table 4.5 Optimizing Pretreatment Process of Coconut Oil using Acid Catalyst

and Ethanol.

Excess molar ratio of ethanol/FFA in coconut oil

40:1 20:1

Catalyst amount (a) Catalyst amount (a)

10% 5% 10% 5%

FFA % before pretrteatment

3.92 4.04 3.66 3.92

FFA% after pretreament

1.31 2.36 2.22 2.22

Ratio of FFA% reduced(b)

2.98 1.71 1.64 1.77

(a) acid catalyst – sulfuric acid, amount calculated based on mass of coconut oil.

(b) calculated for comparison purposes: (FFA% before pretreatment/FFA% after pretreatment)

It was also noted that the separation of coconut oil and methanol layer was less

obvious than waste oil and methanol layer during the pretreatment process. The

chemical composition of each oil influences its miscibility with the solvents used.

Coconut oil has a greater composition of average length lipids (C8-C20), whereas


79

used oil contains major constituents that are longer chains of fatty acids (> C20) some

of which gets introduced

from the food stuff cooked in it.

Thus from the trial carried out, 20:1 (methanol/FFA) and 10% catalyst is optimum for

pretreatment of an oil under going methanolysis. Using ethanol in a molar excess >

40:1 (ethanol/FFA) for pretreatment of oil undergoing ethanolysis process to produce

ethyl esters (biodiesel).

4.3.2 Observations and results for the methodology used to prepare biodiesel

Acid pretreatment, one-step base transesterification (1)

Methanolysis

The methanol/water/acid layer was evidently separated from the lipid layer after

pretreatment process. After the methanolysis of pretreated oil the glycerol layer and

ester layer were also obviously separated without any intermediate layers (A). The

washing process of ester layer was efficient, as the wash water became clear (B) in a

few washings (3-4 times). However it should be noted that using higher molar ratios

of alcohol limits phase separation of the glycerol and biodiesel layer after

tranesterification.


80

Figure 4.12 Treatment of Reaction Mixture to Obtain Purified Biodiesel

A – Showing very distinct separation of the glycerol and crude biodiesel layers. The later is then

purified through washing process. B shows the purified biodiesel sample with excellent clarity after

washing.

Ethanolysis

No ethanolysis was carried out as the ethanol and lipid layer does not separate after

pretreatment process. Attempts were made to remove the ethanol layer using

rotavapour technique or heating but in each case only the ethanol get removed leaving

the water and acid (from acid catalyst, sulphuric acid) content in the solution. This

was known from the FFA% content of the pretreated oil as the FFA% content

increased after treatment and removal of ethanol as compared to the FFA% of the oil.

For commercial production these methods would not be practical as it would add onto

the cost of production and demand more energy input as heating in involved.

One step base transesterification (2A) and two steps base transesterification (2B)

Methanolysis

For all types of oil, methanolysis showed results as predicted. There was homogenous

mixing of catalyst solution (sodium hydroxide and methanol) with oil when added. At

the end of the reaction the glycerol layer and ester layer separated distinctly with no

Crude Biodiesel

Crude Glycerol

A

Biodiesel

Wash Water

B


81

intermediate layers thus only the ester layer was introduced to the purification stage.

Soap was produced when washing methyl esters of lipids with high FFA content such

as coconut oil.

Methyl esters from soybean oil and canola oil were

easy to purify as the wash water became clear after

3-4 washings. Once water was sprayed onto the

ester layer the separation of ester and water layer

was separated quickly (10 minutes). With coconut

oil this was not the case (figure 4.13). Several

washings were required (5-8 times) before the

wash water became clear.

Figure 4.13 Soap formation while washing crude biodiesel (methanolysis)

The time for ester layer and water layer to separate after the first few washing took at

most 12 hours. But the layers required less time to separate well in the later washings.

Ethanolysis

It was observed that the glycerol and the ethyl ester did not separate at all for any of

the lipid raw materials explored so far. This is due to the excess ethanol present in the

crude ethyl ester mixture. Thus where 50ml of the crude biodiesel and glycerol layer

was washed with water the glycerol and ester layers separate after a few washings.

This is due to the removal of excess ethanol with wash water in the solution. The

amount of washing and the time required for the wash water and ester layers to

separate were similar to those for methanolysis after that. More washing was required


82

for coconut oil than for soybean or canola oil and the time required for the water and

ester layers to separate was slower for coconut oil ethyl esters in its first few washings.

Washings were more easily separable.

Base Neutralisation One-Step Base Transesterification (3)

This method is specifically targeted for the ethanolysis of lipid raw material with high

FFA% content. During and after the reaction process the separation of glycerol and

ester layer is not evident. (Thus, 50ml of the crude biodiesel and glycerol layer is

washed).

The excess base that is used to neutralize the FFA of

lipids also creates problems during the washing process

because it forms soap. For the chemical equation see 4.1.

Introduction. This eventually gets washed out and the

pale biodiesel layer becomes more evident.

Figure 4.14 Excess Soap Formation while Washing Crude Biodiesel (ethanolysis)

Thus, in the purification process of this method there is a lot of soap formation,

though the ester layer can still be purified. This method is not recommended for use

with lipid raw material with very high FFA% as excessive amount of soap will be

formed and the esters formed will be lost during purification process.


83

4.3.3 Observations and results for purification process

4.3.3.1 Washing Method optimization

The following methods of water washing were investigated to purify the ester

produced.

Garden spray (fine nozzle)

This was found to be the best way of washing the ester with water. It was observed

that very fine droplets of water dispensed from the nozzle settle in the bottom layer

having passing through the organic layer collecting water-solubles over a larger area.

The wash water became clear after only a few washings and the time required to settle

and separate the water from the ester layer was moderate (4-6hours).

Wash bottle (direct and strong dispersion)

The wash water obtained after using wash bottle for washing was still milky even

after 5-8 washes. This was due to the water being sprouted on only one spot of the

ester layer and washing only that portion. It was observed that the whole layer does

not get washed during washing, as water being dispensed from the wash bottle does

not cover the whole ester layer surface. But the time required for the separation of

ester and water layer was very quick (15-30 min) and no emulsion was formed

between the organic and aqueous layers.

Adding equal amount of water and shaking the separating funnel (agitation)

This was found to be the most unfavourable method as shaking the transesterified

mixture causes an emulsion, which took several hours to separate (sometimes more


84

than 12 hours). On the plus side, the wash water was usually clear after a few

washings. In some occasions, however, an intermediate layer was formed which was

difficult to get rid of, even with extended hours of settling.

The percentage of water-soluble products lost during washing process aids in

mapping out the best method for biodiesel synthesis. These products include excess

alcohol, soluble glycerides and soap. It has been observed that loss of ester occurs

when there is great formation of soap as it gets trapped in between and washed away.

Thus it is important to note the percentage of purified biodiesel retrieved after the

washing crude biodiesel. As the molar ratio of the reactants are similar for all methods

investigated comparison can be done. The following formula was used :

Table 4.6 Percentage Loss of water soluble during purification of biodiesel

synthesized using the methods investigated.

Samples Method of

Synthesis

Range (%) Median (%)

Coconut Oil Methyl Esters 1 12.10-20.56 16.44

2A 15.72-24.07 19.32

2B 15.40-27.76 19.57

Coconut Oil Ethyl Esters 2A 38.108-55.05 44.21

2B 33.90-66.21 43.05

3 55.15-74.83 61.66

Waste Oil Methyl Esters 1 16.22-25.33 18.61

Waste Oil Ethyl Esters 3 75.64-89.91 85.71

Comparing the results (medians) relative to the method of synthesis used it can be

seen that there is less % loss of water solubles in methanolysis than ethanolysis.

% Loss of water-soluble = (Mass of crude Biodiesel - Mass of washed Biodiesel) x 100 Mass of crude Biodiesel


85

Method 3 is not an efficient method as more than 50% of the crude product is lost

before biodiesel purifies, with 61.66% and 85.71% lost in washing. Note that the

decision that the product is purified is based on the clarity of the washed biodiesel.

Methods 2A and 2B are more effective for methanolysis (19.32% and 19.57%

respectively) of coconut oil than ethanolysis (44.21% and 43.05%). Out of all the

methods investigated for methanolysis of vegatable oil, method 1 was the best with %

loss of water solubles as 18.61% and 16.44% for waste oil and coconut oil,

respectively.

4.3.3.2 Comparison of washing processes using distilled water and saline water

Saline water

Use of saline water during washing is appropriate when there is soap formation in the

mixture after transesterification. It has a salting out effect that makes it easier for the

soap to fall out of solution and form a distinct layer between the ester and water layers.

This way removal of soap from the solution becomes more efficient than using

distilled water. One of the drawbacks of this wash water is that the salinity

accumulated during saline water wash needs to be completely removed or else it will

corrode the engine parts when used as fuel. Thus, for this reason the ester layer was

given a final wash with distilled water in a similar amount as saline water.

Distilled water on the other hand is best for transesterified products that have low or

no soap formation. These can be produced from lipid source with low FFA% or

pretreated oils, which have high FFA%. Using distilled water saves washing time and

resources required to about half, as extra washing is not needed.


86

Table 4.7 Purification of Coconut Oil Ethyl Esters with Distilled and Saline

Wash Water

Sample A - mass of crude ester before washing

Mass of empty bottle

Mass of bottle with washed ester

B - mass of washed ester

% loss of water solubles due to washing (A-B)/A x 100

C001coco-2A-WBDE 25 25.5454 40.1992 14.6538 41.38 C001coco-2A-WBDE-salt 25 25.5491 40.4395 14.8904 40.44 C001coco-2B-WBDE 25 25.628 39.7261 14.0981 43.61 C001coco-2B-WBDE-salt 25 25.8449 40.0898 14.2449 43.02 C001coco-3-WBDE 25 16.1625 24.8592 8.6967 65.21 C001coco-3-WBDE-salt 25 15.9422 24.8822 8.94 64.24






Note: samples washed with saline water are denoted with prefix – salt.


87

As can be seen for table 4.7 the percentage of water solubles lost during the process of

washing is slightly less or equivalent to samples washed in both samples that are

washed with distilled water and saline water. It should be noted that major loss of

ester does not occur due to extra washing required to remove salinity when washed

with saline water.

4.3.4 Infrared analysis

After washing the Infrared analysis of each sample was carried out. The spectra

Figure 4.15 Infrared Spectra of Ester Before Purification Process

Figure 4.16 Infrared Spectra of Ester After Purification Process

4000.0 3600 3200 2800 2400 2000 1800 1600 1400 1200 1000 800 600 400.0

0.0

5

10

15

20

25

30

35

40

45

50

55

60

65

70

75

80

84.9

cm-1

%T

3457,78

3005,32

2926,0

2853,4

1740,1

1652,76

1644,78

1463,28

1373,36

1345,54

1302,48

1243,33

1181,16

1113,49

1097,45

1034,41

970,78

916,74 859,74

724,49

2734,792677,79


88

The characteristic absorption peak of alcohol is usually a strong broad band between

3400-3650 cm-1. Peak at 3525 cm-1 and 3457 cm-1 in figure 4.16 explains the presence

of methanol/ethanol/water in the sample. This peak confirms that there is extremely

low amount of alcohol or water present.

Chapter 5 Chemical and Physical Analysis of Biodiesel

89

5 CHAPTER 5 CHEMICAL AND PHYSICAL ANALYSIS

OF BIODIESEL

5.1 INTRODUCTION

The use of biodiesel as an alternative to automotive diesel fuel and its efficiency as

fuel depends solely on its quality. Biodiesel standards have been established to

maintain the consistency in the fuel quality by characterizing biodiesel fuel, see

chapter 2. The fatty acid composition of the lipid raw material is the major factor

influencing the fuel properties of biodiesel fuel. These include its physical and

chemical properties. As a consequence the quality control of the oleo chemical

products is essential in biodiesel production. Some common fatty acids and their ester

are listed in table 5.1 below. Accordingly the analytical methods employed to

determine these are of great significance.

Table 5.1 Some Common Fatty Acids and There Esters

Fatty Acid Structure of Its Esters* Common Acronym

(Methyl)/(Ethyl) Ester

Lauric acid/ Dodecanoic acid

R-(CH2)10-CH3 C12:0 M/E Laurate or M/E Dodecanoate

Palmitic acid/ Hexadecanoic acid

R-(CH2)14-CH3 C16:0 M/E Palmitate M/E Hexadecanoate

Stearic acid/ Octadecanoic acid

R-(CH2)16-CH3 C18:0 M/E Stearate M/E Octadecanoate

Oleic acid/ 9(Z)- Octadecanoic acid

R-(CH2)7-CH= CH-(CH2)7-CH3

C18:1 M/E Oleate M/E 9(Z)- octadecanoate

Linoleic acid/ 9(Z),12(Z)-

octadecadienoic acid

R-(CH2)7-CH= CH-CH2-CH=CH-(CH2)4-CH3

C18:2 M/E Linoleate M/E 9(Z),12(Z)-

octadecadienoate Linolenic acid/

9(Z),12(Z),15(Z)- octadecatrienoic

R-(CH2)7-(CH= CH-CH2)3-CH3

C18:3 M/E Linolenate M/E 9(Z),12(Z),

15(Z) octadecatrienoate * Methyl ester R = -CO2-CH3 and Ethyl Esters R = -CO2-C2H5


90

Factors Affecting Fuel Quality

The chemical contaminants escaping through the purification processes are a major

cause of degradation in the quality of biodiesel fuel. Contaminant can be by-products,

reactants or incomplete transesterified products. Unreacted triglyceride and other

acylglycerols intermediates (monoglyceride and diglycerides) are formed during the

course of transesterification reaction. For example, intermediates formed when

trilauric acid undergoes transesterification shown in figure 5.1. The triglycerides,

diglycerides and monoglycerides are partially composed of bound glycerol. This is

added to free glycerol to get total glycerol. Together with these contaminants, residual

alcohol and wash water content have an existing limit for its permissible levels in

biodiesel fuel.

Figure 5.1 Intermediates formed from transesterification of trilauric acid

Physical parameters also contribute to the quality of biodiesel fuel. The physical

factors are also majorly due to the type and source of the lipid raw material and the

synthetic process. Some of these fuel properties are also applicable to conventional

diesel fuel. The lipid raw material of biodiesel fuel is basically reflected by the nature

and composition of fatty acids present in it. This has an effect on the oxidation and

stability of the final biodiesel product. Some physical factors include viscosity, cold

temperature properties, cetane number, heating value, flash point and density.

CH2OH

CH2OH

CH2OOR1

Monoglyceride

CH2OH

CH2OOR1

CH2OOR1 Diglyceride

Where R1 = (CH2)10-CH3


91

Table 5.2 Property Data for Methyl Ester Biodiesel Fuels 91

Source oil Density

g/[email protected] C

Viscosity

cSt@40 C

Cetane

Heating Value

MJ/kg

Cloud point C

Palm 0.880 5.7 62 37.8 +13

Soybean 0.884 4.08 46.2 39.8 +2

Sunflower 0.880 4.6 49 38.1 +1

Tallow 0.887 4.1 58 39.9 +12

Biodiesel Analytical Methods

Several chromatographic, spectrometric and wet chemistry (mostly to determine

physical properties) analytical methods have been carried out to determine the quality

of fuel. Gas chromatography (GC) technique has been identified as the most common

instrumentation method for biodiesel characterization. High Pressure Liquid

Chromatography (HPLC) 92 technique is the next popular. Other methods include

Thin Layer Chromatography (TLC), Nuclear Magnetic Resonance (NMR)

spectroscopy93, Ultraviolet (UV) spectroscopy94 and Near Infrared (NIR)

spectroscopy95.

The ester contents and in biodiesel using gas chromatographic techniques have been

carried out using Flame Ionization Detectors (FID). Its quantification has been done

using the method of internal standards, external standards or calibration method.

Methyl heptadecanoate is considered to be a common internal standard mainly as

heptadecanoic acid is an uncommon naturally occurring fatty acid in some vegetable

oils. However, its natural presence has been found in animal fat and oil which resulted

in showing increased ester content (2-7%w/w) as compared to results obtained using

EN 14103 uniform European quality standard method for fatty acid methyl ester

(FAME). Other detectors used includes Mass Spectorscopy (MS) detector that is


92

coupled with GC for fragment identification. Use of appropriate temperature-

programming methods in GC technique enable separating and quantification of short

chain fatty acid esters (C8-C12) in coconut, palm and kernel oil. Some parameters of

analyzing biodiesel in Gas Chromatography are given in table 5.3.

For analysis of contaminants in biodiesel described earlier, derivatisation during

sample preparation is essential as this improves the irregularity in to procedure by

showing excellent peak shapes, good recoveries and low detection limits. Some

derivatising agents used include N, O-bis trimethylsilyltrifluoroacetamide (BSTFA),

N-Methyl –N-trimethylsilyltrifluoroacetamide (MSTFA). 1,4-butanediol and 1,2,4-

butanetriol have been used as internal standards for free glycerol detection.

Table 5.3. Summary of Some Parameters for Analysing Biodiesel in Gas

Chromatography.

Column Details

l x id x ft (phase)

Detector*

Temperature

(˚C)

Injector

Temperature

(˚C)

Oven Program

30m x 0.25mm x 0.25µm

(Polyethylene glycol)

250 250 165-180˚C (4 ˚C/min)

180-200˚C (5 ˚C/min)

200-260˚C (15

˚C/min)

260˚C (2 min)

25m x 0.53mm x 1µm

(acidified polyethylene glycol)

- - 180-200˚C (4 ˚C/min)

25m x 0.32mm x 0.52 µm (5%

diphenyl and 95% dimethyl

polysiloxane)

280 250 150-225˚C (5 ˚C/min)

30m x 0.32mm x 1µm 300 300 190-215˚C (6 ˚C/min)

215-300˚C (4 ˚C/min)

* Flame Ionization Detector

Atmospheric Pressure Chemical Ionisation Mass Spectrometry (APCI-MS) detection

technique when coupled with reverse phase HPLC was found to be most suitable for


93

analysis of biodiesel. This was reported by Holcapek et. al (1999) after an extensive

study on different detectors used with HPLC analytical technique. UV detection at

205nm and Evaporative Light Scattering Detectors (ELSD) were also explored.

Gel Permeation Chromatography (GPC) or gel filtration chromatography, also known

as Size Exclusion Chromatography (SEC) employees a separation mechanism

technique. Separation of analyte occurs according to its hydrodynamic volume or

hydrodynamic diameter. It encompasses similar instrumentation set up to HPLC

(technique by physical state of mobile phase) except the nature of the column. More

than one column can be used for better separation96. Table 5.4 contains a summary of

some analytical condition used during HPLC analysis.

Table 5.4. Summary of Some Parameters for Analysing Biodiesel by High

Performance Liquid Chromatography97.

Column Details

l x id ( TM)

Flow

Rate

(ml/min)

Injection

Loop (µl)

Temperature

(˚C)

Mobile Phase

250mm x 4.6mm (STRODS-II) 1 - 40 Methanol

250mm x 4mm (LiChro CART

RP-C18)

1 10 - Hexane:isopropano

l:methanol

300mm x 7.8mm (GPC-

Styragel)

1 500 - Toluene

300mm x 7.5mm (GPC-

Styragel)

- 35-40 tetrahydrofuran

So far in this research the suitable raw materials have been identified (chapter 3) and

these have been used to synthesize biodiesel through the various tranesterification

methods described in chapter 4. After the purification process these samples are now

ready for chemical and physical analysis.


94

This chapter greatly investigates Gas Chromatography and Gel Permeation

Chromatography as suitable chemical analysis for biodiesel analysis in Fiji. These

methods are greatly explored in the next section. It discusses the analysis of methyl

and ethyl ester (biodiesel) followed by analysis of mono-, di- and triglycerides

(contaminants). Gas Chromatography – Mass Spectrocopy analysis was carried

overseas for confirmation of the biodiesel composition. The viscosity of these

biodiesel samples is also determined as a physical parameter. The pros and cons of

GC and GPC are later discussed.


95

5.2 METHYL AND ETHYL ESTERS (BIODIESEL)

5.2.1 Gas Chromatography – Flame Ionisation Detector (FID)

5.2.1.1 Methodology

Sample preparation

250 mg of biodiesel sample was accurately weighed on an analytical balance in two

10ml screw cap glass vial. 5 ml of freshly prepared 10mg/ml methyl heptadecanoate

solution (internal standard) which was prepared in a 50ml volumetric flask by

dissolving 500mg of methyl heptadecanoate in heptane and diluting up to the mark

was then added to one vial So. To the other vial added 5ml of heptane was added and

this was labeled Rf. The vials were closed and shaken homogeneously after which 1µl

of this solution was analyzed for its ester content in gas chromatography. After each

injection the syringe was washed with heptane and then washed with the sample

several times. Washing was carried out repeatedly to ensure that the syringe is clean

and there is no contamination. This procedure was carried out for methyl and ethyl

esters of waste oil and methyl and ethyl ester of coconut oil analysis.

Feedstock such as animal fat and lauric oils may contain naturally occurring

heptadecanoate acids (C17:0). In a recent study, Schober et al98 discovered that, when

esterified, the peaks areas of heptadecanoate esters in biodiesel samples interfere with

the internal standard resulting in lowering of the real ester content in the sample. Also,

the shorter chain fatty acid esters from caprylic (C8:0) and lauric (C12:0) acid are

excluded from the calculation according to the European standards EN 14103 method.

Thus the method described is a modification of EN 14103 method that has been


96

recommended for biodiesel derived from animal fat and lauric oil such as coconut oil

and some waste oil.

Chromatographic analysis

Determination of ester content of the samples were analysed by gas chromatography

technique on a Clarus 500 GC apparatus equipped with Total Chrom version 6.2.0

software. A non-bonded cyanosilicone phase capillary column was used.

Table 5.5 Gas Chromatography FID Instrumentation Condition for Biodiesel

Analysis

Column: SP2330 (supelco)

60m x 0.32mm ID x 0.20µm film.

Cat. No: 2-4074

Oven: Initial temperature: 200°C,

Initial hold: 0.00 min

Equiliberation time: 2.00min

Ramp 1: 2.0 °C/min to 210°C, hold for 10.00 min


Total run time: 25.00 min

Carrier: Nitrogen at 10.8 psi Head pressure

Injector: Split mode

Temperature: 290°C

Injection volume 1 µl

Detector:

Flame Ionization Detector

Temperature: 250°C

Spilt flow ratio: 100:1

Split flow rate: 71 ml/min


97

Expression of results

The ester content C is expressed as percentage (wt %) and is calculated using this

equation:

Where;

ΣA is the total peak area from the methyl ester C14 to that in C24:1,

AEI is the peak corresponding to methyl heptadecanoate in sample So,

AER is the peak corresponding to methyl heptadecanoate of the Rf sample,

CEI is the concentration (mg/ml) of methyl heptadecanoate solution being used,

VEI is the volume (ml) of the methyl heptadecanote solution being used,

W is the weight (mg) of sample.

C =( ) ( )

( ) 100××

×−

−−∑W

VC

AA

AAAEIEI

EREI

EREI


98

5.2.1.2 Results

Methyl esters of Coconut oil

Table 5.6 Calculation of the Percentage Methyl Ester in the Samples (GC-FID)

Samples

W mass of sample (mg)

∑∑∑∑A E

(∑A-Aei)/Aei

F (Cei x Vei)/W

E x F x 100* (%)

1 C001coco-2A-WBDM 252.30 140051.61 4.9093 0.1982 97.2919 2 C001coco-2B-WBDM 253.30 144437.91 4.6349 0.1974 91.4912 3 C001coco-1-WBDM 253.00 136726.27 4.6189 0.1976 91.2817






* The percentage is calculated based on the peaks identified in table A.28.


99

Ethyl esters of Coconut oil

Table 5.7 Calculation of the Percentage Ethyl Ester in the Samples (GC- FID)

Samples W mass of sample

(mg)

åA E (åA-

Aei)/Aei

F (Cei x Vei)/W

E x F x 100* (%)

1 C001coco-2A-WBDE 253.5 33452.31 0.2703 0.1972 5.3310

2 C001coco-2A-WBDE-salt 252.3 35404.15 0.3557 0.1982 7.0492

3 C001coco-2B-WBDE 253.6 29217.72 0.0292 0.1972 0.5762

4 C001coco-2B-WBDE-salt 254.7 27367.37 0.0315 0.1963 0.6184

5 C001coco-3-WBDE 251.5 131553.15 3.8810 0.1988 77.1579

6 C001coco-3-WBDE-salt 250.6 128503.41 4.5513 0.1995 90.8073

7 C021coco-2A-WBDE 252.1 28378.31 0.0678 0.1983 1.3444

8 C021coco-2A-WBDE-salt 251.3 29709.83 0.0809 0.1990 1.6103

9 C021coco-2B-WBDE 254.9 24894.99 0.0444 0.1962 0.8706

10 C021coco-2B-WBDE-salt 252 28859.51 0.0429 0.1984 0.8519

11 C021coco-3-WBDE 251.4 119417.17 3.3303 0.1989 66.2348

12 C021coco-3-WBDE-salt 254 97876.76 2.8172 0.1969 55.4564

13 C031coco-2A-WBDE 253.4 28766.12 0.0804 0.1973 1.5856

14 C031coco-2A-WBDE-salt 250.6 28006.84 0.0974 0.1995 1.9437

14 C031coco-2B-WBDE 255.6 24074.63 0.0307 0.1956 0.6011

15 C031coco-2B-WBDE-salt 251.3 27534.14 0.0253 0.1990 0.5036

16 C031coco-3-WBDE 254 128703.70 4.6807 0.1969 92.1398

17 C031coco-3-WBDE-salt 254.7 102474.90 2.8173 0.1963 55.3067

18 C002coco-2A-WBDE 252.8 24301.17 0.1385 0.1978 2.7384

19 C002coco-2A-WBDE-salt 252.6 25664.37 0.1478 0.1979 2.9261

20 C002coco-2B-WBDE 254.6 28104.67 0.0280 0.1964 0.5497

21 C002coco-2B-WBDE-salt 253.5 28611.76 0.0391 0.1972 0.7719

22 C002coco-3-WBDE 254.2 84947.90 3.1197 0.1967 61.3630

23 C002coco-3-WBDE-salt 252.7 86142.09 2.3411 0.1979 46.3227

24 C022coco-2A-WBDE 251.8 30447.54 0.2728 0.1986 5.4176

25 C022coco-2A-WBDE-salt 254.3 32147.52 0.2858 0.1966 5.6189

26 C022coco-2B-WBDE 251.3 28823.51 0.0550 0.1990 1.0943

27 C022coco-2B-WBDE-salt 250.5 25173.87 0.0741 0.1996 1.4793

28 C022coco-3-WBDE 250.5 102020.43 2.4436 0.1996 48.7754

29 C022coco-3-WBDE-salt 251.2 73587.66 3.1845 0.1990 63.3852

30 C032coco-2A-WBDE 251.2 42506.32 0.6173 0.1990 12.2873

31 C032coco-2A-WBDE-salt 254.3 28096.31 0.5914 0.1966 11.6276

32 C032coco-2B-WBDE 251 28576.43 0.3510 0.1992 6.9926

33 C032coco-2B-WBDE-salt 252 29241.07 0.3301 0.1984 6.5489

34 C032coco-3-WBDE 253.5 74071.81 2.6956 0.1972 53.1683

35 C032coco-3-WBDE-salt 251.1 71051.09 3.1011 0.1991 61.7512 * The percentage is calculated based on the peaks identified in table A.29.


100

Methyl esters of Waste Oil

Table 5.8 Calculation of the Percentage Methyl Ester in the Samples (GC-FID)

Samples

W mass of sample

(mg)

∑∑∑∑A E

(∑A-Aei)/Aei

F (Cei x Vei)/W

E x F x 100* (%)

1 W001p-1-WBDM 250.40 4289.25 1.4507 0.1997 28.9672 2 W021p-1-WBDM 250.20 5784.92 1.4115 0.1998 28.2072 3 W031p-1-WBDM 252.60 5417.45 1.4550 0.1979 28.8007

4 W002s-1-WBDM 254.90 4492.35 1.5033 0.1962 29.4881 5 W022s-1-WBDM 251.40 6015.81 1.2644 0.1989 25.1475 6 W032s-1-WBDM 251.90 10317.08 2.9247 0.1985 58.0521

7 W003s-2A-WBDM 254.20 3788.11 1.4421 0.1967 28.3657 8 W023s-1-WBDM 252.90 4643.76 1.3625 0.1977 26.9374 9 W033s-2A-WBDM 251.90 4599.13 1.2861 0.1985 25.5289

* The percentage is calculated based on the peaks identified in table A.30.

Ethyl esters of waste oil

Table 5.9 Calculation of the Percentage Ethyl Ester in the Samples (GC-FID)

Samples

W mass of sample

(mg)

∑∑∑∑A E

(∑A-Aei)/Aei

F (Cei x Vei)/W

E x F x 100* (%)

1 W001p-3-WBDE 252.50 4428.10 1.5205 0.1980 30.1096

2 W021p-3-WBDE 253.70 2698.43 1.4579 0.1971 28.7328

3 W031p-3-WBDE 251.30 2954.77 1.5481 0.1990 30.8017

4 W002s-3-WBDE 250.90 2509.48 1.4281 0.1993 28.4594

5 W022s-3-WBDE 252.50 2714.15 1.3256 0.1980 26.2497

6 W032s-3-WBDE 252.60 2664.04 1.3066 0.1979 25.8624

7 W003s-3-WBDE 254.00 3656.53 1.5167 0.1969 29.8558

8 W023s-3-WBDE 254.50 3848.14 1.4248 0.1965 27.9925

9 W033s-3-WBDE 253.70 3055.85 1.3181 0.1971 25.9774 * The percentage is calculated based on the peaks identified in table A.31.


101

5.2.1.3 Discussion

The following ester components were identified from the coconut oil esters prepared

using different experimental methods:

Caprylic acid methyl ester (C8:0), Capric acid methyl ester (C10:0), Lauric acid

methyl ester (C12:0), Myristic acid methyl ester (C14:0), Palmitic acid methyl ester

(C16:0), Stearic acid methyl ester (C18:0), Oleic acid methyl ester (C18:1), Linoleic

acid methyl ester (C18:2). These esters were used in calculating the percentage yield.

Similarly, the ethyl forms of these esters were also identified in ethyl esters of

coconut oil samples produced.

The analytical methodology given in the gas chromatography instrumentation

standard methods are modified as it is not suitable for kennel or palm oil ester.

Temperature programming has been employed to distinctly separate and prevent

overlap of low carbon ester peaks present in coconut oil. Columns with different

polarity were also investigated. Several trials of different temperature programming

methods have been done and the most efficient methodology was used for analysis.

Adaptation of other GC instrumentation methods for biodiesel99 and its

contaminant100 analysis proved to be useful.

Also note that naturally occurring methyl heptadecanoate does not interfere with other

ester peaks present in coconut oil biodiesel samples as seen figure 5.2 chromatogram

A and B


102

4

6

8

10

12

14

16

18

20

8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0 12.5

10.74

10.36

9.82

11.21 11.61 12.24

9.45

9.22

9.06

Chromatogram A: C002coco-2A-WBDM-So

4

6

8

10

12

14

16

18

20

22

24

8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0 12.5

8.919.07

9.29

9.65

10.20

11.0311.45

12.06

Chromatogram B: C002coco-2A-WBDM-Rf Figure 5.2 Purified Coconut Oil Methyl Ester Synthesized Using Method 2A.

Chromatogram B shows absence of naturally occurring methyl heptadecanoate (MH) in

sample c.f chromatogram A (spiked with MH).

As there was not any methyl heptadecanoate naturally occurring in the sample, the

correction by subtraction as documented in the method was not carried out.

Methyl heptdecanoate


103

Table 5.10 Percentage Concentration of Methyl Esters Analysed by GC FID

Methyl ester Method Range (%) Median (%) Waste oil (Methyl

oleate)

1 28.49-25.15 28.21

Coconut oil (Methyl

laurate)

1 122.51-91.28 96.22

2A 116.71-91.43 98.39

2B 112.82-81.80 94.49

The retention times of the esters used for identification of the respective peaks are

given in the Appendix

Figure 5.3 Percentage of Methyl Laurate in Coconut Oil Methyl Ester (GC-FID)

When comparing the coconut oil esters from different methods of production,

synthetic method 2A indicated to be a better method in terms of the median

percentage of ester . However, method 2A has a wider percentage range (116.71%-

91.43%) that overlaps with the percentage range obtained using synthesis method 1

96.22

98.39

94.49

92

93

94

95

96

97

98

99

Est

er C

onte

nt (

%)

1 2A 2B

Biodiesel Synthetic Methods

Ester Content of Biodiesel in Coconut Oil Methyl Es ters


104

(122.51%-91.28%). Thus, method 1 is as effective as 2A. Synthetic method 2B has a

slightly lower yield comparatively.

Methyl esters from waste oil showed percentage yield from 28.49%-25.15%. More

ester constituents were considered while calculating these values that makes it

incomparable with coconut oil methyl esters prepared using different methods.

However, it still indicates a very low yield even after considering the unidentified

peaks.

Figure 5.4 Purified waste oil methyl ester synthesized using method 3 (GC-FID).

Table 5.11 Percentage Concentration of Ethyl Esters Analysed by GC-FID

Ethyl ester Method Range (%) Median (%)

Ethyl oleate 3 30.80-25.86 28.46

Ethyl laurate 3 92.14-46.32 61.56

2A 12.29-1.34 4.13

2B 6.99-0.50 0.81

5.00

5.10

5.20

5.30

5.40

5.50

5.60

7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0 12.5

7.72 8.16

8.83

9.79

10.16

10.74


105

4.130.82

61.56

0

10

20

30

40

50

60

70

Est

er C

onte

nt (

%)

2A 2B 3


Ester Content of Biodiesle in Coconut Oil Ethyl Est ers

Figure 5.5 Percentage of Methyl Laurate in Coconut Oil Ethyl Ester (GC-FID)

For ethyl ester, similar comparison is done to determine the best method of biodiesel

synthesis. Method 3 is the best of the other 2 methods employed (method 2A and

method 2B). The percentage yields of ester obtained are lower than methyl esters for

the same oil. However, unlike coconut oil ethyl esters, waste oil ethyl esters show

percentage yield to be consistence with its methyl esters.

There was no difference in the composition of esters observed with coconut oil ethyl

esters when washed with saline water as expected. Saline water can be used

efficiently in the purification process as described in chapter 4. This can be done

without compromising the quality of biodiesel.


106

Figure 5.6 Purified Coconut Oil Ethyl Ester (GC-FID) showing similar profile.

Purification by salt water and distilled water show similar profile

6

8

10

12

14

16

7.8 8.0 8.2 8.4 8.6 8.8 9.0 9.2 9.4 9.6 9.8 10.0 10.2 10.4 10.6 10.8 11.0 11.2 11.4 11.6 11.8

8.188.34

8.57

8.96

9.57

10.5710.96 11.63

Chromatogram: C001coco-3-WBDE-salt So


107

5.2.2 Gel Permeation Chromatography

5.2.2.1 Methodology101

Sample preparation

300mg of biodiesel sample was weighed out on an analytical balance in a 10ml screw

cap vial and diluted with 5ml HPLC grade tetrahydrofuran. The solution was mixed

well after closing the vial and filtered using a glass syringe having a 0.2µm nylon

syringe filter.10µl of the filtered solution was then analyzed in gel permeation

chromatography (GPC) instrument. Tetrahydrofuran was filtered with 0.45µm nylon

filter paper before use. All glassware used for this analysis was made of glass.

Standard preparation

The respective methyl and ethyl ester standards were quantified in coconut oil and

waste oil. Methyl ester standards included methyl oleate (waste oil) and methyl

laurate (coconut oil) while Ethyl ester standards were Ethyl Oleate (waste oil) and

Ethyl Laurate (coconut oil). These standards were prepared in different

concentrations (table 5.12 – table 5.15) and 10µl of each were analyzed in a GPC

system described below.

A calibration curve was plotted using the peak area of these standards versus its

concentration to determine the concentration of methyl the respective methyl and

ethyl ester in coconut and waste oil biodiesel prepared using the various synthetic

methods in this research.


108

Table 5.12 Peak Area versus Concentration of Methyl Oleate

Concentration (mg/ml) Area (V*sec)

26.0 1400000

25.5 1360002

22.0 1161610

19.5 1003473

16.0 862090

13.5 720942

Figure 5.7 Calibration Curve of Methyl Oleate

Table 5.13 Peak Area versus Concentration of Methyl Laurate


10 217013

12 247119

14 279945

16 323461

18 370137

20 403793

y = 53679x - 11267

R2 = 0.9957

0

200000

400000

600000

800000

1000000

1200000

1400000

1600000

0 5 10 15 20 25 30

Concentration (mg/ml)

Are

a (M

V)


109

Figure 5.8 Calibration Curve of Methyl Laurate

Table 5.14 Peak Area versus Concentration of Ethyl Oleate


20 1068207

18 961203

16 853980

14 743750

12 639060

10 540325

Figure 5.9 Calibration Curve of Ethyl Oleate

y = 19235x + 18382

R2 = 0.9946

050000

100000150000200000250000300000350000400000450000

0 5 10 15 20 25


Are

a (M

V)

y = 53087x + 4787

R2 = 0.9997

0

200000

400000

600000

800000

1000000

1200000

0 5 10 15 20 25


Are

a (M

V)


110

Table 5.15 Peak Area versus Concentration of Ethyl Laurate


0.5 7988

3.5 60063

6.5 99945

9.5 160007

12.5 210232

15.5 260371

17.5 300012

Figure 5.10 Calibration Curve of Ethyl Laurate


The biodiesel samples were analyzed for its ester content and contaminants such as

glycerides using size exclusion chromatography. The GPC system consists of Water

1515 isocratic HPLC pump, Waters 717 plus Autosampler, Waters 2414 Refractive

Index (RI) Detector and Breeze software.

y = 17108x - 3133.5

R2 = 0.9985

0

50000

100000

150000

200000

250000

300000

350000

0 5 10 15 20


Are

a (M

V)


111

Table 5.16 Gel Permeation Chromatography instrumentation conditions for

Biodiesel analysis

Column Two phenogel 50 Å (phenomenex) connected in series

300mm x 7.8mm x 5 microns

Mobile phase Tetrahydrofuran (HPLC grade)

Flow rate 1 ml/min at room temperature.

RI detector Temperature 28.7 °C

Sensitivity 4


Run time 22 min


112

5.2.2.2 Results

Methyl esters of Waste oil

Table 5.17 Concentration of Methyl Oleate in Waste Oil Biodiesel Samples (GPC)

Sample Retention

time (min)

Methyl

Oleate

peak area

(V*sec)

A Concentration

of Methyl oleate

(mg/ml)

B mass of

sample

[(A x

5ml*)/B] x

100 (%)

W001p-1-WBDM 13.433 1263283 23.324 303.5 38.4253

W021p-1-WBDM 13.44 1247793 23.036 304.1 37.8750

W031p-1-WBDM 13.388 1215638 22.437 303.3 22.5532

W002s-1-WBDM 13.434 1314988 24.287 304.7 39.8545

W022s-1-WBDM 13.386 1177009 21.717 300.4 36.1467

W032s-1-WBDM 13.389 1040084 19.166 300.9 31.8480

W003s-1-WBDM 13.387 1258811 23.241 301.7 38.5164

W023s-1-WBDM 13.426 1283123 23.694 304.9 38.8549

W033s-1-WBDM 13.419 1240500 22.899 301.4 37.9889

* 5ml is the volume of THF

Note: all samples were prepared using Acid pretreatment methodology.


113

Methyl esters of Coconut oil

Table 5.18 Concentratrion of Methyl Laurate in Coconut Oil Biodiesel Samples

(GPC)

Sample Methyl

Laurate

peak

area

B

Mass of

samples

(g)

A

Concentration of Methyl

Laurate (mg/ml)

[(A x 5ml*)/B] x 100

(%)

2A 2B 1 2A 2B 1

C001coco-2A-WBDM 349482 301.6 17.213 28.537

C001coco-2B-WBDM 329675 305.1 16.184 26.522

C001coco-1-WBDM 343967 301 16.927 28.117

C021coco-2A-WBDM 331957 300.5 16.302 27.125

C021coco-2B-WBDM 331914 302.7 16.300 26.925

C021coco-1-WBDM 347752 301.5 17.123 28.397

C031coco-2A-WBDM 343272 304.8 16.891 27.529

C031coco-2B-WBDM 324389 302.8 15.909 26.270

C031coco-1-WBDM 350460 303.1 17.264 28.479

C002coco-2A-WBDM 313523 302.5 15.344 25.362

C002coco-2B-WBDM 289013 304.3 14.070 23.118

C002coco-1-WBDM 338022 302.1 16.618 27.504

C022coco-2A-WBDM 336835 300.7 16.556 27.529

C022coco-2B-WBDM 332735 301.3 16.343 27.120

C022coco-1-WBDM 340914 304.9 16.768 27.498

C032coco-2A-WBDM 346318 301.8 17.049 28.245

C032coco-2B-WBDM 342281 302.8 16.839 27.806

C032coco-1-WBDM 342763 301.3 16.864 27.986

2A (One Step Base Transesterification), 2B (Two Step Base Transesterification) and 1 (Acid

pretreatment, one-step basic transesterification) are synthetic methods for biodiesel production used

in this research (refer to chapter 4).


114

Ethyl esters of Waste oil

Table 5.19 Concentration of Ethyl Oleate in Waste Oil Biodiesel Samples (GPC)

Sample Retenti

on time

(min)

Ethyl

Oleate

peak area

A Concentration

of Methyl oleate

(mg/ml)

B mass

of

sample

[(A x 5ml*)/B]

x 100 (%)

W001p-3-WBDE 13.05 987922 18.519 302.6 30.6003

W021p-3-WBDE 13.012 579300 10.822 301.4 17.9531

W031p-3-WBDE 13.019 756459 14.159 304.9 23.2195

W002s-3-WBDE 13.022 637504 11.918 301.6 19.7588

W022s-3-WBDE 12.996 788110 14.755 302.8 24.3650

W032s-3-WBDE 12.984 703472 13.161 302.0 21.7900

W003s-3-WBDE 13.007 934246 17.508 303.9 28.8059

W023s-3-WBDE 13.034 1028822 19.290 305.0 31.6225

W033s-3-WBDE 13.064 912674 17.102 303.4 28.1837

* 5ml is the volume of THF.

All samples were prepared using synthetic method 3 (Base Neutralisation One Step Base

Transesterification).


115

Ethyl esters of Coconut oil

Table 5.20 Concentratrion of Ethyl Laurate in Coconut Oil Biodiesel Samples

(GPC)

Sample Ethyl Laurate

peak area

Concentration of Ethyl Laurate (mg/ml)

B mass of

sample

[(A x 5ml*)/B] x 100 (%)

2A 2B 3 2A 2B 3 C001coco-2A-WBDE 30942 1.625 301.8 2.693 C001coco-2A-WBDE-salt 33394 1.769 305.8 2.892 C001coco-2B-WBDE 14389 0.658 301.6 1.603 C001coco-2B-WBDE-salt 19847 0.977 302 1.618 C001coco-3-WBDE 276079 15.954 305.2 26.137 C021coco-2A-WBDE 23409 1.185 302.6 1.958 C021coco-2A-WBDE-salt 23539 1.193 304.7 1.957 C021coco-2B-WBDE 19952 0.983 302.5 1.625 C021coco-2B-WBDE-salt 20293 1.003 303.4 1.653 C021coco-3-WBDE 197916 11.096 301.4 18.888 C021coco-3-WBDE-salt 192957 11.385 302.6 18.334 C031coco-2A-WBDE 18715 0.911 305.5 1.556 C031coco-2A-WBDE-salt 15597 0.951 302.9 1.203 C031coco-2B-WBDE 17369 0.832 305.5 1.362$ C031coco-2B-WBDE-salt 19395 0.729 302.9 1.503 C031coco-3-WBDE 179787 10.326 302.9 17.045 C031coco-3-WBDE-salt 186599 10.724 301.2 17.802 C002coco-2A-WBDE 10650 1.439 302.2 0.727 C002coco-2A-WBDE-salt 22554 1.135 304.1 1.866 C002coco-2B-WBDE 18092 0.874 302.5 1.445 C002coco-2B-WBDE-salt 17828 0.859 302.3 1.421 C002coco-3-WBDE 176481 10.133 304.3 16.649 C002coco-3-WBDE-salt 180224 10.351 302.3 17.121 C022coco-2A-WBDE 22635 1.140 305.5 1.866 C022coco-2A-WBDE-salt 25336 1.298 302.8 2.143 C022coco-2B-WBDE 21355 1.065 303.5 1.755 C022coco-2B-WBDE-salt 18089 0.874 303.9 1.438 C022coco-3-WBDE 169043 9.698 302.6 16.024 C022coco-3-WBDE-salt 175800 10.093 304.5 16.573 C032coco-2A-WBDE 50912 2.793 302 4.624 C032coco-2A-WBDE-salt 45798 2.494 302.8 4.118 C032coco-2B-WBDE 21357 1.065 301 1.769 C032coco-2B-WBDE-salt 21918 1.098 300.7 1.826 C032coco-3-WBDE 156865 8.986 303.9 14.784 C032coco-3-WBDE-salt 166676 9.559 304.5 15.697

2A (One Step Base Transesterification), 2B (Two Step Base Transesterification) and 3 (Base

Neutralisation One Step Base Transesterification) are synthetic methods for biodiesel production

used in this research (refer to chapter 4).


116

5.2.2.3 Discussion

The ester content in biodiesel from waste oil and coconut oil is quantified as a single

component unlike Gas Chomatography. The analytical standards used are: methyl

oleate and ethyl laurate in biodiesle from coconut oil and methyl oleate and ethyl

oleate in waste oil biodiesel. The esters of the fatty acid in the lipid raw material will

be present in similar percentage composition as its fatty acids in oil. The

transesterification of all fatty acids into esters occur proportionately which makes it

correct to quantify an ester and use it for comparing synthetic method of biodiesel

production. These standards have been used to determine the most efficient method of

producing biodiesel.

Methanol and ethanol as solvents cannot be used for comparative purposes as they

both have different rate of reaction with the catalyst (acidic and alkali) for biodiesel

production

Methyl Esters

Table 5.21 Percentage Concentration of Methyl Esters Analysed by GPC

Methyl ester Method Range (mg/ml) Median (mg/ml)

Waste oil (Methyl

oleate)

1 22.55-39.85 37.99

Coconut oil (Methyl

laurate)

1 27.50-28.48 28.05

2A 25.36-28.54 27.53

2B 23.12-27.81 26.72


117

Figure 5.11 Percentage of Methyl Laurate in Coconut Oil Methyl Ester (GPC)

The table above discusses methyl esters from coconut oil and waste oil produced from

different esterification methods. For waste oil the major component quantified was

Methyl oleate and Methyl laurate in coconut oil.

Similar to results obtained from Gas Chromatography analysis, all synthetic method

were found to be of similar effectiveness with slight variation relative to each other.

Method 1 had the highest percentage median, followed by 2A than synthetic method

2B.

Lower production of ester in methodology 2A (one step base transesterfication) and

2B (two step base transesterification) resulted from formation of soap due to presence

of high free fatty acid content in lipid feedstock prior to transesterification reaction

also hindered the reaction. Whereas in method 1, high FFA content was pretreated

with acid catalyst and all products (water) were removed by washing with alcohol

before tranesterification. This step made the lipid feedstock more ready for

27.53

26.72

28.05

26

27

27

28

28

29

Est

er C

onte

nt (

%)

2A 2B 1


Ester Content of Coconut Oil Methyl Esters


118

transesterification reaction as the catalyst would react with more glycerides and

convert them into ester.

Comparing method 2A and 2B, 2A was found to be the better method. Partial addition

of catalyst mixture hinders higher ester formation.

Ethyl Esters

Table 5.22 Percentage Concentration of Ethyl Esters Analysed by GPC

Ethyl ester Method Range (mg/ml) Median (mg/ml)

Waste oil (Ethyl

oleate)

3 17.95-31.62 24.37

Coconut oil (Ethyl

laurate)

3 14.78-26.14 17.04

2A 0.73-1.82 1.96

2B 1.36-4.62 1.61

Figure 5.12 Percentage of Ethyl Laurate in Coconut Oil Ethyl Ester (GPC)

2.24 2.36 1.59 1.58

18.25 17.11

0.00

5.00

10.00

15.00

20.00

Est

er C

onte

nt (

%)

2A

2A sa

lt 2B

2B sa

lt 33

salt


Ester Content of Coconut Oil Ethyl Esters


119

The table above clearly indicates that methods 3 is a better method to use for ethyl

ester production. Relatively, method 2A was found to be better than 2B as also seen in

methyl ester analysis.

It was also observed that the samples washed with salt had greater concentration of

ethyl laurate as compare to samples washed with distilled water.

Methyl Ester versus Ethyl Ester

When comparing the analysis of both esters from the sample oil, it was observed that

the quantity of methyl esters were greater than its ethyl esters under the same

synthetic method and analysis condition. This was observed as the solubility of

methanol with oil is better than ethanol and oil.

When biodiesel was produced from the same type of sample oil (and keeping the

synthetic methods and analysis conditions unaltered), methyl esters were found to be

formed in greater quantity than ethyl esters. This is primarily due to oil being more

miscible in methanol than with ethanol.

The catalyst mixture (bound to the alcohol) is able to interact and give a faster

reaction time, which in turn promotes a greater yield.

In ethanol the oil is less miscible, thus there is less reactants available in a reactive

state. The result is a reduced yield.


120

5.3 MONO-, DI- AND TRIGLYCERIDES (FREE AND

TOTAL GLYCERIDES)

5.3.1 Gas Chromatography

5.3.1.1 Methodology102

Sample preparation

Accurately weighed 100mg of biodiesel sample in a 10ml glass vial. To this 80µl of

internal standard 1 (1mg/ml butanetriol), 100µl of internal standard 2 (8mg/ml 1,2,3-

tricaproylglycerol) and 100µl of derivatising agent: N-methyl, N-

trimethylsilyltrifluoroacetamide (MSTFA) was added using micropipettes. Internal

standard 1 was intended for free glycerol determination and internal standard 2 was

for determining mono-,di- and triglycerides. The vial was quickly closed and shaken

vigorously then left at room temperature for 45minutes before adding 8ml heptane to

it. 5µl of this was then analyzed in gas chromatography instrument equipped with FID

detector. All glassware was dry and clean before use and contact to moisture was

avoided.

Preparation of standards and internal standards

Internal standard 1 (IS #1) (1mg/ml): 50mg of 1,2,4 butanetriol was dissolved in

pyridine and made up to the mark in a 50ml glass stoppered volumetric flask. Inverted

the flask to ensure homogenous mixing of solution.


121

Internal standard 2 (IS #2) (8mg/ml): 80mg of 1,2,3-tricaprroylglycerol was

dissolved in a 10ml glass stoppered volumetric flask and made up o the mark with

pyridine. Inverted the flask to ensure homogenous mixing of solution.

Glycerol (0.5mg/ml): dissolved 50mg of glycerol in a 10ml volumetric and made up

to the mark with pyridine. 1 ml of this solution was transferred into another 10ml

glass stoppered volumetric flask and diluted up to the mark. Inverted the flask to

ensure homogenous mixing of solution.

Glyceride (5mg/ml): Prepared 5mg/ml solutions of mono, di and triglyceride

standards. Lauric acid glycerides and oleic acid glycerides were used to prepare

standards for coconut oil and waste oil. 50mg of each glycerides were weighed out

separately in 10ml glass stoppered volumetric flasks and made up to the mark with

pyridine. Inverted each flask to ensure homogenous mixing of solution.

Calibration solutions

Composition of glycerides and internal standards was mixed to prepare the calibration

solutions in 10ml glass vials. The volumes of each solution are given in the table

below.

Table 5.23 Glycerides Calibration solutions for contaminants in biodiesel from

waste oil (GC-FID)

Vial 1 Vial 2 Vial 3 Vial 4

µl of glycerol solution 10 40 70 100

µl of monolein solution* 50 120 190 250

µl of diolein solution* 10 40 70 100

µl of triolein solution* 10 30 60 80

µl of IS #1 solution 80 80 80 80

µl of IS #2 solution 100 100 100 100

• mono-, di- and trilauric solutions were used when preparing calibration solution for contaminants in coconut oil .


122

To each of the four calibration solution vials, 100µl of derivatising agent MSTFA was

added using a micro pipette and vigorously shaken before storing it at room

temperature for 45 minutes for completion of derivatisation reaction. 8 ml of heptane

was then added to each vial and homogenously mixed. The derivatised calibration

solutions are only stable for a few hours thus freshly prepared samples were analyzed

quickly using gas chromatography.


The derivatised samples and calibration solution were ananlysed using gas

chromatography instrument, clarus 500, equipped with FID detector. The injection

syringe was made free of any contamination by washing it several times with heptane

and the sample to be injected. The conditions for analysis are given in the table below.

Table 5.24 Gas Chromatography (FID) Instrumentation Condition for Biodiesel

Contaminants Analysis

Column: ATTM –5MS(Alltech)









Carrier: Nitrogen at 10.8 psi


Temperature: 200°C


Detector:

Flame Ionization Detector

Temperature: 300°C


Split flow rate: 60.1 ml/min


123

5.3.1.2 Results and Dicussion

Quantification of bound and free glycerides could not be carried out as the

derivatising agent degraded. The peaks of the derivatising agent observed in the

chromatograms overlapped the peaks of the sample and the standards used in this

method. Thus the quantification of the bound and free glycerides was inhibited. It is

recommended to use other appropriate derivatising agent.

Derivatising Agent - MSTFA

MSTFA is a better derivating agent over other common silylating agents like BSTFA

as it requires no heating and complete derivatisation reaction occurs at room

temperature. Inert storage conditions were required for this reagent. MSTFA reagent

bottle was store in a desicator purged with nitrogen gas (N2) and the bottle was always

purged with N2 gas whenever it was opened and before recapping. Despite such

precautionary measures MSTFA degraded, resulting in numerous peaks through out

the chromatogram. MSTFA is also moisture sensitive and is unsuitable to be used for

analysis in a very humid environment. Such chemicals require special chambers (inert

gas) for sample preparation, thus is not recommended for use in tropical countries

without appropriate facilities.


124

5.3.2 Gel Permeation Chromatography

5.3.2.1 Methodology

Sample preparation

The procedure for the analysis of contaminant in biodiesel using GPC was the same as

GPC method for ester content101 determination see section 5.3.1.1. The standard

preparation for calibration were prepared according to the table below

Standard preparation

The respective glyceride standards were quantified in coconut oil and waste oil.

Monolien, Diolien, and Triolien standards represented the glycerides in waste oil.

Monolauric, Dilauric and trilauric standards represented the glyceride in coconut

oil. These standards were prepared in different concentrations (table 5.25 to table 5.30)

and 10ul of each were analyzed in a GPC system described below.

A calibration curve was plotted using the peak area of these standards versus its

concentration. It was used to determine the concentration of glycerides in the

respective biodiesel samples synthesized from coconut and waste oil.

Figure 5.13 Calibration Curve of Trilauric Acid

y = 19166x + 70.615

R2 = 0.9927

0

200

400

600

800

1000

1200

0.0000 0.0100 0.0200 0.0300 0.0400 0.0500 0.0600


Are

a (V

*sec

)


125

Table 5.25 Peak Area versus Concentration of Trilauric Acid

Concentration (mg/ml) Peak Area (V*sec)

0.0061 208

0.0177 384

0.0285 630

0.0387 779

0.0482 1020

Figure 5.14 Calibration Curve of Dilauric Acid

Table 5.26 Peak Area versus Concentration of Dilauric Acid


0.0061 117

0.0236 618

0.0400 1334

0.0552 1815

0.0696 2390

y = 36173x - 152.47

R2 = 0.9962

0

500

1000

1500

2000

2500

3000

0.0000 0.0200 0.0400 0.0600 0.0800


Are

a (V

*sec

)


126

Figure 5.15 Calibration Curve of Monolauric Acid

Table 5.27 Peak Area versus Concentration of Monolauric Acid


0.0306 1577

0.0708 2387

0.1084 3347

0.1436 4386

0.1767 5280

Figure 5.16 Calibration Curve of Trioliec Acid

y = 39842x - 165.89R2 = 0.9946

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0.0000 0.0100 0.0200 0.0300 0.0400 0.0500 0.0600


Are

a (V

*sec

)

y = 25704x + 670

R2 = 0.9951

0

1000

2000

3000

4000

5000

6000

0.0000 0.0200 0.0400 0.0600 0.0800 0.1000 0.1200 0.1400 0.1600 0.1800 0.2000


Are

a (V

*sec

)


127

Table 5.28 Peak Area versus Concentration of Trioliec Acid


0.0061 101

0.0177 561

0.0285 903

0.0387 1344

0.0482 1808

Figure 5.17 Calibration Curve of Dioliec Acid

Table 5.29 Peak Area versus Concentration of Dioliec Acid


0.0061 117

0.0236 830

0.0400 1873

0.0552 2685

0.0696 3595

y = 55425x - 336.47R2 = 0.9948

0

500

1000

1500

2000

2500

3000

3500

4000

0.0000 0.0200 0.0400 0.0600 0.0800


Are

a (V

*sec

)


128

Figure 5.18 Calibration Curve of Monoliec Acid

Table 5.30 Peak Area versus Concentration of Monoliec Acid


0.0305 1012

0.0708 2472

0.1084 3766

0.1436 4863

0.1767 6129

0.2125 7561

y = 35486x - 91.964

R2 = 0.9987

0

1000

2000

3000

4000

5000

6000

7000

8000

0 0.05 0.1 0.15 0.2 0.25

Concentration (mg/ml)A

rea

(V*s

ec)


129

5.3.2.2 Results

Mono, Di and Tri-glyceride in Waste Oil Methyl Esters

Table 5.31 Concentration of Bound Glycerides in Waste Oil Biodiesel Samples

Sample Glycerides

peak area

(V*sec)

B

Mass of

sample

A Concentration

of Bound

Glycerides

(mg/ml)

[(A x 5ml)/B] x

100

(%)

W001p-1-WBDM 14869 303.5 0.422 - 0.377 0.695 – 0.622

W021p-1-WBDM 23014 304.1 0.651 - 0.582 1.071 – 0.957

W031p-1-WBDM 5920 303.3 0.169 - 0.153 0.279 – 0.252

W002s-1-WBDM 29066 304.7 0.822 - 0.734 1.348 – 1.204

W022s-1-WBDM 23544 300.4 0.666 - 0.595 1.109 – 0.991

W032s-1-WBDM 14507 300.9 0.411 - 0.368 0.684 – 0.612

W003s-1-WBDM 24666 301.7 0.698 - 0.623 1.156 – 1.033

W023s-1-WBDM 36021 304.9 1.018 - 0.909 1.669 – 1.489

W033s-1-WBDM 40440 301.4 1.142 - 0.019 1.895 – 1.691

Note: all samples were prepared using Acid pretreatment methodology


130

Mono, Di and Tri-glyceride in Coconut Oil Methyl Esters

Table 5.32 Concentration of Bound Glycerides in Coconut Oil Biodiesel Samples

Sample Glycerides

peak area

(V*sec)

B

Mass of

sample

A

Concentration

of Bound

Glycerides

(mg/ml)

[(A x 5ml)/B] x

100

(%)

C001coco-2A-WBDM 36949 301.6 1.411 – 1.924 2.340 – 3.190

C001coco-2B-WBDM 59862 305.1 2.303 – 3.120 3.774 – 5.113

C001coco-1-WBDM

C021coco-2A-WBDM 51703 300.5 1.985 – 2.694 3.304 – 4.482

C021coco-2B-WBDM 79874 302.7 3.081 – 4.164 5.090 – 6.878

C021coco-1-WBDM

C031coco-2A-WBDM 25788 304.8 0.977 – 1.342 1.603 – 2.201

C031coco-2B-WBDM 119056 302.8 4.606 – 6.208 7.605 – 10.251

C031coco-1-WBDM

C002coco-2A-WBDM 146220 302.5 5.663 – 7.625 9.360 – 12.604

C002coco-2B-WBDM 267621 304.3 10.386 – 13.960 17.065 – 22.937

C002coco-1-WBDM

C022coco-2A-WBDM 47218 300.7 1.811 – 2.460 3.011 – 4.090

C022coco-2B-WBDM 111217 301.3 4.301 – 5.799 7.137 – 9.624

C022coco-1-WBDM 5979 304.9 0.207 – 0.308 0.339 – 0.506

C032coco-2A-WBDM 14026 301.8 0.520 – 0.728 0.861 – 1.206

C032coco-2B-WBDM 3084 302.8 0.094 – 0.157 0.155 – 0.260

C032coco-1-WBDM 10960 301.3 0.400 – 0.568 0.664 – 0.943


131

Mono, Di and Tri-glyceride in Waste Oil Ethyl Esters

Table 5.33 Concentration of Bound Glycerides in Waste Oil Biodiesel Samples

A

Concentration of

Bound Glycerides

(mg/ml)

B

Mass of

sample

(mg)

(A x 5ml)/B] x 100

(%)

W001p-3-WBDE 134994 3.807 – 3.392 302.6 6.290 – 5.605

W021p-3-WBDE 358596 10.108 – 9.005 301.4 16.768 – 14.938

W031p-3-WBDE 381059 10.741 – 9.568 304.9 17.614 – 15.691

W002s-3-WBDE 319819 9.015 – 8.031 301.6 14.946 – 13.315

W022s-3-WBDE 441287 12.438 – 11.080 302.8 20.538 – 18.296

W032s-3-WBDE 464014 13.079 – 11.651 302.0 21.653 – 19.289

W003s-3-WBDE 207861 5.860 – 5.221 303.9 9.642 – 8.590

W023s-3-WBDE 199744 5.631 – 5.018 305.0 9.232 – 8.226

W033s-3-WBDE 187175 5.277 – 4.702 303.4 8.697 – 7.749


132

Mono, Di and Tri-glyceride in Coconut Oil Ethyl Esters

Table 5.34 Concentration of Bound Glycerides in Coconut Oil Biodiesel Samples

Sample Ethyl Laurate

peak area

A Concentration of

Bound Glycerides (mg/ml)

B Mass of sample (mg)

[(A x 5ml)/B] x 100 (%)

C001coco-2A-WBDE 145630 5.640 – 7.595 301.8 9.343 – 12.582 C001coco-2A-WBDE-salt 153938 5.963 – 8.028 305.8 9.749 – 13.127

C001coco-2B-WBDE 136863 5.299 – 7.137 301.6 8.784 – 11.832 C001coco-2B-WBDE-salt 137703 5.331 – 7.181 302 8.826 – 11.889

C001coco-3-WBDE 42896 1.643 – 2.234 305.2 2.691 – 3.660 C021coco-2A-WBDE 142429 5.515 – 7.428 302.6 9.113 – 12.273

C021coco-2A-WBDE-salt 139779 5.412 – 7.289 304.7 8.881 – 11.962 C021coco-2B-WBDE 142005 5.499 –7.406 302.5 9.089 – 12.241

C021coco-2B-WBDE-salt 144977 5.614 – 7.561 303.4 9.252 – 12.460 C021coco-3-WBDE 59299 2.281 – 3.090 301.4 3.7840 – 5.126

C021coco-3-WBDE-salt 58722 2.258 – 3.060 302.6 3.732 – 5.057 C031coco-2A-WBDE 147954 5.730 – 7.716 305.5 9.378 – 12.628

C031coco-2A-WBDE-salt 137351 5.317 – 7.163 302.9 8.778 – 11.824 C031coco-2B-WBDE 152523 5.908 – 7.954 305.5 9.670 – 13.019








C022coco-3-WBDE-salt 74060 2.855 – 3.861 304.5 4.688 – 6.339 C032coco-2A-WBDE 136399 5.280 – 7.113 302 8.743 – 11.777

C032coco-2A-WBDE-salt 120304 4.654 – 6.273 302.8 7.685 – 10.359 C032coco-2B-WBDE 134972 5.225 – 7.039 301 8.680 – 11.692


C032coco-3-WBDE-salt 91628 3.539 – 4.777 304.5 5.811 – 7.844


133

5.3.2.3 Discussion

When using standards which are glycerides (mono-, di- and triglycerides) of high

purity, the peaks distinctly separates but this does not occur in biodiesel samples.

However, the mono-, di- and triglycerides overlap each other forming a clump of

peaks with slight bumps indicating each group of glycerides, see figure below. The

components are separated according to their molecular weight, eluting in a descending

order.

The negative peaks can be accounted for as components with the refractive index (RI)

less than that of the mobile phase (THF). These contaminants are likely to be ethanol,

methanol or water that was present in the reaction mixture.

The column used separates small organics (components of interest in biodiesel sample

analysed) with molecular weight exclusion limit between 100 - 3K. The molecular

weights of the components of interest to be analysed in coconut oil and waste oil

biodiesel are given in the table 5.35.

Table 5.35 Molecular weights of components in biodiesel samples analysed

Acylglyceride Esters

Monoglyceride Diglyceride Triglyceride Methyl Ethy l

Coconut oil (Lauric

acid/ester) 274.4 456.7 639.0 214.3 228.4

Waste oil

(Oleic acid/ester) 356.5 621.0 885.4 296.5 310.5

According to the column specification more resolution of peaks were expected.

However, the cluster of peaks observed was unavoidable with the existing setup. This

could be corrected by connecting more similar columns or columns with larger pore

size in series. In a research conducted by Arzamendhi G, et. al.103 resolution of


134

glyceride (contaminant) peaks in biodiesel was effective when using three columns in

series. Two columns of which were similar with the third one having a smaller pore

size.

The results obtained by analyzing the synthesized biodiesel samples were acceptable

and quantification of the characterized group (total glyceride) was possible.

Figure 5.19 GPC chromatogram of Coconut oil Biodiesel Sample

In coconut oil biodiesel, the glycerides are quantified as lauric acid: monolauric acid,

dilauric acid and trilauric acid and in waste oil biodiesel the glycerides are represented

as oleic acid glycerides. Its quantification is carried out using calibration method of

glycerides described in the methodology. Percentages of total glycerides are given as

a range which encompasses the minimum and maximum percentage that could be

present in the sample. The minimum percentage is calculated based on the calibration

of triglycerides which has the lowest response factor relative to its esters. The

maximum range is deduced from monoglycerides calibration with the highest

response factor relative to its esters. See table 5.35.

Triglyceride

Diglyceride

Monoglycerides


135

Table 5.36 Relative Response Factors of Glycerides to Esters.

Glycerides Relative to Ester Relative Response Fact or

Methyl Oleate 0.308 Trioleic Acid

Ethyl Oleate 0.310

Methyl Oleate 0.356 Dioleic Acid

Ethyl Oleate 0.359

Methyl Oleate 0.614 Monoleic Acid

Ethyl Oleate 0.619

1.571 Trilauric Acid Methyl Laurate

Ethyl Laurate 2.134

Methyl Laurate 0.884 Dilauric Acid

Ethyl Laurate 1.201

Methyl Laurate 2.375 Monolauric Acid

Ethyl Laurate 3.225

It should be noted that the percentage of glycerides are represented as the major fatty

acid component in the lipid raw material of biodiesel. Thus, these results are

comparable only within this thesis.

Figure 5.20 Percentage Concentration of Glyceride content in Coconut oil Methyl

Esters

4.02

7.99

0.61

012345678

Bou

nd G

lyce

rides

(%

)

2A 2B 1


Glyceride Content of Coconut Oil Methyl Esters


136

Acid pretreatment followed by base transesterification production process contains

the least glycerides relative to other biodiesel synthetic methods. These results were

as expected as free fatty acids are hydrolysed leaving high concentration of glycerides

for the next base transesterification process. As free fatty acids are removed, the

alkaline catalysts react with the glycerides to form esters in presences of alcohol.

Imperatively, methods 2A and 2B both result in higher glyceride content in the

biodiesel samples. This is due to high free fatty acid content in the lipid raw material

(coconut oil). Straight base tranesterification is this case would result is high

concentration of unreacted glycerides as seen. In method 2B where the phases (upper

biodiesel and lower glycerol layer) are allowed to separate and removed (intermediate

process), transesterification reaction is slowed down. In the intermediate process the

reaction vessel cools, separation occurs and vessel is reheated after adding the

remaining catalytic mixture. This reduces the efficiency of glyceride conversion to

esters.

Figure 5.21 Percentage Concentrations of Glycerides in Coconut Oil Ethyl Esters

10.77 10.49 10.71 10.96

5.31 5.68

0

2

4

6

8

10

12

Bou

nd G

lyce

rides

(%

)

2A

2A sa

lt 2B

2B sa

lt 33

salt


Glyceride Content of Coconut Oil Ethyl Esters


137

As observed in methyl esters samples of biodiesel, the percentage of glycerides in

ethyl ester samples produced from 2A and 2B was high relative to synthetic method 3

(Base Neutralisation – one step bse transesterification).

Method 3 had excess alkaline catalyst to neutralize the free fatty acids present in the

lipid raw material (coconut oil). The remaining catalysts reacted with the glycerides to

form esters. It can be seen that a higher percentage of glycerides have been converted

to esters via method 3 than 2A or 2B.

Another important experiment conducted was the effect of saline water washing of

biodiesel during purification process. It is clear from the results tha saline water

washing has no effect on reducing the glyceride content in the biodiesel samples.

Figure 5.22 Using Percentage Glyceride Content to Compare Different Synthetic

Methods.

The glyceride conversion into esters is more effective using methanol as alcohol

source as compared to ethanol.

1.04 0.61

13.17

5.31

0

5

10

15

Bou

nd

Gly

cerid

e (%

)

1 3


Glyceride Content in Biodiesel from Different Synthetic Methods

Waste Oil Biodiesel Coconut Oil Biodiesel


138

Method 3 - Base Neutralization (excess base), one step base transesterfication and

method 1 – Acid Pretreatment, one step base transesterification were found to be the

better methods for higher conversion of glycerides into esters. The effect of high free

fatty acid is seen in the figure above where the glyceride contents of Waste oil

biodiesel and coconut oil biodiesel is compared. Waste oil used to prepare the

biodiesel sample has a higher free fatty acid content as compare to coconut oil (lipid

source for coconut oil esters). In the samples from both the methods (1and 3) waste

oil has a lower conversion of glycerides to esters than coconut oil with a lower free

fatty acid value.


139

5.3.3 Gas chromatography – Mass Spectrometry

5.3.3.1 Methodology

Sample preparation

1 µl of biodiesel sample was diluted in n-pentane and 1 µl of this was injected using

an auto-sampler, which was purged before each batch of analysis, and the syringe was

washed thoroughly with the solvent and the sample mixture.

Table 5.37 GCMS Instrument Condition for Analysis of Biodiesel Samples

Column: BP 20 (SGE)







Carrier: Nitrogen at 0.9 ml/min


Temperature: 250°C


Detector: Mass Spectrometer Detector 1.5KV

Mass range 41 m/z – 450m/z



140

5.3.3.2 Results

Table 5.38 Mass Spectral Data of Fatty Acid Esters Analysed.

Samples M + Mass Spectral data

(m/z)

Esters

214 = [C13H26O2]+ Methyl laurate (C 12)

242 = [C15H30O2]+ Methyl tetradecanoate (C 14)

270 = [C17H34O2]+ Methyl hexadecanoate (C 16)

298 = [C19H38O2]+ Methyl octadecanoate (C 18)

Coconut oil methyl

ester

326 = [C21H42O2]+ Methyl Eicosanoate (C 20)

354 = [C23H46O2]+ Methyl docsanoate (C 22)

228= [C14H28O2]+ Ethyl laurate (C 12)

256 = [C16H32O2]+ Ethyl tetradecanoate (C 14)

284 = [C18H36O2]+ Ethyl hexadecanoate (C16)

312 = [C20H40O2]+ Ethyl octdecanoate (C 18)

340 = [C22H44O2]+ Ethyl eicosanoate(C 20)

Coconut oil ethyl

ester

368 = [C24H48O2]+ Ethyl docsanoate (C 22)

Waste oil methyl 270 = [C17H34O2]+ Methyl hexadecanoate (C 16)

ester 298 = [C19H38O2]+ Methyl octadecanoate (C 18)

326 = [C21H42O2]+ Methyl Eicosanoate (C 20)

354 = [C23H46O2]+ Methyl docosanoate (C 22)

382 = [C25H50O2]+ Methyl tetracosanoate (C 24)

Waste oil ethyl ester 284 = [C18H36O2]+ Ethyl hexadecanoate (C16)

312 = [C20H40O2]+ Ethyl octdecanoate (C 18)

340 = [C22H44O2]+ Ethyl eicosanoate(C 20)

368 = [C24H48O2]+ Ethyl docsanoate (C 22)

396 = [C26H52O2]+ Ethyl tetracosanoate (C 24)

Branched chain fatty acids are not included.


141

5.4 PHYSICAL ANALYSIS

5.4.1 Viscocity

5.4.1.1 Methodology

Viscosity of biodiesel samples produced using the various lipid raw materials studied

in chapter 3 was obtained. This was measured using a HAAKE model viscotester

VT6/7 L with L1 (spindle No.1 for low viscosity test fluids) at 200 rpm and 60 rpm.

Five readings for each sample were taken and the average was noted.

5.4.1.2 Results

Table 5.39 Viscosity of biodiesel samples investigated

Samples Viscosity (mPas) @ 27.5 ºC

Coconut oil methyl ester @ 200 rpm 8-9

Coconut oil ethyl esters @ 60 rpm 80-81

Waste oil methyl esters @ 200 rpm 12-14

Waste oil ethyl esters @ 60 rpm 85-87

Relatively the ethyl esters are more viscous than methyl esters as seen. However, the

waste oil esters are relatively more viscous than coconut oil esters. There are higher

percentage composition of longer chain fatty acids in waste oil (C20 and higher)

which are more viscous than short chain fatty acids (C8 and higher) in coconut oil.


142

5.5 IN SUMMARY

Comparison of Analytical Methods

The chromatography analytical techniques employed to determine the quality of

biodiesel includes Gas Chromatography (GC) and Gel Permeation Chromatography

(GPC). Using these techniques the contaminats and ester content can be successfully

determined using respective standard calibration. The suitability of these analytical

techniques to be incorporated as a quality control measure in our region are

determined by looking at the following factors.

Gas Chromatography

Quantification of glycerides (contaminants) and esters are done separately with

different sample preparation and instrumentation methods. Each analysis also used

different columns.


143

Table 5.40 Advantages and Disadvantages of Analysing Biodiesel using GC

Sample

Preparation

Glyceride analysis

Tedious in glyceride quantification.

Requires 45 min of sample derivatisation before dilution.

Derivatising agent is very sensitive to humidity, thus proper storage

procedures need to be followed to prevent degradation of agent.

Derivatised samples are only stable for 2-3 hours.

Ester analysis

Simple dilution of sample.

In both analysis the internal standard regent is pyridine (enhances

stability of standard) and the dilution regent is heptane.

Analysis Glyceride analysis time was 33 minutes and ester run time was 25

minutes.

Data Analysis For both analysis:

Every single component in the sample is quantified.

Identification of the different peak is required in order to group them as

esters or contaminants, then only the total percentage of each in the

sample can be denoted.

Gel Permeation Chromatography

Quantification of each lipid or ester component in the biodiesel sample is impossible

with GPC103. However it is useful in characterising the biodiesel components. This is

greatly an efficient and acceptable method as the standardisation of biodiesel requires

quantification of characterised component rather than the quantification of a specific

component in the biodiesel fuel. For example, according to the Australian Fuel

Quality Standard for biodiesel the specification requires total ester content but not a

specific ester composition, which can be ethyl palmitate, methyl stearate, etc.

Similarly, quantification of total and free glycerol content is required, not mono

palmitic acid, di stearic acid, etc.


144

The importance of quantifying specific components should not be overlooked. Each

component has its own properties and influences the fuel properties of biodiesel when

present is large quantities.

Quantification of glycerides and esters were of homogenous nature. Both parameters

were determined in a single run with the same sample preparation and instrumentation

conditions. This method of analysis can also be used during transesterication reaction

process after diluting and neutralising the samples. Water and alcohol as contaminant

can be analysed together with acylglycerides.

Table 5.41 Advantages and Disadvantages of Analysing Biodiesel using GPC

Sample

Preparation

In both analyses, simple dilution of sample with Tetrahydrofuran was

carried out. No other regents were required.

Analysis Analysis time was 22 minutes.

Data Analysis Glyceride constituents appeared as an overlap of peak that was

quantified as contaminant. The well separated peaks of esters

appeared at a later retention time from which the ester content was

deduced. It required less time to interpret data.

Chapter 6 Conclusion

145

6 CHAPTER 6 CONCLUSION AND

RECOMMENDATION

Raw material analysis

The four lipid sources were analysed for free fatty acid content, iodine value (degree

of saturation), phosphorus and moisture content.

Lipid Source Iodine Value Free Fatty Acid Phosphoru s

content

Moisture

Content

Canola 111.02-132.92 < 1% < 0.03% < 1%

Soybean 116.70-134.47 < 1% < 0.03% < 1%

Waste 40.90-70.03 > 1% Below detection < 1%

Coconut 6.08-9.26 > 1% Below detection < 1%

Coconut oil and waste oil were identified to be the most suitable lipid source for

biodiesle production in Fiji. They are both :

available locally in abundance and accessible,

affordable ,

in consistent supply.

The high FFA content in coconut and waste oil are easily overcome by pre-treatment

procedures like acid pre-treatment process or excess base transesterification process

as investigated in this project. Moisture content of all lipids were less than 1%, thus

considered negligible for transesterification reaction.


146

The other two tests denote the oxidative stability of the corresponding esters produced

from these lipids. Biodiesel from coconut oil should be the most stable followed by

waste, canola and soybean oil.

Pretreatment Methods

The most suitable catalyst for methanolysis and ethanolysis process was 1% sodium

hydroxide and 0.5% potassium hydroxide, respectively.

When comparing molar ratio of alcohol/FFA and catalyst amount in Acid pre-

treatment process, a 20:1 (methanol/FFA) molar ratio with 10% catalyst was the

most suitable mixture for methanolysis. For ethanolysis this was 40:1 (ethanol/FFA)

with 10% catalyst mixture.


Method 1- Acid Pretreatment – One step base transesterification

Methanolysis using method 1 had good separation of layers and no soap formation.

This method had the lowest loss of water solubles during purification with median

loss values of 16.44% for coconut oil biodiesel and 18.61% for waste oil biodiesel.

Coconut oil methyl ester had greater yield with 96.22% (as methyl laurate) percentage

esters and waste oil methyl ester had 28.21% (as methyl oleate). The bound glyceride

content of coconut oil methyl ester sample was 0.61% and waste oil methyl ester

sample had 1.04%.


147

In Ethanolysis there was no separation of acid and lipid layers. This method was

unsuccessful.

It is recommended that for method 1 the reaction time should be increased with lipid

source containing longer chain or branched fatty acids

Method 2A - One step base transesterification

When the reaction was via methanolysis, less than 25% of water solubles were lost

during washing. One step transesterification worked best with coconut oil methyl

esters with percentage yield of 98.39% (as methyl laurate). The bound glyceride

content was found to 4.02% in coconut oil methyl esters.

For ethanolysis less than 56% of water solubles were lost during washing. Separation

of phases became difficult after first few washing. A lot of soap produced. The

percentage of esters was 94.26% (as ethyl laurate), 4.13% less than the methyl esters

prepared using similar method. The bound glyceride content was found to 10.77% in

coconut oil ethyl esters.

It is recommended that method 2A not be used for biodiesel synthesis using lipid

sources with high FFA content. For ethanolysis, a cosolvent such as tetrahydrofuran

can be used to aid separation of the product and by product layers


148

Method 2B - Two step Base Transesterification

Major problem during methanolysis was the high amount of soap production. Less

than 28% of water solubles were lost during washing.Two step base transesterification

had a percentage yield of 94.49% (as methyl laurate).The bound glyceride content

was found to 7.99% in coconut oil methyl esters.

The percentage ester yield obtained via ethanolysis was 93.67% (as ethyl laurate),

0.82%, less than the methyl esters prepare using similar method. There was major loss

of crude biodiesel during washing due to phase separation problems. Less than 67%

of water solubles were lost during washing. The bound glyceride content was found to

10.71% in coconut oil ethyl esters.

Method 2B is also not recommended for lipid sources with high FFA content. For

better ester conversion rates the reaction time should be increased.

Method 3 - Base Neutralisation – One Step base transesterfication.

Coconut oil ethyl ester synthesised using ethanolysis had a greater yield relative to

coconut esters synthesised using other methods (2A and 2B). the yield for coconut oil

ethyl esters was 61.56% (as ethyl laurate) and 28.46% (as ethyl oleate) for . waste oil

ethyl esters. A lot of soap was produced during washing with less than 75% water

solubles lost. The bound glyceride content of coconut oil methyl ester sample was

5.31% and waste oil methyl ester sample had 13.17% bound glyceride content.


149

In this synthetic methodology it is recommended to use saline water washing before

normal water washing for purification process. This synthetic method can be used to

produce quality biodiesel from lipid sources with high FFA value.

Generally, one step base transesterification reaction (method 2A) is more efficient

than two step base (method 2B) transesterification reaction for both cases: Ethanolysis

and methanolysis.

Purification

Fine nozzle dispersion of water was found to be the most effective method of washing.

Salnine water is more effective in removing soap than using only distilled water.

Saline washing does not affect the ester content of biodiesel. It must be noted that the

salinity must be removed by washing with plain water before using biodiesel as fuel.

Analysis and Quantification

The ethyl esters of coconut oil and waste oil were more viscous than its methyl esters.

GPC is a better analytical technique to monitor the progress of biodiesel reaction as it

indicated the contaminants as a group of peak which can easily be quantified. The

general standards for biodiesel requires the total amount of contaminants thus this is

sufficient.

GC techniques complement GPC as it aids in providing extra quality control

information like the exact concentration/percentage of a particular fatty acid ester in

the sample. This information is vital in terms of influence on the physical properties

of biodiesel. Having a higher concentration of a branched or longer chain fatty acid


150

ester increases the vicosity, ignition, cloud and pour point properties of the biodiesel.

See 5.1 Introduction.

Waste oil esters indicate a higher percentage in GPC compared to GC results though

the percentage of esters is represented as Methyl or ethyl oleate. This clearly indicated

the need to identify all of the ester peak in GC analysis to determine the total ester

content. In this respect GPC analysis in more preferred.

Appendix

151

REFERENCE

1. Report of the General Secratery “Sustainable Production, Distribution in Use of

Energy: trends in National Implementation”, Commission of Sustainable

Development, Economic and Social Council, United Nations. 16-27 April, 2001.

2. Pacific Islands Forum Secretariat, “Pacific Fuel Price Monitor-Fuel Prices for

January-April 2006”, Edition 14, September, 2006. Also available on the website:

http://www.forumsec.org/_resources/article/files/PFPM%20Ed%20141.pdf

3. Cloin. J, Woodruff. A and Furstenwerth. D,“Liquid Biofuel in Pacific Island

Countries – SOPAC Micellaneus Report 628.”, 2007.

4. National Biodeisel Board,“Specifications of Biodiesel (B100) ASTM D6751-07a”

March 2007. also available on he website:

http://www.biodiesel.org/pdf_files/fuelfactsheets/BDSpec.PDF

5. Tyson. K.S. “Biodiesel Handling and use Guideline” National Renewable Energy

Laboratory. US Department of Energy. September, 2001.

6. Abdul Monyem, Jon H. Van Gerpen, The effect of biodiesel oxidation on engine

performance and emissions, Biomass and Bioenergy Vol. 20, Iss. 4, April 2001,

pg 317-325.

7. Anastopoulos. G, Lois. E, Karonis. D, Kalligeros. S and Zannikos. F, "Impact of

Oxygen and Nitrogen Compounds on the Lubrication Properties of Low Sulphur

Diesel Fuel",2005, Energy, Vol. 30, no. 2-4. pp. 415-426.

8. Knothe. G, Dunn R. O and Bagby M. O, “Bio-diesel: The Use of Vegetable Oils

and Their Derivatives as Alternative Diesel Fuels”,(online) National Center for

Agricultural Utilization Research, Agricultural Research Service, U.S.

Department of Agriculture, Available from http://www.bio-

Appendix

152

diesel.org/resources/reportsdatabase/reports/gen/19961201_gen-162.pdf (8

February, 2005).

9. Bünger. J, Müller. M. M, Krahl. J, Baum. K, Hallier. E and Schulz. T. G,

“Mutagenicity of Diesel Exhaust Particles of Two Fossil and Two Plant Oil Fuel”

Mutagenesis. Vol 15. No. 5. pp 391 – 397 (2000).

10. Wedel. R. V. “ A Techinical Handbook for Marine Biodiesel in Recreational

Boats” 2nd edition, 1999, CytoCulture International, Inc. Also Available on the net:

http://www.cytoculture.com/Biodiesel%20Handbook.htm#BIODIESEL:%20Fuel

%20Additive%20made%20from%20Vegetable%20Oil

11. Krishna. C. R. “Biodiesel Blends in Space Heating Equipment” 2004, National

Renewable Energy Laboratory. US Department of Energy

12. Wang. W.G, Lyons. D.W, Clark. N. N and Gautam. M, “Emmission From Nine

Heavy Trucks Fueled by Diesel And Biodiesel Blend Without Engine

Modification”, 2000, Environmental Science and Technology, Vol 34, No. 6., pp

933-939.

13. Srivastava. A and Prasad. R, “Triglyceride Based diesel Fuel”, 2000, Renewable

and Sustainable Energy Reviews. Vol 4. pp 111-133.

14. Guru. M, Karakaya. U, Altiparmak. D and Aichilar. A, “Improvement of Diesel

Fuel Properties Using Additives”, Energy Conservation and Management. Vol. 43,

pp1021-1025, (2002).

15. Santana. R. C, Do. P. T, Alvarez. W. E, Taylor. J. D, Sughrue. E. L and Resasco.

D. E. “Evaluation of Different Reaction Strategies for the Improvement of Cetane

Number in Diesel Fuels” Fuel, Vol 85 pp. 643-656 (2006).

16. Coutinho. J. A. P, Mirante. F, Ribeiro. J. C, Sansot. J. M and Daridon. J. L,

“Cloud and Pour Points in Fuel Blends”, Fuel, Vol. 81, pp. 963-967 (2000).

Appendix

153

17. National Biodiesel Board, Press Release, “Ground Breaking Biodesel Tax

Incentives Passes” 11th October, 2004. Also available on the website:

http://www.biodiesel.org/resources/pressreleases/gen/20041011_fsc_passes_senat

e.pdf

18. Kemp. D, Minister for Environment and Heritage, “ Fuel Standard (Biodiesel)

Determination”, 2003, Section 21, Fuel Quality Act 2000.

19. “Challenges and Opportunities to a Viable Biofuel Sector”, 2005, proceedings of

Subregional Workshop of Biofuel, Vanuatu, 1st-5th August. Also available on

http://www.sopac.org/Biofuel+CD+vanuatu.

20. Siwatibau. S, Singh. J and Singh R, “A Note on the Potential Use of Esterification

Coconut Oil as a Lighting Fuel”, Department of Energy, June, (1987).

21. Solly. R. K, “Ethyl Esters of Coconut Oil as Petroleum Fuel Substitute for

Domestic Lamps and Stoves”, National Conference on fuel from Crop, Melbourne,

Proceeding. 1, (1981).

22. Solly. R. D, ““Coconut Oil and Coconut Oil-Ethanol Derivatives as Fuel For

Diesel Engines”, Fiji Agricultural Journal, 42, (1980).

23. Solly. R. K, “Development of Wear Metal in Lubricating Oil of Diesel Engine

Operating on Coconut Oil Fuel”, Presented at the National Conference on fuel

from Crop, Melbourne, (1981).

24. Mario. R, Veikoso. E and Wodruff. A, “An Evaluation of the Biofuel Project in

Taveuni and Vanua Balavu, Fiji Islands”, SOPAC Technical Report 392. February,

2006.

25. Sato. H, Sone. H, Sagai. M, Suzuki. K. T and Aoki. Y, “Increase in Mutangenic

Frequency in Lung of Big Blue Rat by Exposure to Diesel”, Carcenogenesis, Vol

21. No.4. pp. 653-661, 2000.

Appendix

154

26. Burstyn I, Kromhout H, Partanen T, Svane O, Langard S, Ahrens W, Kauppinen T,

Stucker I, Shaham J, Heederik D, Ferro G, Heikkila P, Hooiveld M, Johansen C,

Randem B G and Boffetta P, Nov 2005, “Polycyclic Aromatic Hydrocarbons and

Fatal Ischemic Heart Disease”. Epidemiology. Vol. 16, Iss 6, pp. 744-750.

27. Huang. W, Smith. T. J, Ngo. L, Wang. T, Chan. H, Wu. F, Herrick. R, Christiani.

D. C and Ding. H, “Characterization and Biological Monitoring of Polycyclic

Aromatic Hydrocarbon in Exposes to Diesel Exhaust”, Environmental Science

and Technology, Vol 41, pp 2711-2716, 2007.

28. Wuebbles. D. J and Jain. A. K, “Concerns about Climate Change and the Role of

Fossil Fuel Use”, Fuel Processing Technology, Vol. 71, pp 99-119, 2001.

29. D. McGuire, (CEO American Corn Growers Foundation), Crop Choice, 2004.

30. Hill. J, Nelson. D. T, Polasky. S and Tiffany. D, “Environmental, Economic and

Energetic Cost and Benefits of Biodiesel and Ethanol Biofuels”, Proceedings of

the National Academy of Science of the United States of America. Vol 103. No.

30. pp 11206-11210, July, 2006.

31. Jacobson. M. Z, “Effect of Ethanol (E85) Versus Gasoline Vehicles on Cancer

and Mortality in the United States”, Environmental and Science and Technology,

Vol. 41, pp. 4150-4157, 2007.

32. Sharp. C. A, “Characterisation of Biodiesel Exhaust Emissions for EPA 211 (b)”,

Southwest Reaerch Institute, San Antonio, Texas. 1998.

33. Zhang. X, Peterson. C. L, Reece. D, Moller. G and Haws. R, “Biodegradability of

Biodiesel in the Aquatic Environment” Transactions of the American Society of

Agricultural Engineers, 41, pp. 1423-1430, 1998.

Appendix

155

34. Conneman. J and Fischer. J, “Biodiesel in Europe. Bioidiesel Processing

Technologies”, Paper presented at International Liquid Biodiesel Congress Brazil,

1998, July 19-22nd.

35. Canakci. M and Gerpen. J. V, “A Pilot Plant to Produce Biodeisel From High Free

Fatty Acid Feedstocks”, 2003, Transaction of ASAE, Vol 46 (4), pp. 945-954.

36. Burton G, Ingold K U, “Vitamin E:Application on the Principle of Physical

Organic Chemistry to the Exploration of Its Structure and Function”,1986, Acc.

Chem. Res. Vol. 19. pp 194-201.

37. Suppes. G. J, Dasari. M. A, Doskocil. E.J, Mankidy. P. J and Goff. M. J,

“Transesterification of Soybean Oil With Zeolite and Metal Catalysts”, Applied

Catalysis A General, 2004, Applied Catalysis A: General. Vol. 257, pp. 213–223.

38. Goodrum. J. W, “Volatility and Boiling Point of Biodiesel From Vegetable Oils

and Tallow”, 2002, Biomass and Bioenergy, Vol 22, pp. 205-211.

39. Warabi. Y, Kusdiana. D and Saka. S, “Reactivity of triglycerides and fatty acids

of rapeseed oil in supercritical alcohols”, 2004, Bioresource Technology, Vol. 91,

pp.283-287.

40. Altin. R, Cetinkaya. S, Yucesu. H. S, “The Potential of Using Vegetable Oil Fuels

As Fuel for Diesel Engines”, 2001, Energy Conversion and Management, Vol 42,

pp. 529- 538.

41. Abigor. R.D, Uadia. P. O, Foglia. T. A, Haas. M. J, Jones. K. C, Okpefa, J, U,

Obibuzor. J. U and Bafor. M. E, “Lipase-catalysed production of biodiesel fuel

from some Nigerian lauric oils”, 2000, Biochemical Society Transactions, Vol 28,

part 6, pp. 978-981.

42. Darnoko. D and Cheryan. M, “Kinetics of Palm Oil Transesterification

Appendix

156

in a Batch Reactor”, 2000, Journal of American Oil Chemist Society, Vol. 77, pp.

1263-1267.

43. Leung. D. Y. C and Guo. Y, “Transesterification of Neat and Used Frying Oil:

Optimization For Biodiesel Production”, 2006, Fuel Processing Technology, Vol.

87, pp. 883–890.

44. Sanchez. F and Vasudevan. P. T, “Enzyme Catalyzed Production of Biodiesel

From Olive Oil”, 2006, Applied Biochemistry and Biotechnology, Vol. 135, No. 1,

pp 1-14.

45. Berrios. M, Siles. J, Martin. M. A and Martin. A, “A Kinetic Study Of the

Esterification of Free Fatty Acids (FFA) in Sunflower Oil”, 2007, Fuel,

doi:10.1016/j.fuel.2007.02.002.

46. Antolin. G, Tinaut. F. V, Briceno. Y, Castano. V, Perez. C. P and Ramirez. A. I,

“Optimisation of Biodiesel Production By Sunflower Oil Transesterification”,

2002, Bioresource Technology, Vol. 83, pp. 111–114.

47. Usta. N, Ozturk. E, Can. O, Conkur. E. S, Nas. S, Con. A.H, Can. A. C and Topcu.

M, “Combustion of Biodiesel Fuel Produced From Hazelnut Soapstock/waste

Sunflower Oil Mixture in a Diesel Engine”, 2005, Energy Conversion and

Management, Vol. 46, pp. 741–755.

48. Imahara. H, Minami. E, Hari. S and Saka. S, “Thermal Stability of Biodiesel in

Supercritical Methanol”, 2007, Fuel, doi:10.1016/j.fuel.2007.04.003.

49. Conceica. M. M, Candeia. R. A, Silva. F. C, Bezerra. A. F, Jr Frenandes. V. J and

Souza. A. G, “Thermoanalytical Characterization of Castor Oil Biodiesel”, 2007,

Renewable and Sustainable Energy Reviews, Vol. 11, pp. 964–975.

50. Joshi. R. M and Pegg. M. J, “Flow Properties of Biodiesel Fuel Blends at Low

Temperatures”2007, Fuel, Vol. 86, pp. 143–151.

Appendix

157

51. Zullaikah. S, Lai. C. C, Vali. S. R and Ju. Y. H, “A Two-Step Acid-Catalyzed

Process for the Production of Biodiesel From Rice Bran Oil”,2005, Bioresource

Technology, Vol. 96, pp. 1889–1896.

52. Zhang. H. Y, Hanna. M. A, Ali. Y and Nan. L, “Yellow Nut Sedge (Cyperus

esculentus L.) Tuber Oil as a Fuel”, 1996, Industrial Crops and Products, Vol. 5,

pp. 177-181.

53. Frolich. A and Rice. B, “Evaluation of Camelina sativa Oil As A Feedstock For

Biodiesel Production”, 2005, Industrial Crops and Products, Vol. 21, pp. 25–31.

54. Reyes. J. F and Sepulveda. M. A, “PM-10 Emissions and Power of a Diesel

Engine Fueled With Crude and Refined Biodiesel From Salmon Oil”, 2006, Fuel,

Vol. 85, pp. 1714–1719

55. Dmytryshyn. S. L, Dalai. A. K, Chaudhari. S. T, Mishra. H. K and Reaney. M. J,

“Synthesis and Characterization of Vegetable Oil Derived Esters: Evaluation For

Their Diesel Additive Properties”, 2004, Bioresource Technology, Vol. 92, pp.

55–64.

56. Azam. M. M, Waris. A and Nahar. N. M, “Prospects and Potential of Fatty Acid

Methyl Esters of Some Non-Traditional Seed Oils For Use As Biodiesel In India”,

2005, Biomass and Bioenergy, Vol. 29, pp. 293–302.

57. Tiwari. A. K, Kumar. A and Raheman. H, “Biodiesel Production From Jatropha

Oil (Jatropha curcas) With High Free Fatty Acids: An Optimized Process”, 2007,

Biomass and Bioenergy, doi:10.1016/j.biombioe.2007.03.003

58. Veljkovic. V. B, Lakicevic. S.H, Stamenkovic. O. S, Todorovic. Z.B and Lazic M.

L, “Biodiesel Production From Tobacco (Nicotiana tabacum L.) Seed Oil With a

High Content of Free Fatty Acids”, 2006, Fuel, Vol. 85, pp. 2671–2675.

Appendix

158

59. Ghadge. S. V and Raheman. H, “Process Optimization For Biodiesel Production

From Mahua (Madhuca indica) Oil Using Response Surface Methodology”, 2006,

Bioresource Technology, Vol. 97, pp. 379–384.

60. Raheman. H and Phadatare. A. G, “Diesel Engine Emissions And Performance

From Blends of Karanja Methyl Ester and Diesel”, 2004, Biomass and Bioenergy,

Vol. 27, pp. 393 – 397.

61. Ramadhas. A. S, Jayaraj. S and Muraleedharan. C, “Biodiesel Production From

High FFA Rubber Seed Oil”, 2005, Fuel, Vol. 84, pp. 335–340.

62. Zhang. Y, Dube. M. A, McLean. D. D and Kates. M, “Biodiesel Production From

Waste Cooking Oil: 2. Economic Assessment And Sensitivity Analysis”, 2003,


63. Seiro. M. D, Tesser. R, Dimiccoli. M, Cammarota. F, Nastasi. M and Santacesaria.

E, “Synthesis of Biodiesel Via Homogeneous Lewis Acid Catalyst”,2005, Journal

of Molecular Catalysis A: Chemical, Vol. 239, pp. 111–115.

64. Marchetti. J. M, Migual. V. U and Errazu. A. F, “Heterogeneous Esterification Of

Oil With High Amount Of Free Fatty Acids, 2007, Fuel, Vol. 86, pp. 906–910.

65. Nawar. W. W, “Chemical Changes in Llipid Produced by Thermal Processing”,

1984, Journal of Chemical Education, Vol. 61, No. 4, pp 299-302.

66. Zhang. Y, Dube. M. A. McLean. D. D and Kates. M, “Biodiesel Production From

Waste Cooking Oil: 1. Process Design And Technological Assessment”, 2003,


67. Supple. B, Hildige. R. H, Gomez. E. G and Leahy. J. J, “The Effect of Steam

Treating Waste Cooking Oil on the Yield of Methyl Ester”, 2002, Journal of

American Oil Chemist Society, Vol. 79, pp. 175-178.

Appendix

159

68. Nebel. B. A and Mittelbach. M, “Biodiesel From Extracted Fat Out of Meat and

Bone Meal”, 2006, European Journal of Lipid Science and Technology, Vol. 108,

pp. 398-403.

69. Haas. M. J, “Improving the economics of biodiesel production through the use of

low value lipids as feedstocks: vegetable oil soapstock” 2005, Fuel Processing

Technology, Vol. 86, pp. 1087– 1096.

70. King. J. W, Taylor. S. L, Synder. J. M and Holliday. R. L, “Total Fatty Acid

Analysis of Vegetable Oil Soapstocks by Supercritical Fluid Extraction/Reaction”,

71. Dufreche. S, Hernandez. R, French. T, Sparks. D, Zappi. M and Alley. E,

“Extraction of Lipids from Municipal Wastewater Plant Microorganisms for

Production of Biodiesel”, 2007, Journal of American Oil Chemist Society, Vol. 84,

pp. 181-187.

72. Sheehan. J, Dunahay. T, Benemann. J and Roessler. P, “A Look Back at the U.S.

Department of Energy’s Aquatic Species Program—Biodiesel from Algae”, 1998,

National Renewable Energy Laboratory, NREL/TP-580-24190.

73. Xu. H, Miao. X and Wu. Q, “High quality biodiesel production from a microalga

Chlorella protothecoides by heterotrophic growth in fermenters”, 2006, Journal of

Biotechnology, Vol. 126, pp. 499-507.

74. Issariyakul. T, Kulkarni. M. G, Dalai. A K. and Bakhshi. N. N, “Production of

Biodiesel From Waste Fryer Grease Using Mixed Methanol and Ethanol System”,

2007, Fuel Processing Technology, Vol 88, pp. 429-436.

75. Abigor. R. D, Uadia. P. O, Foglia. T. A, Haas. M. J, Jones K. C, Okpefa. E,

Obibuzor. J. U and Bafor M. E, “Lipase-Catalysed Production of Biodiesel Fuel

From Some Nigerian Lauric Oils”, 2000, Biochemical Society Transactions, Vol.

28, Part 6, pp. 979-981.

Appendix

160

76. Demirbas. A, “Biodiesel Production Via SCF Method and Biodiesel Fuel

Characteristics” 2006, Energy Conversion and Management, Vol. 47, pp. 2271-

2282.

77. Mittelbach. M and Remschmidt. C, “Biodiesel-The Comprehensive Handbook”,

2005, Am Blumenhang 27, A-8010 Graz, Austria. Pp.48-60.

78. Iso. M, Chen. B, Eguchi. M, Kudo. T and Shrestha. S, “Production of biodiesel

fuel from triglycerides and alcohol using immobilized lipase”, 2001, Journal of

Molecular Catalysis B: Enzymatic, Vol. 16, pp53-58.

79. Official and Tentative Methods of the American Oil Chemist’s Society, Third

Edition, Sampling and Analysis of Commercial Fats and Oils, Method Number Ca

5a-40, Free Fatty Acids.


Edition, Sampling and Analysis of Commercial Fats and Oils, Method Number Cd

1-25, Iodine Value (Wijs Method).

81. Pocklington. W. D. “Determination of Iodine Value of Oils and Fats. Results of a

Collaborative Study”, 1990, Pure and Applied Chemistry, Vol.62, No.12,

pp.2339-2343.



12-55, Phosphorous.



2b-38, Moisture and Volatile Matter, Hot Plate Method.

Appendix

161

84. Freedman. B, Pryde. E. H and Mounts. T. L, “Variables Affecting the Yeild of

Fatty Ester From Transesterified Vegetable Oil”, 1984, Journal of American Oil

Chemist Society, Vol. 61, no. 10, pp. 1638-1643.

85. Szybist. J. P, Boehman. A. L, Taylor. J. D and McCormick. R. L, “Evaluation of

Formulation of Startergies of Biodiesel to Eliminate the NOx Effect”, 2005, Fuel

Processing Technology, vol 86, pp 1109-1126.

86. Noureddini. H and Zhu. D, “Kinetics of Transesterificatio of Soybean Oil”,1997,

Journal of the American Oil Chemist Society, Vol.74. No. 11 pg. 1457-1463.

87. Schuchardt. U, Sercheli. R and Vargas. R. M, “Transesterification of Vegetable

Oils: A Review”, 1998,Journal of the Brazillian Chemical Society, Vol. 9, No. 1,

pg 199-210.

88. Canakci. M and Gerpen. J. V, “Biodiesel Production from Oils and Fats with High

Free Fatty Acids”, 2001, Transaction of the ASAE, Vol. 44 (6), pp. 1429-1436.

89. Canakci. M and Gerpen. J. V, “Biodiesel Production Via Acid Catalyst”, 1999,

Transaction of ASAE, Vol 42 (5), pp.1203-1210.

90. Berrios. M, Siles. J, Martin. M. A and Martin A, “A kinetic study of the

esterification of free fatty acids (FFA) in sunflower oil”, 2007, Fuel , Vol 57 (3),

pp. 223-228.

91. Clements. L. D “Blending Rules For Formulating Biodiesel Fuel”, 1996,

Proceedings of the 3rd Liquid Fuels Conference organised by ASAE. pg 44,

Nashville, TN, USA. 15-17 September.

92. Holcapek. M, Jandera. P, Fischer. J and Prokes. B, “Analytical Monitoring of the

production of Biodiesel By High Performance Liquid Chromatography With

Variuos Detection Methods”, 1999. Journal of Chromatography A, Vol. 858, pg

13-31.

Appendix

162

93. Neto. P .R. C, Caro. M. S. B, Mazzuco. L, M and Nascimento. M. D,

“Quantification of Soybean Ethanolysis with 1H NMR”, 2004, Journal of the

American Oil Chemist’s Society”, Vol. 81, pg 1111-1114.

94. Bondioli. P and Bella. L. D, “An Alternative Spectrometeric Method for the

Determination of Free Glycerol in Biodiesel”, 2005, European Journal of Lipid

Science and Technology, Vol. 107, pg 153-157.

95. Knothe. G, “Rapid Monitoring of Transesterification and Assessing Biodiesel

Fuel Quality by Near Infrared Spectroscopy Using a Fiber-Optic Probe”, 1999,

Journal of the American Oil Chemist’s Society”, Vol. 76, No. 7, pg 795-800.

96. Fillieres, R. Benjelloun-Mlayah. B, M. Delmas, “Ethanolysis of Rapeseed Oil:

Quantitation of Ethyl Esters, Mono-, Diand Triglycerides and Glycerol by High-

Performance Size-Exclusion Chromatography,” 1995, Journal of American Oil

Chemist Society, Vol. 72, No.4, pg. 427-432.

97. Pinto A.C, Guarieiro L. L. N, Rezende M. J. C, Ribeiro N. M, Torres. E. A, Lopes

W. A, Pereira. P. A. P, de Andrade J. B. “Biodiesel : An Overview”, 2005, Journal

of Brazilian Chemical Society. Vol. 16, No. 6B. pg 1313-1330.

98. Schober. S, Seidl. I and Mittelbach. M, “Ester Content Evaluation in Biodiesel

from Animal Fats and lauric Oils”, 2006, European Journal of Lipid Science and

Technology, Vol 108, pp. 309-314.

99. Bondioli. P, Lanzani. A, Fedeli. E, Sala. M and Veronese. S, “Vegetable oil

derivative as Diesel fuel substitutes: Analytical Aspects.

Note 4: Determination of biodiesel and diesel fuel in mixture”, 1994. Riv. Ital.

Sostanze Grasse, Vol. 71(6), pp.287-289.

100. Bondioli. P, Marani. C, Lanzani. A, Fedeli. E and Veronese. S, “ Vegetable oil

derivative as Diesel fuel substitutes: Analytical Aspects.

Appendix

163

Note 2: Determination of Free Glycerol”. Riv. Ital. Sostanze Grasse 69(1):

7-9. 1992a.

101. Darnoko. D, Cheryan. M and perkin E. G, “Analysis of Vegetable Oil

Transesterification Products by Gel Permeation Chromatography”, 2000, Journal

of Liquid Chromatography and Related Technologies, Vol. 23 (15), pp. 2327-

2335.

102. Plank. C and Lorbeer. E, “Simultaneous Determination of Glycerol, Mono-,

Di- and Triglycerides in Vegetable Oil Methyl Esters By Capillary Gas

Chromatography”, 1995, Journal of Chromatography A, Vol. 697, Issue 1-2, pp.

461-468.

103. Arzamendi G, Argui˜narena E, Campo I, Gand´ıa L.M, “Monitoring of

biodiesel production: Simultaneous analysis of the transesterification products

using size-exclusion chromatography”, 2006, Chemical Engineering Journal. Vol.

122, pp. 31–40.

Appendix

164

APPENDIX

FREE FATTY ACID

Table A1. Free Fatty Acid and Acid Values of Soybean oil

Titer Volume

(ml)

Weight of Sample (g)

Normality of NaOH Solution

(N)

Free Fatty Acid (FFA)

% Acid Value

C001soy A 1.60 28.2088 0.1000 0.16 0.32

Oleic acid B 1.50 28.2003 0.1000 0.15 0.30

C 1.60 28.2102 0.1000 0.16 0.32

C021soy A 2.20 28.0434 0.0968 0.21 0.43

Oleic acid B 2.20 28.0451 0.0968 0.21 0.43

C 2.20 28.0710 0.0968 0.21 0.43

C031soy A 1.70 28.0337 0.0968 0.17 0.33

Oleic acid B 1.70 28.0020 0.0968 0.17 0.33

C 1.60 28.0282 0.0968 0.16 0.31

C002soy A 1.40 28.0267 0.0968 0.14 0.27

Oleic acid B 1.30 28.0221 0.0968 0.13 0.25

C 1.40 28.0050 0.0968 0.14 0.27

C022soy A 1.20 28.0895 0.0968 0.12 0.23

Oleic acid B 1.30 28.0847 0.0968 0.13 0.25

C 1.30 28.0661 0.0968 0.13 0.25

C032soy A 1.40 28.0001 0.0968 0.14 0.27

Oleic acid B 1.40 28.0020 0.0968 0.14 0.27

C 1.30 28.0282 0.0968 0.13 0.25

Where:

C001soy – brand 1, soybean oil bottle 1






Appendix

165

Table A2. Free Fatty Acid and Acid Values of Canola oil

Titer

Volume (ml)



(N)


% Acid Value

C001can A 1.90 28.2234 0.1000 0.19 0.38 Oleic acid B 1..90 28.2162 0.1000 0.19 0.38

C 1.80 28.2162 0.1000 0.18 0.36 C021can A 1.70 28.0243 0.0968 0.17 0.33 Oleic acid B 1.60 28.0247 0.0968 0.16 0.31

C 1.70 28.0769 0.0968 0.17 0.33 C031can A 1.70 28.0924 0.0968 0.17 0.33 Oleic acid B 1.70 28.0696 0.0986 0.17 0.34 C 1.70 28.0812 0.0968 0.17 0.33 C002can A 2.20 28.0330 0.0968 0.21 0.43 Oleic acid B 2.30 28.0140 0.0968 0.22 0.45 C 2.20 28.0509 0.0968 0.21 0.43 C022can A 3.10 28.0062 0.0968 0.30 0.60 Oleic acid B 3.10 28.0049 0.0968 0.30 0.60 C 3.20 28.0987 0.0968 0.31 0.62 C032can A 2.20 28.0920 0.0968 0.21 0.43 Oleic acid B 2.20 28.0892 0.0968 0.21 0.43 C 2.20 28.0236 0.0968 0.21 0.43

Where: C001can – brand 1, canola oil bottle 1 C021can – brand 1, canola oil bottle 2 C031can – brand 1, canola oil bottle 3 C002can – brand 2, canola oil bottle 1 C022can – brand 2, canola oil bottle 2 C032can – brand 2, canola oil bottle 3

Appendix

166

Table A3. Free Fatty Acid and Acid Values of Coconut oil

Titer Volume

(ml)



(N)


% Acid Value

C001coco A 5.30 7.0178 0.2393 3.61 10.14 Lauric acid B 5.20 7.0481 0.2393 3.53 9.90

C 5.30 7.0319 0.2393 3.61 10.12


C 5.20 7.0113 0.2393 3.55 9.96


C 5.20 7.0379 0.2393 3.54 9.92


C 4.50 7.0340 0.2447 3.13 8.78


C 6.10 7.0450 0.2470 4.28 12.00


C 6.00 7.0920 0.2447 4.14 11.61

Where:

C001coco – brand 1, coconut oil bottle 1






Appendix

167

Table A4. Free Fatty Acid and Acid Values of Waste Oil

Titer Volume

(ml)



(N)


% Acid Value

W001p A 1.85 7.0786 0.2393 1.60 3.51

Palmitic acid B 1.90 7.0312 0.2393 1.66 3.63

C 1.85 7.0473 0.2393 1.61 3.52

W021p A 6.70 7.0392 0.2393 5.83 12.78

Palmitic acid B 6.80 7.0512 0.2393 5.91 12.95

C 6.80 7.0207 0.2393 5.93 13.00

W031p A 14.70 7.0067 0.2393 12.85 28.16

Palmitic acid B 14.50 7.0263 0.2393 12.64 27.70

C 14.60 7.0282 0.2393 12.73 27.89

W002s A 12.70 7.0619 0.2393 11.02 24.14

Oleic acid B 12.60 7.0435 0.2393 10.96 24.02

C 12.60 7.0326 0.2393 10.98 24.05

W022s A 6.75 7.0492 0.2393 5.87 12.85

Oleic acid B 6.75 7.0635 0.2393 5.85 12.83

C 6.80 7.0481 0.2393 5.91 12.95

W032s A 13.70 7.0341 0.2393 11.93 26.15

Oleic acid B 13.85 7.0154 0.2393 12.09 26.50

C 13.20 7.0523 0.2393 11.47 25.13

W003s A 0.60 7.0133 0.2393 0.52 1.15

Oleic acid B 0.55 7.0529 0.2393 0.48 1.05

C 0.60 7.0288 0.2393 0.52 1.15

W023s A 1.10 7.0751 0.2393 0.95 2.09

Oleic acid B 1.05 7.0608 0.2393 0.91 2.00

C 1.05 7.0495 0.2393 0.91 2.00

W033s A 1.00 7.0378 0.2393 0.87 1.91

Oleic acid B 0.95 7.0314 0.2393 0.83 1.81

C 0.90 7.0472 0.2393 0.78 1.71

Where: W001p – waste oil from source 1, batch 1

W021p – waste oil from source 1, batch 2

W031p – waste oil from source 1, batch 3

W002s – waste oil from source 2, batch 1






Appendix

168

IODINE VALUE

Table A5. Iodine value of Soybean oil

Iodine value calculated ranged from 116.70 - 134.47 (Table 3.10)

Soybean oil

Rep

licat

es A

Titer Volume of Blank

(ml)

B Titer

Volume of Sample

(ml)

A-B (ml)

Weight of

Sample (g)

Normality of

Na2S2O3 Solution

(N)

Iodine Value

Average Iodine Value

C001soy A 49.70 28.90 20.80 0.2120 0.1042 129.7349 B 49.70 29.00 20.70 0.2063 0.1042 132.6785 C 49.70 28.90 20.80 0.2080 0.1042 132.2298

131.55

C021soy A 50.10 28.25 21.85 0.2182 0.1042 132.4116 B 50.10 30.00 20.10 0.2009 0.1042 132.2956 C 50.10 29.14 20.96 0.2135 0.1042 129.8144

131.51

C031soy A 52.05 31.30 20.75 0.2015 0.1029 134.4683 B 52.05 30.65 21.40 0.2091 0.1029 133.6401 C 52.05 30.70 21.35 0.2122 0.1029 131.3801

133.16

C002soy A 51.20 30.60 20.60 0.2094 0.1029 128.4599 B 51.20 30.10 21.10 0.2128 0.1029 129.4756 C 51.20 30.70 20.50 0.2070 0.1029 129.3185

129.08

C022soy A 51.20 30.50 20.70 0.2088 0.1029 129.4544 B 51.20 31.40 19.80 0.2048 0.1029 126.2444 C 51.20 31.80 19.40 0.2060 0.1029 122.9735

126.22

C032soy A 50.85 29.50 21.35 0.2389 0.1029 116.6967 B 50.85 29.20 21.65 0.2357 0.1029 119.9431 C 50.85 28.70 22.15 0.2410 0.1029 120.0145

118.88

Appendix

169

Table A6. Iodine value of Canola Oil

Iodine value calculated ranged from 111.02-132.92 (Table 3.10)

Canola oil

Rep

licat

es

A Titer

Volume of Blank (ml)

B Titer

Volume of

Sample (ml)

A-B (ml)

Weight of

Sample (g)

Normality of

Na2S2O3 Solution

(N)

Iodine Value


C001can A 49.70 27.40 22.30 0.2428 0.1042 121.447

B 49.70 28.20 21.50 0.2342 0.1042 121.389

C 49.70 28.60 21.10 0.2303 0.1042 121.148 121.33

C021can A 50.10 29.30 20.80 0.2372 0.1042 115.952

B 50.10 29.20 20.90 0.2383 0.1042 115.972

C 50.10 28.95 21.15 0.2331 0.1042 119.977 117.30

C031can A 52.05 30.10 21.95 0.2309 0.1029 124.133

B 52.05 28.90 23.15 0.2457 0.1029 123.033

C 52.05 29.30 22.75 0.2445 0.1029 121.501 122.89

C002can A 51.20 30.10 21.10 0.2410 0.1029 114.325

B 51.20 29.95 21.25 0.2473 0.1029 112.205

C 51.20 30.20 21.00 0.2470 0.1029 111.020 112.52

C022can A 51.20 30.50 20.70 0.2305 0.1029 117.267

B 51.20 30.50 20.70 0.2339 0.1029 115.563

C 51.20 30.55 20.65 0.2427 0.1029 111.103 114.64

C032can A 50.85 29.80 21.05 0.2068 0.1029 132.917

B 50.85 29.80 21.05 0.2089 0.1029 131.580

C 50.85 29.50 21.35 0.2161 0.1029 129.009 131.17

Appendix

170

Table A7. Iodine value of Coconut oil

Iodine value calculated ranged from 6.08-9.26 (Table 3.10)

A Titer


B Titer

Volume of Sample

(ml)

A-B (ml)

Weight of

Sample (g)

Normality of

Na2S2O3 Solution

(N)

Iodine Value


C001coco A 49.70 43.55 6.15 1.2209 0.1042 6.6608

B 49.70 43.00 6.70 1.2353 0.1042 7.1719

C 49.70 42.85 6.85 1.2188 0.1042 7.4317 7.09

C021coco A 50.10 42.90 7.20 1.2228 0.1042 7.7859

B 50.10 42.95 7.15 1.2134 0.1042 7.7917

C 50.10 43.25 6.85 1.2254 0.1042 7.3917 7.66

C031coco A 52.05 44.20 7.85 1.2174 0.1029 8.4200

B 52.05 44.30 7.75 1.2240 0.1029 8.2679

C 52.05 45.35 6.70 1.2154 0.1029 7.1951 7.96

C002coco A 51.20 43.10 8.10 1.2243 0.1029 8.6392

B 51.20 43.60 7.60 1.2397 0.1029 8.0052

C 51.20 43.90 7.30 1.2182 0.1029 7.8249 8.16

C022coco A 51.20 45.60 5.60 1.2033 0.1029 6.0770

B 51.20 43.50 7.70 1.2140 0.1029 8.2823

C 51.20 43.55 7.65 1.2152 0.1029 8.2204 7.53

C032coco A 50.85 42.60 8.25 1.2176 0.1029 8.8476

B 50.85 42.25 8.60 1.2128 0.1029 9.2595

C 50.85 42.40 8.45 1.2126 0.1029 9.0995 9.07

Appendix

171

Table A8. Iodine value of Waste oil

Iodine value calculated ranged from 46.69 – 68.95 (Table 3.11)

A Titer


B Titer

Volume of Sample

(ml)

A-B (ml)

Weight of

Sample (g)

Normality of

Na2S2O3 Solution

(N)

Iodine Value


W001p A 51.10 33.50 17.60 0.4465 0.1029 51.4717

B 51.10 32.30 18.80 0.4836 0.1029 50.7631

C 51.10 32.20 18.90 0.4838 0.1029 51.0121 51.08

W021p A 51.10 32.55 18.55 0.4757 0.1018 50.3756 B 51.10 32.30 18.80 0.4850 0.1018 50.0755

C 51.10 33.30 17.80 0.4801 0.1018 47.8958 49.45

W031p A 51.10 33.80 17.30 0.4837 0.1018 46.2040

B 51.10 33.60 17.50 0.4709 0.1018 48.0086

C 51.10 33.50 17.60 0.4770 0.1018 47.6654 47.29

W002s A 51.10 41.15 9.95 0.2090 0.1029 62.1661 B 51.10 40.50 10.60 0.2174 0.1029 63.6683

C 51.10 40.70 10.40 0.2095 0.1029 64.8226 63.55

W022s A 51.10 40.95 10.15 0.2144 0.1018 61.1576

B 51.10 42.70 8.40 0.2097 0.1018 51.7476

C 51.10 41.90 9.20 0.2155 0.1018 55.1506 56.02

W032s A 51.10 41.55 9.55 0.2147 0.1018 57.4620 B 51.10 44.00 7.10 0.2118 0.1018 43.3054

C 51.10 44.70 6.40 0.2103 0.1018 39.3143 46.69

W003s A 51.10 40.50 10.60 0.2041 0.1029 67.8172

B 51.10 40.40 10.70 0.2025 0.1029 68.9979

C 51.10 39.50 11.60 0.2163 0.1029 70.0291 68.95

W023s A 51.10 44.30 6.80 0.2148 0.1018 40.8963 B 51.10 44.35 6.75 0.2031 0.1018 42.9342

C 51.10 41.70 9.40 0.2125 0.1018 57.1450 46.99

W033s A 51.10 41.70 9.40 0.2016 0.1018 60.2347

B 51.10 41.70 9.40 0.2011 0.1018 60.3845

C 51.10 41.20 9.90 0.2101 0.1018 60.8721 60.50

Appendix

172

PHOSPHOROUS CONTENT

Table A9. Phosphorous Content of Soybean oil

Phosphorus content of soybean oil ranged from 0.0003%-0.0277 % (table 3.12)

A Phosporous Content of Sample in

Aliquot (mg)

B Phosphorous

Content of Blank (mg)

A-B (mg)

W Weight of Sample

(g)

Phosphorus % 10(A-B)/WV

Average (%)

C001soy A 0.0830 0.0003 0.0833 3.0307 0.0275 B 0.0830 0.0003 0.0833 3.0287 0.0275

C 0.0830 0.0003 0.0833 3.0470 0.0274

0.03

C021soy A 0.0015 0.0003 0.0018 3.0315 0.0006 B 0.0010 0.0003 0.0013 3.0211 0.0004

C 0.0830 0.0003 0.0833 3.0060 0.0277

0.01

C031soy A 0.0005 0.0003 0.0008 3.0186 0.0003 B 0.0006 0.0003 0.0009 3.0246 0.0003

C 0.0830 0.0003 0.0833 3.0481 0.0273

0.01

C002soy A 0.0008 0.0003 0.0011 3.0258 0.0004 B 0.0042 0.0003 0.0045 3.0010 0.0015

C 0.0830 0.0003 0.0834 3.0124 0.0277

0.01

C022soy A 0.0830 0.0003 0.0834 3.0238 0.0276 B 0.0830 0.0003 0.0834 3.0377 0.0274

C 0.0830 0.0003 0.0834 3.0262 0.0275

0.03

C032soy A 0.0830 0.0003 0.0834 3.0510 0.0273 B 0.0830 0.0003 0.0834 3.0347 0.0275

C 0.0830 0.0003 0.0834 3.0383 0.0274

0.03

Appendix

173

Table A10. Phosphorous Content of Canola Oil

Phosphorus content of canola oil ranged from 0.0001%-0.0276% (table 3.12)

A Phosporous Content of Sample in

Aliquot (mg)

B Phosphorous

Content of Blank (mg)

A-B

W Weight of Sample

(g)

Phosphorus % 10(A-B)/WV

Average (%)

C002can A 0.0014 0.0003 0.0018 3.0570 0.0006 B 0.0015 0.0003 0.0018 3.0980 0.0006

C 0.0010 0.0003 0.0013 3.0718 0.0004

ND

C022can A 0.0001 0.0003 0.0004 3.0408 0.0001 B 0.0014 0.0003 0.0017 3.0971 0.0005

C 0.0013 0.0003 0.0016 3.0479 0.0005

ND

C032can A -0.0002 0.0003 0.0002 3.0211 0.0001 B 0.0001 0.0003 0.0004 3.0210 0.0001

C 0.0001 0.0003 0.0004 3.0150 0.0001

ND

C001can A 0.0830 0.0001 0.0832 3.0156 0.0276 B 0.0830 0.0001 0.0832 3.0303 0.0274 C 0.0830 0.0001 0.0832 3.0180 0.0276

0.03

C021can A 0.0830 0.0001 0.0832 3.0200 0.0275 B 0.0830 0.0001 0.0832 3.0110 0.0276

C 0.0830 0.0001 0.0832 3.0320 0.0274

0.03

C031can A 0.0830 0.0001 0.0832 3.0185 0.0275 B 0.0830 0.0001 0.0832 3.0348 0.0274

C 0.0830 0.0001 0.0832 3.0182 0.0276

0.03

ND – not detectable, percentage of phosphorous is below significant range.

Appendix

174

MOISTURE AND VOLATILE MATTER

Table A11. Moisture Content and Volatile Matter of Soybean oil

Soybean Oil

Initial

weight (A)

Final weight

(B)

Weight loss (C) A-B

(D) Weight of sample (g)

Moisture and Volatile Matter

Content (C/100)/D

A 52.1399 52.1363 0.0036 20.16 0.0179

B 51.7189 51.7081 0.0108 20.16 0.0536

C00

1soy

C 53.2781 53.2676 0.0105 20.0172 0.0525 A 52.5399 52.527 0.0129 20.0091 0.0645

B 51.0513 51.0399 0.0114 20.0266 0.0569

C02

1soy

C 52.8001 52.7895 0.0106 20.0158 0.0530 A 53.2363 53.2251 0.0112 20.0407 0.0559

B 52.8782 52.8664 0.0118 20.1392 0.0586

C03

1soy

C 52.4063 52.3965 0.0098 19.6533 0.0499

A 38.7112 38.6991 0.0121 19.9945 0.0605

B 38.4621 38.4501 0.012 20.1751 0.0595

C00

2soy

C 39.6221 39.6101 0.012 19.9839 0.0600

A 38.6321 38.6205 0.0116 20.001 0.0580 B 39.7397 39.7272 0.0125 20.005 0.0625

C02

2soy

C 41.6468 41.6354 0.0114 19.8313 0.0575

A 39.3884 39.3713 0.0171 19.8296 0.0862 B 39.6743 39.6622 0.0121 20.0177 0.0604

C03

2soy

C 38.7287 38.7152 0.0135 20.0713 0.0673

Appendix

175

Table A12. Moisture Content and Volatile Matter of Canola oil

Canola Oil

Initial

weight (A)

Final weight

(B)

Weight loss (C) A-B



Content (C/100)/D

A 51.7033 51.693 0.0103 20.0109 0.0515 B 52.1775 52.1669 0.0106 19.9974 0.0530

C00

1can

C 52.7434 52.7329 0.0105 20.0059 0.0525

A 52.0226 52.0102 0.0124 20.009 0.0620

B 53.06651 53.0561 0.01041 20.0457 0.0519

C02

1can

C 51.8279 51.8181 0.0098 20.0305 0.0489

A 52.5649 52.5556 0.0093 20.0399 0.0464

B 52.7089 52.6974 0.0115 20.5099 0.0561

C03

1can

C 52.4755 52.4587 0.0168 20.0712 0.0837

A 46.5871 46.5767 0.0104 20.0624 0.0518

B 51.1944 51.18 0.0144 20.0068 0.0720

C00

2can

C 52.5624 52.5528 0.0096 20.0574 0.0479

A 51.3157 51.3061 0.0096 20.0048 0.0480 B 52.1811 52.1704 0.0107 20.0178 0.0535

C02

2can

C 53.0312 53.0204 0.0108 20.0233 0.0539

A 56.3132 56.3025 0.0107 20.0061 0.0535

B 52.1091 52.0981 0.011 20.0166 0.0550

C03

2can

C 46.9241 46.9139 0.0102 20.043 0.0509

Appendix

176

Table A13. Moisture Content and Volatile Matter of Coconut oil

Coconut Oil

Initial

weight (A)

Final weight

(B)

Weight loss (C) A-B



Content (C/100)/D

A 38.3768 38.3226 0.0542 19.8037 0.2737

B 37.3445 37.3201 0.0244 19.9517 0.1223 C00

1coc

o

C 39.8921 39.8351 0.057 20.158 0.2828 A 38.3345 38.2758 0.0587 19.995 0.2936

B 38.623 38.5666 0.0564 20.0017 0.2820 C02

1coc

o

C 38.7602 38.7058 0.0544 20.0871 0.2708

A 38.1878 38.1221 0.0657 20.0809 0.3272

B 38.7479 38.6869 0.061 20.0571 0.3041 C03

1coc

o

C 39.5678 39.515 0.0528 20.0202 0.2637

A 21.4876 21.4682 0.0194 9.9937 0.1941

B 20.3899 20.3605 0.0294 10.0235 0.2933 C00

2coc

o

C 21.9874 21.9589 0.0285 10.0641 0.2832

A 50.2021 50.1209 0.0812 20.5037 0.3960

B 51.0862 51.0066 0.0796 20.0162 0.3977 C02

2coc

o

C 68.4494 68.3661 0.0833 19.8821 0.4190 A 21.6142 21.5874 0.0268 9.9653 0.2689

B 28.7247 28.6998 0.0249 10.073 0.2472 C03

2coc

o

C 31.6382 31.6164 0.0218 10.0149 0.2177

Appendix

177

Table A14. Moisture Content and Volatile Matter of Waste oil

Waste Oil

Initial

weight (A)

Final weight

(B)

Weight loss (C) A-B



Content (C/100)/D

A 38.003 37.9818 0.0212 19.255 0.1101 B 38.0366 38.0195 0.0171 19.3569 0.0883

W00

1p

C 37.9992 37.9708 0.0284 19.295 0.1472

A 38.6443 38.6167 0.0276 19.7718 0.1396

B 38.2741 38.1999 0.0742 19.6048 0.3785

W02

1p

C 39.3456 39.3195 0.0261 19.7571 0.1321

A 70.9569 70.9407 0.0162 20.048 0.0808

B 46.3302 46.2962 0.034 20.0409 0.1697

W03

1p

C 52.235 52.2031 0.0319 19.9561 0.1599

A 37.9908 37.9505 0.0403 20.0256 0.2012

B 38.084 38.0429 0.0411 19.9961 0.2055

W00

2s

C 38.0547 38.0102 0.0445 19.9674 0.2229

A 39.0682 39.0395 0.0287 19.4728 0.1474 B 38.5366 38.5043 0.0323 19.7786 0.1633

W02

2s

C 38.4749 38.4469 0.028 19.7795 0.1416

A 51.5518 51.5059 0.0459 19.9691 0.2299

B 38.0771 38.0422 0.0349 20.0867 0.1737

W03

2s

C 51.915 51.8657 0.0493 19.9403 0.2472

A 38.0671 38.0546 0.0125 19.9725 0.0626

B 37.9598 37.9443 0.0155 19.9366 0.0777

W00

3s

C 37.9953 37.9817 0.0136 19.7988 0.0687

A 38.6315 38.6287 0.0028 19.9357 0.0140

B 39.5839 39.5708 0.0131 19.7973 0.0662

W02

3s

C 38.839 38.8264 0.0126 20.111 0.0627

A 72.0262 71.8519 0.1743 20.0709 0.8684 B 50.0249 49.876 0.1489 19.9803 0.7452

W03

3s

C 52.9749 52.8251 0.1498 20.0925 0.7456

Appendix

178

BIODIESEL SYNTHESIS

Acid pretreatment, one-step basic transesterification (Method 1) – coconut oil methyl esters

– waste oil methyl ester

Table A.15 Pretreatment of Coconut oil - METHANOLYSIS

C001coco C021coco C031coco C002coco C022coco C032co co Coconut Oil Properties . Mass of feedstock (g) 200.39 200.06 200.04 200.39 200.35 200.56 Free Fatty Acids (%) 3.5843 3.5214 3.5155 3.1656 4.2589 4.2637 Mass of FFA in stock (g) 7.1826 7.0449 7.0324 6.3435 8.5327 8.5513 Mr. of Free fatty Acid (g/moles) 200.3 200.3 200.3 200.3 200.3 200.3

Moles of Free fatty Acid (moles) 0.0359 0.0352 0.0351 0.0317 0.0426 0.0427 Methanol Properties Moles of Methanol (moles) 0.7172 0.7034 0.7022 0.6334 0.8520 0.8538 Mr. of Methanol (g/moles) 32 32 32 32 32 32 Mass of Methanol (g) 22.9498 22.5100 22.4700 20.2689 27.2638 27.3231 Density of Methanol (g/ml) 0.791 0.791 0.791 0.791 0.791 0.791

Volume of Methanol (ml) 29.0137 28.4576 28.4071 25.6245 34.4675 34.5425 Acid Properties

Mass of H2SO4 ( 10% of FFA) g 0.7183 0.7045 0.7032 0.6344 0.8533 0.8551 Density of H2SO4 (g/ml) 1.8 1.8 1.8 1.8 1.8 1.8

Volume of H2SO4 (ml) 0.3990 0.3914 0.3907 0.3524 0.4740 0.4751 Condition set for coconut oil methanol pretreatment: 20:1methanol to FFA, 10% sulphuric acid.

Table A.16 FFA of Pretreated Coconut Oil.

Titer Volume

(ml)



(N)


%

Acid Value (mg

KOH/g)

C001coco-1-Oil 6.60 28.2597 0.1095 0.5115 1.4347 C021coco-1-Oil 6.80 28.2553 0.1095 0.5271 1.4784 C031coco-1-Oil 10.05 28.3894 0.1095 0.7753 2.1746 C002coco-1-Oil 11.60 28.2218 0.1095 0.9002 2.5249 C022coco-1-Oil 6.85 28.2666 0.1095 0.5307 1.4887

C032coco-1-Oil 6.35 28.2848 0.1095 0.4917 1.3791 Acid Value = (ml)(N)(56.1*)/(g)

* 56.1 = molecular weight (or equivalent weight) of KOH.

Appendix

179

Table A.17 Transesterification of Pretreated Coconut Oil

Catalyst to neutralise leftover FFA before transesterification

C001coco-

1-oil C021coco-

1-oil C031coco-

1-oil C002coco-

1-oil C022coco-

1-oil C032coco-

1-oil Mass of pretreated oil (g) 100.7400 100.2700 100.9600 100.5800 100.4900 100.3900 Acid Value (mg KOH/g) 1.4347 1.4784 2.5249 2.5249 1.4887 1.3791 Mass of KOH catalyst (neutralising) g 0.1445 0.1482 0.2549 0.2540 0.1496 0.1384 Mass of NaOH catalyst (neutralising) g 0.0852 0.0874 0.1503 0.1498 0.0882 0.0816 Mass of NaOH catalyst (1% of Oil) g 1.0074 1.0027 1.0096 1.0058 1.0049 1.0039

Total mass of catalyst (g) 1.0926 1.0901 1.1599 1.1556 1.0931 1.0855

C001coco-

1-oil C021coco-

1-oil C031coco-

1-oil C002coco-

1-oil C022coco-

1-oil C032coco-

1-oil Oil Properties Mass of feedstock (g) 100.7400 100.2700 100.9600 100.5800 100.4900 100.3900 Mr. of triglyceride (Lauric) (g/moles) 639.0000 639.0000 639.0000 639.0000 639.0000 639.0000 Moles of triglyceride (moles) 0.1577 0.1569 0.1580 0.1574 0.1573 0.1571 Methanol Properties Moles of Methanol (moles) 0.9459 0.9415 0.9480 0.9444 0.9436 0.9426 Mr. of Methanol (g/moles) 32.0000 32.0000 32.0000 32.0000 32.0000 32.0000 Mass of Methanol (g) 30.2693 30.1281 30.3354 30.2212 30.1942 30.1641 Density of Methanol (g/ml) 0.7910 0.7910 0.7910 0.7910 0.7910 0.7910

Volume of Methanol (ml) 38.2671 38.0886 38.3507 38.2063 38.1722 38.1342

Table A.18 Pretreatment of Waste oil – METHANOLYSIS

20:1methanol to FFA, 10% sulphuric acid.

W001p W021p W031p W002s W022s W032s W023s

Oil Properties . . . . . Mass of feedstock (g) 200.64 200.53 200.1 200.14 200.3 200.26 200.69 Free Fatty Acids (%) 1.6215 5.8907 12.7402 12.0995 6.4738 13.0323 1.0193 Mass of FFA in stock (g) 3.2534 11.8126 25.4931 24.2159 12.9670 26.0985 2.0456 Mr. of Free fatty Acid (g/moles) 256.42 256.42 256.42 282.46 282.46 282.46 282.46 Moles of Free fatty Acid (moles) 0.0127 0.0461 0.0994 0.0857 0.0459 0.0924 0.0072

Methanol Properties Moles of Methanol (moles) 0.2538 0.9213 1.9884 1.7146 0.9181 1.8479 0.1448 Mr. of Methanol (g/moles) 32 32 32 32 32 32 32 Mass of Methanol (g) 8.1201 29.4832 63.6285 54.8687 29.3808 59.1341 4.6350 Density of Methanol (g/ml) 0.791 0.791 0.791 0.791 0.791 0.791 0.791 Volume of Methanol (ml) 10.2656 37.2733 80.4405 69.3662 37.1438 74.7587 5.8597

Acid Properties Mass of H2SO4 ( 10% of FFA) g 0.3253 1.1813 2.5493 2.4216 1.2967 2.6098 0.2046 Density of H2SO4 (g/ml) 1.8 1.8 1.8 1.8 1.8 1.8 1.8

Appendix

180

Volume of H2SO4 (ml) 0.1807 0.6563 1.4163 1.3453 0.7204 1.4499 0.1136

Molecular weight of palitic acid 256.42 Molecular weight of oliec acid 282.46

Table A.19 Transesterification of Pretreated Oil

Catalyst to neutralise leftover FFA before transesterification Catalyst W001p W021p W031p W002s W022s W032s W023s

Mass of pretreated oil (g) 100.5200 100.6100 100.7500 100.1600 100.8800 100.4400 100.8900 Acid Value (mg KOH/g) 0.9953 0.0000 0.0000 0.0000 0.0000 0.0000 1.8398 Mass of KOH catalyst (neutralising) g 0.1001 0.0000 0.0000 0.0000 0.0000 0.0000 0.1856 Mass of NaOH catalyst (neutralising) g

0.0590 0.0000 0.0000 0.0000 0.0000 0.0000 0.1095

Mass of NaOH catalyst (1% of Oil) g 1.0052 1.0061 1.0075 1.0016 1.0088 1.0044 1.0089 Total mass of catalyst (g) 1.0642 1.0061 1.0075 1.0016 1.0088 1.0044 1.1184

Oil Properties Mass of feedstock (g) 100.5200 100.6100 100.7500 100.1600 100.8800 100.4400 100.8900 Mr. of triglyceride (palmitic) (g/moles) 806.7360 806.7360 806.7360 885.4300 885.4300 885.4300 885.4300 Moles of triglyceride (moles) 0.1246 0.1247 0.1249 0.1131 0.1139 0.1134 0.1139 Methanol Properties Moles of Methanol (moles) 0.7476 0.7483 0.7493 0.6787 0.6836 0.6806 0.6837 Mr. of Methanol (g/moles) 32.0000 32.0000 32.0000 32.0000 32.0000 32.0000 32.0000 Mass of Methanol (g) 23.9234 23.9448 23.9781 21.7191 21.8752 21.7798 21.8774 Density of Methanol (g/ml) 0.7910 0.7910 0.7910 0.7910 0.7910 0.7910 0.7910 Volume of Methanol (ml) 30.2445 30.2715 30.3137 27.4577 27.6551 27.5345 27.6579

Molecular weight of tripalmitoyl glycerol 806.736 Molecular weight of trioleoyl glycerol 885.43

Appendix

181

One Step Base Transesterification (Method 2A) and T wo Step Base Transesterification

(Method 2B)

– Coconut oil Methyl and ethyl esters

– Soybean oil methyl and ethyl esters

– Canola oil methyl and ethyl esters

Table A.20 Coconut oil - METHANOLYSIS

Oil Properties C001coco C021coco C031coco C002coco C022coco C032coco Mass of feedstock (g) 100.0600 100.4500 100.2100 100.1300 100.1500 100.1900 Mr. of triglyceride (Lauric) (g/moles) 639.0000 639.0000 639.0000 639.0000 639.0000 639.0000 Moles of triglyceride (moles) 0.1566 0.1572 0.1568 0.1567 0.1567 0.1568 Methanol Properties Moles of Methanol (moles) 0.9395 0.9432 0.9409 0.9402 0.9404 0.9408 Mr. of Methanol (g/moles) 32.0000 32.0000 32.0000 32.0000 32.0000 32.0000 Mass of Methanol (g) 30.0650 30.1822 30.1100 30.0860 30.0920 30.1040 Density of Methanol (g/ml) 0.7910 0.7910 0.7910 0.7910 0.7910 0.7910 Volume of Methanol (ml) 38.0088 38.1570 38.0658 38.0354 38.0430 38.0582 Catalyst Mass of NaOH catalyst (1% of Oil) g 1.0006 1.0045 1.0021 1.0013 1.0015 1.0019 Molecular weight of trilauryl glycerol 639.00

Table A.21 Coconut oil – ETHANOLYSIS

Oil Properties C001coco C021coco C031coco C002coco C022coco C032coco Mass of feedstock (g) 100.2600 100.2400 100.1800 100.0200 100.4200 100.1000 Mr. of triglyceride (lauric) (g/moles) 639.0000 639.0000 639.0000 639.0000 639.0000 639.0000 Moles of triglyceride (moles) 0.1569 0.1569 0.1568 0.1565 0.1572 0.1567 Methanol Properties Moles of Methanol (moles) 0.9414 0.9412 0.9407 0.9392 0.9429 0.9399 Mr. of Methanol (g/moles) 46.0000 46.0000 46.0000 46.0000 46.0000 46.0000 Mass of Methanol (g) 43.3048 43.2962 43.2702 43.2011 43.3739 43.2357 Density of Methanol (g/ml) 0.7890 0.7890 0.7890 0.7890 0.7890 0.7890 Volume of Methanol (ml) 54.8857 54.8747 54.8419 54.7543 54.9733 54.7981 Catalyst Mass of KOH catalyst (0.5% of Oil) g 0.5013 0.5012 0.5009 0.5001 0.5021 0.5005

Molecular weight of trilauryl glycerol 639.00

Appendix

182

Table A.22 Soybean oil - METHANOLYSIS

Oil Properties C001soy C021soy C031soy C002soy C022soy C032soy Mass of feedstock (g) 200.0000 200.5700 200.9600 200.0300 200.7100 200.2400 Mr. of triglyceride (oleic) (g/moles) 885.43 885.43 885.43 885.43 885.43 885.43 Moles of triglyceride (moles) 0.2259 0.2265 0.2270 0.2259 0.2267 0.2262 Methanol Properties Moles of Methanol (moles) 1.3553 1.3591 1.3618 1.3555 1.3601 1.3569 Mr. of Methanol (g/moles) 32.0000 32.0000 32.0000 32.0000 32.0000 32.0000 Mass of Methanol (g) 43.3688 43.4924 43.5769 43.3753 43.5227 43.4208 Density of Methanol (g/ml) 0.7910 0.7910 0.7910 0.7910 0.7910 0.7910 Volume of Methanol (ml) 54.8278 54.9840 55.0909 54.8360 55.0224 54.8936 Catalyst Mass of NaOH catalyst (1% of Oil) g 2.0000 2.0057 2.0096 2.0003 2.0071 2.0024

Table A.23 Soybean oil – ETHANOLYSIS

Oil Properties C001soy C021soy C031soy C002soy C022soy C032soy Mass of feedstock (g) 100.5000 100.4300 100.2300 100.7900 101.0700 100.0300 Mr. of triglyceride (oleic) (g/moles) 885.43 885.43 885.43 885.43 885.43 885.43 Moles of triglyceride (moles) 0.1135 0.1134 0.1132 0.1138 0.1141 0.1130 Methanol Properties Moles of Methanol (moles) 0.6810 0.6806 0.6792 0.6830 0.6849 0.6778 Mr. of Methanol (g/moles) 46.0000 46.0000 46.0000 46.0000 46.0000 46.0000 Mass of Methanol (g) 31.3272 31.3053 31.2430 31.4175 31.5048 31.1806 Density of Methanol (g/ml) 0.7890 0.7890 0.7890 0.7890 0.7890 0.7890 Volume of Methanol (ml) 39.7049 39.6772 39.5982 39.8195 39.9301 39.5192 Catalyst Mass of KOH catalyst (0.5% of Oil) g 0.5025 0.5022 0.5012 0.5040 0.5054 0.5002

Table A.24 Canola oil – METHANOLYSIS

Oil Properties C001can C021can C031can C002can C022can C032can Mass of feedstock (g) 200.7400 205.0800 200.5800 202.5400 200.9400 202.9700 Mr. of triglyceride (oleic) (g/moles) 885.43 885.43 885.43 885.43 885.43 885.43 Moles of triglyceride (moles) 0.2267 0.2316 0.2265 0.2287 0.2269 0.2292 Methanol Properties Moles of Methanol (moles) 1.3603 1.3897 1.3592 1.3725 1.3616 1.3754 Mr. of Methanol (g/moles) 32.0000 32.0000 32.0000 32.0000 32.0000 32.0000 Mass of Methanol (g) 43.5292 44.4703 43.4945 43.9195 43.5726 44.0128 Density of Methanol (g/ml) 0.7910 0.7910 0.7910 0.7910 0.7910 0.7910 Volume of Methanol (ml) 55.0306 56.2204 54.9868 55.5241 55.0855 55.6420 Catalyst Mass of NaOH catalyst (1% of Oil) g 2.0074 2.0508 2.0058 2.0254 2.0094 2.0297

Appendix

183

Table A.25 Canola oil – ETHANOLYSIS

Oil Properties C001can C021can C031can C002can C022can C032can Mass of feedstock (g) 101.2700 100.2400 101.0200 100.7400 101.1100 100.6300 Mr. of triglyceride (oleic) (g/moles) 885.43 885.43 885.43 885.43 885.43 885.43 Moles of triglyceride (moles) 0.1144 0.1132 0.1141 0.1138 0.1142 0.1137 Methanol Properties Moles of Methanol (moles) 0.6862 0.6793 0.6845 0.6827 0.6852 0.6819 Mr. of Methanol (g/moles) 46.0000 46.0000 46.0000 46.0000 46.0000 46.0000 Mass of Methanol (g) 31.5672 31.2461 31.4892 31.4020 31.5173 31.3677 Density of Methanol (g/ml) 0.7890 0.7890 0.7890 0.7890 0.7890 0.7890 Volume of Methanol (ml) 40.0091 39.6022 39.9103 39.7997 39.9459 39.7562 Catalyst Mass of KOH catalyst (0.5% of Oil) g 0.5064 0.5012 0.5051 0.5037 0.5056 0.5032

Base Neutralisation One Step Base Transesterification (Method 3)

– Coconut oil ethyl esters

– Waste oil ethyl esters

–

Table A.26 Transesterification of Waste Oil - ETHANOLYSIS

Catalyst KOH W001p W021p W031p W002s W022s W032s W003s W023s W033s

Mass of waste oil (g) 100.3300 100.3800 100.2900 100.3100 100.9900 100.4900 100.1900 100.7000 100.7000 Acid Value (mg KOH/g) 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 Mass of KOH catalyst (neutralising) g 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 Mass of KOH catalyst (1% of Oil) g 1.0033 1.0038 1.0029 1.0031 1.0099 1.0049 1.0019 1.0070 1.0070 Total mass of catalyst (g) 1.0033 1.0038 1.0029 1.0031 1.0099 1.0049 1.0019 1.0070 1.0070

Oil Properties Mass of feedstock - waste oil (g) 100.3300 100.3800 100.2900 100.3100 100.9900 100.4900 100.1900 100.7000 100.7000 Mr. of triglyceride (palmitic) (g/moles) 806.7360 806.7360 806.7360 885.4300 885.4300 885.4300 885.4300 885.4300 885.4300 Moles of triglyceride (moles) 0.1244 0.1244 0.1243 0.1133 0.1141 0.1135 0.1132 0.1137 0.1137 Methanol Properties Moles of Ethanol (moles) 0.7462 0.7466 0.7459 0.6797 0.6843 0.6810 0.6789 0.6824 0.6824 Mr. of Ethanol (g/moles) 46.0000 46.0000 46.0000 46.0000 46.0000 46.0000 46.0000 46.0000 46.0000 Mass of Ethanol (g) 34.3248 34.3419 34.3112 31.2679 31.4799 31.3240 31.2305 31.3895 31.3895 Density of Ethanol (g/ml) 0.7890 0.7890 0.7890 0.7890 0.7890 0.7890 0.7890 0.7890 0.7890

Volume of Ethanol (ml) 43.5042 43.5259 43.4869 39.6298 39.8985 39.7009 39.5824 39.7839 39.7839 Tripalmitoyl glycerol 806.736

trioleoyl glycerol 885.43

Appendix

184

Table A.27 Transesterification of Coconut Oil - ETHANOLYSIS

Catalyst KOH C001coco C021coco C031coco C002coco C022coco C032coco

Mass of coconut oil (g) 100.3400 100.1800 100.5800 100.2300 100.5900 100.2600 Acid Value (mg KOH/g) 10.05369 9.877451 9.861161 8.87956 11.94628 11.95847 Mass of KOH catalyst (neutralising) g 1.0088 0.9895 0.9918 0.8900 1.2017 1.1990 Mass of KOH catalyst (1% of Oil) g 1.0034 1.0018 1.0058 1.0023 1.0059 1.0026

Total mass of catalyst (g) 2.0122 1.9913 1.9976 1.8923 2.2076 2.2016

Oil Properties Mass of feedstock - waste oil (g) 100.3400 100.1800 100.5800 100.2300 100.5900 100.2600 Mr. of triglyceride (oleic) (g/moles) 639.0000 639.0000 639.0000 639.0000 639.0000 639.0000

Moles of triglyceride (moles) 0.1570 0.1568 0.1574 0.1569 0.1574 0.1569

Methanol Properties

Moles of Ethanol (moles) 0.9422 0.9407 0.9444 0.9411 0.9445 0.9414 Mr. of Ethanol (g/moles) 46.0000 46.0000 46.0000 46.0000 46.0000 46.0000 Mass of Ethanol (g) 43.3393 43.2702 43.4430 43.2918 43.4473 43.3048 Density of Ethanol (g/ml) 0.7890 0.7890 0.7890 0.7890 0.7890 0.7890

Volume of Ethanol (ml) 54.9295 54.8419 55.0608 54.8692 55.0663 54.8857 trilauryl glycerol (C39H74O6)

Appendix

185

ANALYSIS OF BIODIESEL

Table A28 Peak Areas of Coconut Oil Methyl Ester from Its Respective Fatty Acids. (GC-FID Analysis)

Samples C8 C10 C12 C14 C16 IS C18:0 C18:1 C18:2

Peak Areas (mvs-1) 1 C001coco-2A-WBDM 10215.54 8059.59 59282.94 20161.48 9008.21 23700.01 2736.90 5673.82 1213.12 2 C001coco-2B-WBDM 10114.54 8028.96 60056.33 20857.75 9485.01 25632.54 2944.62 6037.05 1281.11 3 C001coco-1-WBDM 7265.51 7047.01 56975.60 20670.90 9707.00 24333.47 3060.19 6369.89 1296.70

4 C021coco-2A-WBDM 9897.43 7659.50 53610.55 17205.11 7648.62 21369.39 2331.06 4920.37 941.41 5 C021coco-2B-WBDM 10001.15 7966.37 60628.70 20521.86 7762.22 21704.26 2612.82 5485.09 1065.61 6 C021coco-1-WBDM 8507.26 8459.70 67078.09 15442.25 7260.49 18882.84 2236.44 4839.08 2954.14





Appendix

186

Table A29 Peak Areas of Coconut Oil Ethyl Ester From Its Respective Fatty Acids. (GC-FID).

Samples C8 C10 C12 C14 C16 IS C18:0 C18:1 C18:2 Peak Areas (mvs -1 )

1 C001coco-2A-WBDE 675.32 423.64 61.70 3278.54 954.69 567.45 26334.57 223.45 678.32 254.63 2 C001coco-2A-WBDE-salt 774.46 606.42 74.30 4317.96 1498.28 694.57 26114.95 236.10 779.69 307.42 3 C001coco-2B-WBDE 143.17 48.00 114.03 271.32 102.42 50.10 28388.09 30.88 55.14 14.57 4 C001coco-2B-WBDE-salt 112.97 48.08 107.65 301.65 114.52 54.69 26531.65 23.33 59.11 13.72 5 C001coco-3-WBDE 6674.18 5905.16 48413.27 17504.08 7221.63 26951.85 2990.29 13394.36 2498.33 6 C001coco-3-WBDE-salt 8146.84 7733.45 53945.37 19126.54 6758.85 23148.51 2761.64 5710.93 1171.28


13 C031coco-2A-WBDE 324.03 159.73 71.77 643.07 200.12 78.93 26626.44 79.59 525.66 56.78 14 C031coco-2A-WBDE-salt 493.75 302.36 19.22 1242.74 214.52 70.07 25520.69 25.88 80.98 36.63 14 C031coco-2B-WBDE 83.32 38.22 93.03 293.50 99.27 42.51 23356.90 19.48 37.70 10.70 15 C031coco-2B-WBDE-salt 61.89 37.49 107.38 255.53 89.02 43.02 26854.45 19.73 43.16 22.47 16 C031coco-3-WBDE 5699.87 36962.02 92.28 38448.41 14115.13 5770.47 22656.30 1369.41 2870.31 719.50 17 C031coco-3-WBDE-salt 5826.36 4987.62 38541.52 13136.01 6145.60 26844.71 2003.97 4108.77 880.34

18 C002coco-2A-WBDE 282.23 210.66 83.59 1405.22 489.72 233.47 21345.78 67.68 152.70 30.12 19 C002coco-2A-WBDE-salt 352.53 273.22 59.63 1637.29 522.66 214.42 22359.10 72.33 154.98 18.21 20 C002coco-2B-WBDE 133.24 36.36 79.85 294.75 104.13 47.32 27339.47 10.26 51.18 8.11 21 C002coco-2B-WBDE-salt 164.69 81.22 92.63 439.09 153.06 69.18 27534.24 25.39 43.47 8.79 22 C002coco-3-WBDE 4404.28 3755.62 32121.40 11966.95 5709.11 20619.96 1779.38 3833.96 757.24

Appendix

187

Continued….

23 C002coco-3-WBDE-salt 3444.03 3221.65 30278.34 11506.59 5557.40 25782.18 1849.07 3844.37 658.46



Appendix

188

Table A30 Peak Areas of Waste Oil Methyl Ester From Its Respective Fatty Acids. (GC Analysis).

Samples 7.74 8.18 8.84 9.14 9.82 10.08 IS 10.75 11.56

Peak Areas (mvs-1 ) 1 W001p-1-WBDM 14.94 43.80 1963.95 194.28 0.00 1750.23 322.05 2 W021p-1-WBDM 63.42 2569.02 264.56 0.00 2398.90 489.02 3 W031p-1-WBDM 11.77 53.01 2370.95 98.39 291.14 2206.69 385.50 4 W002s-1-WBDM 29.98 1350.92 71.05 287.28 344.16 1794.57 307.39 307.00 5 W022s-1-WBDM 37.79 1701.54 86.35 436.66 613.05 2656.67 447.44 36.31 6 W032s-1-WBDM 36.41 1551.48 115.27 4734.29 817.57 2628.78 388.96 44.32 7 W003s-2A-WBDM 33.42 1351.55 194.06 1551.16 620.00 37.92 8 W023s-1-WBDM 12.46 45.35 1961.59 201.28 1965.62 457.46 9 W033s-2A-WBDM 13.34 43.85 1801.87 197.25 2011.74 505.62 25.46

Table A.31 Peak Areas of Waste Oil Ethyl Ester From Its Respective Fatty Acids.

Samples 7.81 8.3 9.04 9.37 10 10.37 10.93is 11.11 1 1.6 11.86 12.02

Peak Areas (mvs-1 ) 1 W001p-3-WBDE 16.22 47.89 2056.50 9.78 190.21 0.00 1756.81 329.88 15.33 1.48 4.00 2 W021p-3-WBDE 11.94 27.31 1202.62 8.83 122.08 0.00 1097.86 214.67 8.78 1.80 2.54 3 W031p-3-WBDE 8.56 31.95 1319.59 56.63 149.69 0.00 1159.60 213.04 7.69 3.36 4.66

4 W002s-3-WBDE 4.48 23.06 874.01 50.44 162.70 159.54 1033.52 182.88 6.83 7.18 4.84 5 W022s-3-WBDE 2.94 19.14 812.12 45.50 199.32 262.89 1167.07 182.52 9.44 8.90 4.31 6 W032s-3-WBDE 5.36 25.72 861.78 43.45 178.32 185.65 1154.98 185.79 8.78 6.23 7.98

7 W003s-3-WBDE 11.41 34.54 1320.66 9.54 181.98 0.00 1452.92 597.88 13.86 28.55 5.19 8 W023s-3-WBDE 11.48 39.70 1635.42 3.02 164.40 2.62 1586.98 377.43 14.41 7.26 5.42 9 W033s-3-WBDE 9.00 29.87 1214.92 4.35 131.92 2.68 1318.26 315.55 12.77 11.60 4.93

Appendix

189

Methyl Oleate

Ethyl esters of Waste Oil

Chromatogram: W033s-3-WBDE

Figure A.1 GC chromatogram of waste oil ethyl ester

Methyl oleate

Chromatogram of methyl ester of waste oil from synthetic method 1:

Figure A.2 GPC chromatogram of waste oil methyl ester

5.00

5.05

5.10

5.15

5.20

5.25

5.30

5.35

5.40

7.0 7.5 8.0 8.5 9.0 9.5 10.0 10.5 11.0 11.5 12.0

7.76 8.25

8.99

10.06

10.42

10.99

11.49

11.74

11.90

Methyl Oleate

Appendix

190

Methyl laurate

Chromatogram of coconut oil methyl ester from synthetic method 1:

Figure A.3 GPC chromatogram of coconut oil methyl ester synthesized using method 1.

Chromatogram of coconut oil methyl ester from synthetic method 2A:

Figure A.4 GPC chromatogram of coconut oil methyl ester synthesized using method 2A.

Methyl Laurate

Methyl Laurate

Appendix

191

Chromatogram of coconut oil methyl ester from synthetic method 2B:

Figure A.5 GPC chromatogram of coconut oil methyl ester synthesized using method 2B.

Ethyl oleate Chromatogram of waste oil ethyl ester from synthetic method 3 :

Figure A.6 GPC chromatogram of waste oil ethyl ester synthesized using method 3.

Methyl Laurate

Ethyl oleate

Appendix

192

Ethyl laurate

Chromatogram of coconut oil ethyl ester from synthetic method 2A:

Figure A.7 GPC chromatogram of coconut oil ethyl ester synthesized using method 2A.

Chromatogram of coconut oil ethyl ester from synthetic method 2B:

Ethyl laurate

Ethyl laurate

Appendix

193

Figure A.8 GPC chromatogram of coconut oil ethyl ester synthesized using method 2B.

Chromatogram of coconut oil ethyl ester from synthetic method 3:

Figure A.9 GPC chromatogram of coconut oil ethyl ester synthesized using method 3.

Ethyl laurate

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