ABSTRACT
his research sought to assess the potential of oils obtained from pumpkin; C. maxima and balsam apple, M. balsamina for biodiesel production. Oils were extracted from the seeds using n-hexane in a soxhlet extractor, then transesterified to biodiesel using single step alkali hydrolysis. The biodiesel so produced were analyzed for their physicochemical and fuel properties using American Standards for Testing and Materials. Fatty acid methyl esters yield was measured using GC-MS. Percentage oil yields were 42.13 ± 0.11 % and 33.21 ± 0.18 % for C. maxima and M. balsamina, respectively. The physicochemical properties of the oils showed high acid values (C. maxima 8.415 ± 0.8 and M. balsamina 9.958 ± 0.5 mg/KOH/g). The percentage oil degumming for C. maxima was 7.6 ± 0.1 % and M. balsamina, 10.12 ± 0.6 %. Some critical fuel parameters for both biodiesel produced from pumpkin and balsam apple showed compliance with American Standards for Testing and Materials and European standard specifications. The result of biodiesel produced from pumpkin showed; Colour 2.1 ± 0.0, cetane number 54.148 ± 0.52, flash point 127 ± 0.00 oC, cloud point 1.1 ± 0.00 oC, pour point -0.3 ± 0.0 oC, sulphur content 0.032 ± 0.01 ppm, kinematic viscosity 4.94 ± 0.0 mm2/s and specific gravity 0.8713 ± 0.0 g/cm3, and for the biodiesel produced from balsam apple; Colour 2.9 ± 0.0, cetane number 57.699 ± 0.23, flash point 137 ± 0.00 oC, cloud point 1.0 ± 0.00 oC, pour point -0.4 ± 0.0 oC, sulphur content 0.021 ± 0.01 ppm, kinematic viscosity 3.82 ± 0.0 mm2/s and specific gravity 0.8615 ± 0.0 g/cm3. The percentage yield of biodiesel from pumpkin and balsam apple oils were 96.78 ± 0.9 and 89.12 ± 0.04 % respectively. Stearic acid methyl ester was dominant with percentage of 14.03 % in BOMEs, which is saturated. The unsaturated methyl esters oleic acid was dominant in the POMEs with a percentage of 33.18 %. The results infer that oils from C. maxima and M. balsamina possess physicochemical properties that are suitable for biodiesel production. The yields of the oils are high enough and comparable with other oils that have been used for biodiesel production.
TABLE OF CONTENTS
Title page i Declaration ii Certification iii Dedication iv Acknowledgement v Abstract vi Table of content vii List of Figure xii List of Table xiii List of Abbreviation xiv List of Appendixes xv CHAPTER ONE INTRODUCTION 1.1 Background 1 1.2 Research Problem Statement 2 1.3 Aim and Objectives of the Research 3 1.3.1 Aim 3 1.3.2 Objective 3 1.4 Justification of the research 3 CHAPTER TWO LITERATURE REVIEW
2.1 Historical Development of Biodiesel 4
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2.2 Oil Seeds Processing 5 2.2.1 Extraction and purification of oil 5 2.3 Methods of Biodiesel Processing 6 2.3.1 Pyrolysis 6 2.3.2 Micro-emulsification 7 2.3.3 Dilution 8 2.3.4 Transesterification 9 2.3.5 Storage and safety of biodiesel 10 2.3.6 Biodegradability of biodiesel 11 2.4 Feed stocks for biodiesel production 11 2.4.1 Pumpkin 14 2.4.2 Balsam apple 14 2.4.3 Edible oils 15 2.4.4 Non-edible oils 16 2.5 Fatty Acid Methyl Esters (FAME) 17 2.6 The influence of operating variables of transesterification on Biodiesel Yield 19 2.6.1 Effect of reaction time and temperature 19 2.6.2 Molar ratio of alcohol to oil and type of alcohol 20 2.6.3 Catalyst type and concentration 22 2.6.4 Purity of reactants 24 2.7 Effect of physicochemical parameters on biodiesel production and quality 24 2.7.1 Mixing intensity 24 2.7.2 Moisture content 24 2.7.3 Free fatty acids and moisture 25
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2.7.4 Stirring 27 2.7.5 Specific gravity 27 2.8 Stability of Biodiesel 28 2.9 Fuel properties and specification of biodiesel 28 2.9.1 Viscosity 30 2.9.2 Flash point 30 2.9.3 Melt point or pour point 30 2.9.4 Cloud point 30 2.9.3 Cetane number 30 2.9.6 Sulphur percentage 31 2.10 Process Theory of Degumming 31 CHAPTER THREE MATERIALS AND METHOD 3.1 Materials 33 3.1.1 Chemical used 33 3.1.2 Equipment used 33 3.2 Sample collection and preparation 34 3.3 Extraction procedure 34 3.4 Determination of physicochemical properties of the vegetable 35 3.4.1 Determination of the saponification value of vegetable oils 35 3.4.2 Determination of acid value of vegetable oils 35 3.4.3 Determination of iodine value of vegetable oils 36 3.4.4 Determination of refractive index of vegetable oils 37 3.4.5 Determination of density of vegetable oils 38
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3.5 Pre-treatment of the oils (acid degumming) 38 3.6 Transesterification 38 3.7 Settling and washing 39 3.8 Determination of Fuel Properties of Biodiesel 39 3.8.1 Determination of pour point 39 3.8.2 Determination of kinematic viscosity 40 3.8.3 Determination of acid value 41 3.8.4 Determination of density 42 3.8.5 Determination of colour 43 3.8.6 Determination of cloud point 43 3.8.7 Determination of flash point 43 3.8.8 Determination of cetane number 44 3.8.9 Determination of specific gravity 44 CHAPTER FOUR RESULTS 4.1 Physicochemical properties of the vegetable oils 46 4.2 Percentage degumming of the vegetable oils 46 4.3 Fatty acid methyl esters of the biodiesels produced 46 4.4 Fuel properties of BOMEs and POMEs 46 CHAPTER FIVE DISCUSSIONS 5.1 Physicochemical properties 55 5.2 Percentage degumming 58
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5.3 Fatty Acid Methyl Esters 58 5.4 Fuel properties 59 5.5 IR spectra 61 CHAPTER SIX SUMMARY CONCLUSION AND RECOMMENDATION 6.1 Summary 63 6.2 Conclusion 63 6.3 Recommendation 64 6.3.1 Recommendation on the use of the oils produced 64 6.3.2 Recommendation for future work 64 Reference 65 Appendix 75
CHAPTER ONE
INTRODUCTION 1.1 Background There is a need for alternative energy sources to petroleum based fuels due to the depletion of the world’s petroleum reserves, global warming and environmental concerns caused by exploration of oil. One possible alternative to fossil fuel is the use of fuels or diesel produced from oils of plant origin like vegetable oils and tree – borne seed oils. These have been found suitable for utilization in diesel engines (Michael and Briggs, 2004). The concept of using vegetable oil as a fuel dates back to 1895 when Dr. Rudolf Diesel developed the first diesel engine to run on vegetable oil. Diesel demonstrated his engine at the World Exhibition in Paris in 1900 using peanut oil as fuel. Vegetable oils have long been promoted as possible alternatives for fossil fuel, but it is only in recent years that systematic efforts have been made to utilize vegetable oil based fuels in engines. Fuel from these sources is technically feasible, environmentally acceptable, and readily available. Different products from vegetable oil such as pure vegetable oil, mixtures of vegetable oil with petroleum diesel as well as biodiesel have been proposed as useful alternatives (Agarwal, 1998). Much of the world uses a system known as the “B” factor to state the amount of biodiesel in any fuel mixture. For example, fuel containing 20 % biodiesel is labeled B20. Pure biodiesel is referred to as B100.
The United State Standard Specification for Biodiesel (ASTM 6751), defines biodiesel as a fuel comprising mono-alkyl esters of long chain fatty acids derived
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from vegetable oils or animal fats which can be used in diesel engines and heating systems (Mittelbach, 1983). Biodiesel has clear benefits in comparison with diesel fuel; it is a renewable fuel, nontoxic, safer to handle, biodegradable, requires no engine modifications and reduces dependency on foreign oil imports (Gerpan, 2006; Carraretto et al., 2004). It also has favorable combustion and emission profiles, for instance emissions of carbon monoxide (CO) and particulate matter decrease by 45 %, hydrocarbon (HC) 70 % but NOx emissions increases by 10 % with 100 % biodiesel (B100) as a fuel (Anon, 2002). The carbon cycle, time for fixation of CO2 from biodiesel is quite small compared to mineral diesel thus contributing more to the reduction of greenhouse gas emissions compared to fossil diesel (Gerpan, 2006; Carraretto et al., 2004; Agarwal et al., 2003). Agarwal et al. (2003), found that biodiesel provides good lubricating properties that can reduce component wear and enhance engine life. However, biodiesel production from edible oils has generated concern as it brings global in balance to the food supply and market demand (Butler, 2006). 1.2 Research Problem Statement
This research intends to solve the problem of biodiesel production from edible sources in order to avoid the in balance in food supply. The plant seeds of pumpkin and balsam apple will be studied as feedstocks for biodiesel production by ascertaining the physicochemical properties in order to have good quality and high yield in the course of producing the biodiesel. However modification in method of biodiesel production will be employed in terms of the following conditions; time, concentration of catalyst, temperature, methanol to oil ratio and biodiesel reactor. The biodiesel to be produce will be studied for fatty acid methyl esters, fuel properties and functional groups to
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see the influence of the physicochemical properties and modifications employed in the biodiesel production. 1.3 Aim and objectives of the research 1.3.1 Aim This research work investigates the potentials of pumpkin and balsam apple seed oils as alternative feedstock for biodiesel production.
1.3.2 Objectives
The aim of this research work will be achieved through the following objectives.
i. Extraction and determination of physicochemical properties of the crude oils from pumpkin and balsam apple
ii. Production of biodiesel (methyl esters) by transesterification of the oils and compare to standards
iii. Determination of acid methyl esters and some fuel properties of the biodiesel produced and compare to standards
iv. Characterize the acid methyl esters for different functional groups present and compare to other work.
1.4 Justification The choice of pumpkin and balsam apple seed oils as the plants of interest in this research is based on its non-edibility. It is also available in large quantity in Nigeria. The oil will provide good lubricating properties that can reduce component wear and enhance engine life.
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