Abstract
Biodiesel is a biodegradable, environment friendly, renewable and energy efficiency fuel. It is becoming the most prominent alternative to petro-diesel. Due to current environmental concerns, quality and properties of biodiesel have to be optimized to remove its limitations. The use of oxygenates additives have proved to play such important role. The purpose of this research work was to compare the effects of oxygenates on biodiesel properties such as viscosity, heat content, density, specific gravity, and flash point, pour and cloud point. Tiger and neem oil were extracted from tiger and neem seed and were used to produce biodiesel. The properties of produced biodiesel were studied and compared to ASTM standards. Oxygenates additives (methanol, ethanol and diethyl ether) were added to the biodiesel at different ratios (10%, 20% and 30%) to study their effect on the quality of biodiesel produced. The kinematic viscosity of pure Neem Oil Methyl ester (NOME) and Tiger oil Methyl Ester (
CHAPTER ONE
1.0 Introduction
Depletion of fossil fuels, increasing in greenhouse effects and evolution in energy demands have led to the search for new alternatives to fossil fuels. Researchers proved that many sources of fossil-fuels around the world are nearly close to their maximum production. This simply means that fossil-fossil is not a sustainable source of energy and there is a limited supply of it (Sivalakshmi, 2011).The only solution to this issue was to look and develop alternatives sources of energy (biofuel). Among biofuels alternatives, biodiesel was found to be the most effective one. Many researches have studied on advantages of biodiesel as biofuel, its production and characterization.
1.1. Biodiesel
Biodiesel is a biodegradable, environment friendly, renewable, energy efficient fuel that is used as a substitute of fossil fuel to solve the crisis in fossil fuel diminution and environmental degradation. It is known that biodiesel has ability to be used as pure (Vijayan V, 2013). However, due to the current concerns on the environment; properties of biodiesel have to be improved in order to reduce problems related to its fuel properties. Because of this, recent researches are not only interested in biodiesel production, but maximization of the biodiesel quality and characteristics.
Therefore, in this project, we will look at how biodiesel properties can be improved. Recent researches have proved that compounds which contain oxygen in their structure can be used to improve the properties of biodiesel. Oxygenates are among the compounds with oxygen in their chemical structure.
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1.2. Biodiesel over fossil fuel
Currently, production of biodiesel is getting much consideration worldwide. This consideration is due to the fact that it is non-toxic, biodegradable and produces less emission of particulates to the atmosphere. It was reported that any fatty acid sources such as vegetable oil or animal fat oil can be used to produce biodiesel (Elkady, 2009).
It was confirmed that biodiesel is more environmental friendly than fossil fuel. Due to the current issue of climate change, today’s world is more caring on environment. To use biodiesel effectively, its environmental hazards have to be minimized as much as possible, as well as its heat content as an alternative source of energy has to be improved. To match these requirements, oxygenates were found to play such roles (Barminas JT, 2013)
1.3. Tigernut
Tigernut oil is a type of oil extracted from tigernut seed. Tigernut was discovered 400 years ago and since then it has been used as human consumption and livestock. Tigernut (plant of Cyperus esculentus) can be found in almost every part of Nigeria. This plant is now cultivated in Northern Nigeria and it can be found in the markets throughout the year. It is known in Nigeria as Aya in Hausa, Ofio in Yoruba and Akihausa in Ibo. It can be found in three different varieties (black, brown and yellow). Yellow variety is the most preferable one because it can be gotten in bigger size and attractive color. Tigernut has many applications including flavoring agent, in ice cream making and others. Most importantly, its composition such as high fiber and starch content makes it to be a good feedstock for biodiesel production. (Gambo, 2014).
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1.3.1. Composition of dried Tigernut
Constituents Yellow variety (%) Brown variety (%)
Moisture 3.50 3.78
Crude Protein 7.15 9.70
Lipid 32.13 35.43
Crude Fibre 6.26 5.62
Carbohydrates 46.99 41.22
Ash 3.97 4.25
Energy (KJ) 1343 1511
Table 1: Composition of dried Tigernut
1.4 Neem seed
Neem oil is type of oil extracted from neem seed. Neem oil is composed of many biologically active compounds. Neem oil has numerous applications such as in soap making (Neem soap), making drugs and so on (Vinod Vijayan, 2013).
1.5 Biodiesel production
Biodiesel is produced by the reaction of transesterification. Transesterication is the process whereby fat or oil reacts with an alcohol in the presence of a base catalyst to form the mixture of esters and glycerol. The presence of excess alcohol as catalyst drives the production of large amount of biodiesel. After the production of methyl ester and glycerol, the next step is filtration where upper layer is collected as methyl ester and lower layer is glycerin. Biodiesel produced contains much content of alcohol and base. Therefore, this biodiesel must be washed with hot water to obtain pure biodiesel (Singh Yadav, 2013)