COMPARATIVE STUDY ON THE EFFECTS OF OXYGENATES ON BIODIESEL FROM FRESH AND USED COOKING OIL

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Abstract

Biodiesel is a renewable fuel that will soon be fully accepted in the commercial world but there are limitations to its use that need improvement. The use of oxygenated additives have improved the burning/fuel qualities of conventional diesel and gasoline. These oxygenates may also improve the qualities of biodiesel. This paper focuses on comparing the fuel qualities such as the density, specific gravity, heat content, flash point, and kinematic viscosity of oxygenate-biodiesel blends. The biodiesel was produced from fresh and waste cooking oil and they were characterized and compared to ASTM standards. The oxygenated additives (ethanol, methanol and diethyl ether) were blended in the percentages 10, 20, 30 and 40% with biodiesel from fresh and waste oil. The physicochemical properties such as kinematic viscosity, density, specific gravity, flash point and heat content were analyzed for the blends. The density and specific gravity values were within the range of 0.74-0.84 g/ml and 0.76-0.85 respectively. The kinematic viscosities at 40oC were within 3.5-5.0 mm2s-1 after oxygenated additives were added. The blends ignited at 16oC before the flash points could be gotten. The heat content values for the biodiesel from fresh oil increased at 10 and 20% but decreased at 40% while that of biodiesel from waste oil decreased at 10, 30, and 40% for the ethanol and methanol blends. The diethyl ether blend did not show any pattern with increase in addition. The oxygenate addition improved the density, specific gravity, and kinematic viscosity. Oxygenate addition may be a good way of improving the properties of biodiesel                    as shown  in                                 the                 project.

Table of Contents

Abstract………………………………………………………………………………………………………………………….. i

LIST OF TABLES…………………………………………………………………………………………………………. iv

LIST OF FIGURES………………………………………………………………………………………………………… v

LIST OF EQUATIONS…………………………………………………………………………………………………. vii

Acknowledgements………………………………………………………………………………………………………… ix

CHAPTER 1:       Introduction…………………………………………………………………………………………. 1

CHAPTER 2:       Literature Review………………………………………………………………………………….. 6

CHAPTER 3:       Materials and Methods…………………………………………………………………………. 14

CHAPTER 4:       Results and discussion…………………………………………………………………………. 20

CHAPTER 5:       Summary and Conclusion…………………………………………………………………….. 33

References……………………………………………………………………………………………………………………. 34

LIST OF TABLES

Table 1: GC-MS of biodiesel from fresh cooking oil………………………………………………. 21

Table 2: GC-MS of biodiesel from waste cooking oil…………………………………………….. 21

Table 3: Infrared spectra of biodiesel from fresh oil……………………………………………….. 21

Table 4: Infrared spectra of biodiesel from waste cooking oil………………………………….. 22

Table 5: Comparison between the produced biodiesel and ASTM standards…………….. 23

LIST OF FIGURES

Figure 1: Effect of biodiesel use on emissions…………………………………………………………. 3

Figure 2: Schematic representation of biodiesel production pathway…………………………. 4

Figure 3: Effect of ethanol addition to B100 on NOx emission………………………………… 7

Figure 4: effect of 10% Diethyl ether on the CO emissions of B20 fuel blend……………. 8

Figure 5: Effect of 10% on the HC emissions of B20 fuel blend……………………………….. 8

Figure 6: Effect of methanol and ethanol addition on the flash point of biodiesel……….. 9

Figure 7: Effect of Diethyl ether on the density of biodiesel-diesel blendsl………………. 10

Figure 8: Effect of ethanol on the density of biodiesel-diesel blends……………………….. 10

Figure 9: Effect of ethanol on the heating value of B50 fuel…………………………………… 11

Figure 10: Effect of Diethyl ether on biodiesel- diesel blend…………………………………… 11

Figure 11: Effect of ethanol on the kinematic viscosity of B50……………………………….. 12

Figure 12: Effect of Diethyl ether on the Kinematic viscosity of biodiesel-diesel blends

…………………………………………………………………………………………………………………………12

Figure 13: Effect of Diethyl ether on the pour point of biodiesel-diesel blend…………… 13

Figure 14: Effect of ethanol on the pour point of B50 fuel……………………………………… 13

Figure 15: Effect of oxygenate addition on the density BDFO……………………………….. 25

Figure 16: Effect of Oxygenate addition on the density of BDWO…………………………. 25

Figure 17: Effect of oxygenate addition on the specific gravity of BDFO………………… 26

Figure 18: Effect of oxygenate addition on the specific gravity of BDWO………………. 26

Figure 19: Comparison between the kinematic viscosities of fresh and waste oil……….. 28

Figure 20: Effect of oxygenate addition on the kinematic viscosity of BDFO…………… 29

Figure 21: Effect of oxygenate addition on the kinematic viscosity of BDWO…………. 30

Figure 22: Effect of oxygenate addition on the heat content of BDFO……………………. 32

Figure 23: Effect of Oxygenates on the heat content of BDWO……………………………… 32

LIST OF EQUATIONS

Equation 1: Trans-esterification of vegetable oil……………………………………………………… 4

Equation 2: Acid Value……………………………………………………………………………………… 14

Equation 3: Moisture Content……………………………………………………………………………… 15

Equation 4: Specific Gravity……………………………………………………………………………….. 15

Equation 5: Ash Content……………………………………………………………………………………. 16

Equation 6: Density…………………………………………………………………………………………… 16

Equation 7: Percentage Yield……………………………………………………………………………… 17

CHAPTER 1:     Introduction

The recognition of global warming and depletion of fossil fuels has led to the search for other energy options which are environmental friendly and sustainable. Emission of greenhouse gases from fossil fuels has led scientists to turn to biofuels as an alternative source. Biofuels are fuels made from different types of biomass such as cellulose, algal oil, corn, soy, sugar cane, jatropha, camelina, rapseed, animal fat, methane, paper waste and the likes. These sources create different fuels such as bioalcohols, plant based biodiesel and kerosene, biogas, solid biofuels and the likes (Webb & Coates, 2012).

                    Biodiesel

Biodiesel has grown quite a name for itself since its inception in the 20th century. It is a liquid biofuel composed of simple alkyl esters of fatty acids made from the trans- esterification of vegetable oils and animal fats which are renewable and nontoxic. It is known for its production of low greenhouse gases as compared to fossil fuel (Fangrui & Milford, 1999). The biodiesel produced is independent of the starting material which makes any material containing free fatty acids a suitable feedstock (Michael, Andrew, Winnie, & Thomas , 2006).

Biodiesel production has increased considerably in the last thirty years due to its properties that confirm it environmentally suitable. It is now being accepted in the commercial world as several institutions adopt its use such as businesses, governmental

organizations, schools and the likes. This trend is expected to continue over the years to come (Michael, Andrew, Winnie, & Thomas , 2006).

                    Advantages of biodiesel

The advantages of biodiesel over conventional diesel have been proven to be very essential in curbing emissions of carbon dioxide, sulfur oxide, particulate matter, and polycyclic aromatic hydrocarbons due to the fact that it has 10-11% oxygen by weight and allows for complete combustion of the fuel (Arjun, Chris, & Rafiqul, 2008). Its use comes with lower health problems which is possible since it has a reduced emission of carcinogenic substances. The environment is safer even with biofuel spill due to its high degradability and low toxicity (Romano & Sorichetti, 2011). Reports have suggested that the life cycle of carbon dioxide emissions have been cut down to 30% with the use of biodiesel as compared to conventional diesel (Gerard, Bruno, Dominique, Laurent, & Jean-Alain, 2003). As promising as biodiesel is there are limitations to it that need improvement.