ABSTRACT
Biodiesel was produced from the seed oil of Luffa cylindrica.
The oil obtained was transesterified to produce methyl-esters and glycerol. The
percentage oil yield of 36.32% was obtained from Luffa cylindrica seed. Biodiesel
properties of methyl-esters were determined using American
Society for Testing and Materials (ASTM) Standards and compared with
that of petrodiesel. The methyl-ester yield of 92.06 % was obtained from Luffa cylindrica
seed oil. Higher viscosity at 40oC (15.50 mm2/s) was
obtained for the seed oil whereas it was reduced to 3.80 mm2/s after
transesterification which is comparable with that of biodiesel standards. Lower
heating value (29.39 MJ/kg) was obtained for methyl-ester of Luffa cylindrica compared
to 42.85 MJ/kg obtained for petro diesel. Higher pour, cloud and flash points
of 4 oC, 8 oC and 150 oC respectively were
obtained for Luffa cylindrica seed methyl-ester, compared to -12 oC,
-16 oC and 74 oC respectively obtained for petrodiesel. Biodiesel produced from Luffa
cylindrica seed oil had cetane number (71.93),
refractive index (1.465 nm) and relative density (0.88 kg/m2)
which is comparable to biodiesel standard. The chemical properties acid value (0.52
mgKOH/g) and iodine value (57.87 mgI2/g) also compared well with
most standard biodiesel. The seed oil of Luffa cylindrica could be a good
source of biodiesel.
TABLE OF CONTENTS
Title Page – – – – – – – – i
Certification – – – – – – – – – ii
Dedication – – – – – – – – iii
Acknowledgements – – – – – – – iv
Abstract – – – – – – – – – v
Table of Contents – – – – – – – vi
ListofTables – – – – – – – – xi
List of Figures – – – – – – – – xii
List of Abbreviations – – – – – – – – xiii
CHAPTER ONE: INTRODUCTION
1.1 Luffa cylindrica plant – – – – – 2
1.2 Biodiesel – – – – – – 3
1.2.1 Advantages and disadvantages of biodiesel – – 6
1.2.2 Alcohols used in the production of biodiesel – – 7
1.2.3 Methods of biodiesel production – – – 8
1.2.3.1 Single step alkali based transesterification – – 8
1.2.3.2 Two step acid-base catalyzed transesterification 9
1.2.3.2.1 Acid-catalyzed esterification – – – – 9
1.2.3.2.2 Alkaline-catalyzed transesterification – – – 10
1.2.4 Catalysts for biodiesel production – – – 11
1.2.5 Influence of free fatty acids on biodiesel production – 13
1.2.6 Influence of biodiesel composition on fuel properties 13
1.2.6.1 Low temperature operability – – – – 14
1.2.6.2 Kinematic viscosity – – – – – 16
1.2.6.3 Cetane number – – – – – 17
1.2.6.4 Heat of combustion – – – – – 18
1.2.6.5 Lubricity – – – – – – 19
1.2.6.6 Oxidative stability – – – – – 20
1.2.6.7 Contaminants and minor components found in biodiesel – 23
1.2.7 Alternative feedstock for biodiesel production 26
1.2.8 Effects of blending biodiesel with other fuels – – 27
1.2.8.1 Biodiesel-petrodiesel blends – – – – 27
1.2.8.2 biodiesel-alcohol blends – – – – – 29
1.2.8.3 Multi-feedstock biodiesel blends – – – 30
1.2.9 Other uses of biodiesel – – – – – 31
1.3 Important by-product of biodiesel production – – 32
1.4 Aim and objectives of the study – – – 32
1.4.1 Aim of the study – – – – – 32
1.4.2 Objectives of the study – – – – 33
CHAPTER TWO: MATERIALS AND METHODS
2.1 Materials – – – – – 34
2.1.1 Plant material – – – – – – 34
2.1.2 Instrument/Equipment – – – – – 34
2.1.3 Chemicals – – – – – – 35
2.2 Methods – – – – – – 36
2.2.1 Preparation of seeds – – – – – – 36
2.2.2 Extraction of oil from Luffa cylindrica seeds – 36
2.2.3 Recovery of oil from solvent – – – – 36
2.2.4 Physico-chemical properties of the oil extract 36
2.2.4.1 Colour – – – – – – – 36
2.2.4.2 Determination of relative density of the oil extracts- 36
2.2.4.3 Determination of viscosity of the oil extracts — – 37
2.2.4.4 Determination of iodine value of the oils – – 37
2.2.4.5 Determination of peroxide value of the oils — – 38
2.2.4.6 Determination of acid value of the oil – – 38
2.2.4.7 Determination of saponification value of the oil 38
2.2.4.8 Determination of percentage free fatty acids – – 39
2.2.5 Biodiesel production by two step
acid-base transesterification – 39
2.2.5.1 Acid pretreatment – – – – – 39
2.2.5.2 Alkaline transesterification – – – 40
2.2.6 Determination of Fatty acid profile of biodiesel 40
2.2.7 Physico-chemical properties of the biodiesel – – 41
2.2.7.1 Colour – – – – – – – 41
2.2.7.2 Determination of the relative density of the biodiesel 41
2.2.7.3 Determination of the kinematic viscosity of the biodiesel 41
2.2.7.4 Determination of flash point of the biodiesel — – 42
2.2.7.5 Determination of the heat of combustion of the biodiesel 42
2.2.7.6 Determination of refractive index of the biodiesel – 43
2.2.7.7 Determination of cloud point of the biodiesel – – 43
2.2.7.8 Determination of pour point of the biodiesel – – – 43
2.2.7.9 Determination of Ash content of the biodiesel – – – 44
2.2.7.10 Determination of cetane number of the biodiesel – 44
2.2.7.11 Determination of the acid value of the biodiesel – 44
2.2.7.12 Determination of the iodine value of the biodiesel – 45
2.2.7.13 Determination of the peroxide value of the biodiesel 45
CHAPTER THREE: RESULTS
3.1 Percentage yield of Luffa cylindrica seed oil extract – 46
3.2 Physicochemical properties of Luffa cylindrica seed oil 46
3.2.1 Physical properties of Luffa cylindrica seed oil – 46
3.2.2 Chemical properties of Luffa cylindrica seed oil – 47
3.2.3 The Gas chromatographic test of Luffa cylindrica seed oil 48
3.3 Percentage yield of Luffa cylindrica seed oil biodiesel – 49
3.4 Fatty
acid methyl ester composition of Luffa cylindrica seed biodiesel 49
3.5.0 Physicochemical properties of Luffa
cylindrica seed biodiesel – 50
3.5.1 Physical properties of Luffa cylindrica seed biodiesel 50
3.5.2 Chemical properties of Luffa cylindrica seed biodiesel 52
CHAPTER FOUR: DISCUSSION
4.1 Discussion – – – – – 53
4.2 Conclusion – – – – – 61
4.3 Suggestions for Further Studies – – – 62
REFERENCES – – – – – – 63
APPENDICES – – – – – – 80
LIST OF FIGURES
Fig.1.1: Luffa cylindrical seed – – – – – 3
Fig. 1.2: Luffa cylindrical Fruit – – – – – 3
Fig. 1.3: Production of biodiesel – – – – – 4
Fig.1.4:
Transesterification of triacylglycerols to yield fatty acid alkyl esters
(biodiesel) 11
Fig. 3.1: Fatty acids composition of Luffa cylindrica seed oil – – 48
Fig. 3.2: Fatty acid methyl ester composition of Luffa cylindrica seed
biodiesel – 49
LIST OF TABLES
Table 3.1: Physical properties of Luffa cylindrica seed oil – 46
Table 3.2: Chemical properties of Luffa cylindricaseed oil – – 47
Table 3.3: Physical properties of Luffacylindricaseed biodiesel with the international biodiesel and petro diesel standards – – 51
Table 3.4: Chemical properties of Luffacylindrica seed oil biodiesel with the international standard biodiesel and petro diesel – – – 52
LIST OF ABBREVIATIONS
AOAC American
Oil Chemists’ Society
API American
Petroleum Institute
ASTM American
Society for Testing and Material
AV Acid
Value
CFPP Cold
Filter Plugging Point
CFR Code
of Federal Regulations
CI Compression
Ignition
CN Cetane
Number
CP Cloud
Point
DAG Diacylglycerol
EGR Exhaust
Gas Recirculation
EN European
biodiesel standard
FAAE Fatty
acid alkyl ester(s)
FAEE Fatty
Acid Ethyl Esters
FAME Fatty
acid methyl ester(s)
FFA Free
Fatty Acids
GC Gas
Chromatography
IV Iodine
Value
KOH Potassium
hydroxide
LTFT Low
Temperature Flow Test
MAG Monoacylglycerol
OSI Oil
Stability Index
PME Palm
Oil Methyl Ester
PP Pour Point
RFS Renewable Fuel Standard
RSM Response
Surface Methodology
SCR Selective Catalytic Reduction
SME Soybean Methyl Ester
SV Saponification
Value
TAG Triacylglycerol
ULSD Ultra Low Sulphur Diesel
CHAPTER ONE
INTRODUCTION
Biodiesel is an alternative fuel
made from renewable biological sources such as vegetable oil and animal fats
(Raja et al., 2011). Due to the
depleting world’s petroleum reserves, threatening to run out in the foreseeable
future and the increasing environmental concerns, there is a great demand for
alternative sources of petroleum-based fuel including diesel and gasoline
(Sambo, 1981; Munack et al.,
2001). Indiscriminate extraction and increased consumption of fossil fuels have
led to the reduction of the underground-based carbon resources (Ramadhas et al., 2004). Biofuels are produced
from renewable sources; they do not add to the stock of total carbon-dioxide in
the atmosphere. These plant forms remove carbon-dioxide from the atmosphere and
give up the same amount when burnt within a few years. Hence, biofuels are
considered to be “CO2 neutral” (Ramadhas et al., 2004). The primary goals of
National Energy Policy are to increase the energy supplies using mixtures of
domestic resources and to reduce our dependency on imported oil or petroleum.
As a domestic renewable energy source, biomass offers an alternative to
conventional energy sources and supplements national energy security, economic
growth and environmental benefits (Ma and Marcus, 1999). Currently, biodiesel
is considered a promising
alternative due to its renewability,
better gas emission,
non toxicity and
its biodegradability (Hossain et
al., 2010). Plant oil and animal fats contain three ester linkages
between fatty acids and glycerol which makes them more viscous. Among the
techniques applied to overcome the difficulties encountered in using vegetable
or animal oil in engines, transesterification of oil to biodiesel seems the
most promising (Zhang et al.,
2003). The high viscosities of vegetable oils are reduced through the process
of transesterification (Alamu et al.,
2008). The production of biodiesel from edible and non edible oil has
progressively affected food uses, price, production and availability (Rashid et al., 2008). Vegetable oil seeds
that do not compete with traditional food crops are needed to meet existing
energy demands (Xu and Marcus, 2009). Reducing the cost of the feedstock is
necessary for biodiesel’s long-term commercial viability. In order to achieve
production cost reduction and make biodiesel more competitive with petroleum
diesel, low cost feedstocks, such as non-edible oils, waste vegetable oils
could be used as raw material (Xiaohu and
Geg, 2009). In this research therefore, attempt is being made to explore
the oil of Luffa cylindrica seed
from Nigeria in an industrial process for the production of biodiesel.
- Luffa cylindrica plant.
PRODUCTION AND CHARACTERIZATION OF BIODIESEL FROM LUFFA CYLINDRICA SEED OIL
