ETHANOL BIO-FUEL PRODUCTION USING YAM PEELS
ABSTRACT
This project work is based on the production of bioethanol as an alternative source of fuel using yam peels as raw materials. The Bioethanol was produced by fermentation of the Cassava and yam peels with the aid of the enzymes Zymomonas mobilis and Saccharomyces cerevisiae at 28⁰C for 5 days. The fermented liquid was distilled at 78⁰C and the quantity of bioethanol was determined. The use of Glocophylum seplarium and Pleurotus ostreatus for hydrolysis of the peels and Zymomonas mobillis and Saccharomyces cerevisiae for fermentation of 20g of cassava and yam peels yielded a peak mass and percentage yield(concentration) of 26.5g/cm3 (12.2%) and 20.1g/cm3 (9.3%) respectively. When 35g of substrate was used, d yam peels produced a mass 28.1g/cm3 (12.3%) of bioethanol. When 50g of substrate was used, cassava and yam peels produced a mass of 55.2g/cm3 (23%) and 46.6g/cm3 (19.3%) of bioethanol. This study reveals that bioethanol can be produced from cassava and yam peels with maximum yield from cassava peels as a result of the presence of higher starch content when Gloeophylum saplarium, Pleurotus ostreatus, Zymomonas mobillis and Saccharomyces cerevisiae are used.it is recommended that, there should be more restriction on the dump of yam refuse, as regarding its fuel and combustion uses.
TABLE OF CONTENTS
Title page i
DECLARATION ii
CERTIFICATION iii
DEDICATION iv
ACKNOWLEDGEMENTS v
ABSTRACT vi
TABLE OF CONTENTS vii
CHAPTER ONE 1
INTRODUCTION 1
1.1 BACKGROUND OF THE STUDY. 1
1.2 STATEMENT OF THE PROBLEM 3
1.3 OBJECTIVES OF THE STUDY. 4
1.4 SIGNIFICANCE OF THE STUDY. 5
1.5 PURPOSE OF THE STUDY 6
1.6 SCOPE OF THE STUDY. 6
1.7 LIMITATIONS OF THE STUDY 7
1.8 DEFINITION OF TERMS 7
CHAPTER TWO 8
LITERATURE REVIEW. 8
2.1 BIO-ETHANOL PRODUCTION FROM CASSAVA PEELS. 8
2.1.2 BIO- ETHANOL PRODUCTION FROM YAM PEELS 11
2.2 ECONOMIC IMPORTANCE OF BIO-FUELS FROM CASSAVA AND YAM PEELS. 12
2.3 ADVANTAGES AND DISADVANTAGES OF BIO-FUELS. 14
ADVANTAGES: 14
2.4 CHEMICAL COMPOSITION OF YAM PEELS 17
CHAPTER THREE 20
3.0 MATERIALS AND METHODS 20
3.1 MATERIALS USED 20
3.1 SAMPLING AREA. 20
3.2 COLLECTION OF SAMPLES 20
3.3 METHODS 21
3.3.1 Enzyme Hydrolysis of Yam Peels 21
3.3.2 Acid Hydrolysis of Yam Peels 22
3.3.3 Fermentation of Yam Peels 23
3.3.4 Distillation of Yam Peels 24
3.4 PROCEDURE FOR THE DETERMINATION OF THE CONCENTRATION OF ETHANOL 24
3.4.2 Acid Hydrolysis of the Starch component 25
3.4.3 Inoculation of Sample 25
3.4.4 Determination of the Properties of Ethanol 26
3.4.5 Ethanol Yield 26
3.4.6 Flash Point 26
3.4.7 pH Test 27
3.4.8 Density and Specific Gravity Test 27
3.4.9 Viscosity Test 27
3.4.10 Distillation Range Test 28
3.4.11 Electrical Conductivity Test 28
CHAPTER FOUR 29
RESULTS AND DISCUSSION 29
4.1 RESULTS 29
4.2 DISCUSSIONS 30
CHAPTER FIVE 36
5.0 SUMMARY OF FINDINGS, CONCLUSIONS AND RECOMMENDATIONS. 36
5.1 SUMMARY 36
5.2 CONCLUSIONS 36
5.3 RECOMMENDATIONS. 38
REFERENCES. 39
CHAPTER ONE
INTRODUCTION
1.1 BACKGROUND OF THE STUDY.
There is an increasing demand for ethanol production through fermentation processes all over the globe as oil reserves are dwindling and prices are soaring (Brooks, 2008). The high prices have led to energy crises in both developing and developed countries that are oil dependent. According to Naylor et al., (2007), “biofuels will remain a critical energy development target in many parts of the world if petroleum prices exceed US $ 55 – 60 per barrel.” The yam plant is resistant to pest and can be store in the ground for several months after maturity until it is needed, once harvested the storage life of the peel which is not a storage organ or dormancy is limited, and in many countries it is processed for storage by clipping or flaking and drying large amount of dried yams are exported to Europe from Nigeria and other countries as a source of carbohydrate for animal feed. These characteristics make it an excellent small holder crop and one of the most promising sources of starch for alcohol fuel. Also, the foliage can be used for animal feed (and human food in some culture).
Bioethanol is a volatile, flammable, colorless liquid made by fermenting and distilling starch crops. It is a sustainable and renewable form of energy from Agricultural feedstock. These feedstock include waste straw, milk, rice, beetroot, recently grape, banana and dates, sugar cane, potatoes, corn, cassava and yam etc. aside fermentation process, bio-ethanol can be manufactured by the chemical reaction of ethylene with steam. Bio-ethanol is used in cosmetic, thermometer, used as solvent, as a preservative and most importantly, as a motor fuel (additive for gasoline) (FAO 2005-2008). These indispensable uses of bioethanol have led to a high demand for the product but the feedstock (cassava, yam, potatoes, sugar cane, and cereals) used for the first generation biofuels are also used in the food industries. This dichotomy has raised an inevitable tension between the production of food and bioethanol ( Akubor 2000). It is on this basis that this project researches on production of bioethanol from yam and cassava peelings as waste product is being carried out to mitigate the stem competitive demand of Agricultural feedstock for bioethanol production since these feedstock used as food are not even sufficient for the healthy stay of Africans, Amadi, R.A.,(2004). Bioethanol is a microbiological way of converting simple sugar into ethanol and carbon (IV) oxide. Although production level under traditional farming system are around 10 tons per hectare research, into improved varieties and cultural practices has shown that annual yields of 80-100 tons are theoretically possible. The plant is resistant to pest and can be store in the ground for several months after maturity until it is needed, once harvested the storage life of the peel which is not a storage organ or dormancy is limited, and in many countries it is processed for storage by clipping or flaking and drying large amount of dried yams are exported to Europe from Thailand and other countries as a source of carbohydrate for animal feed. These characteristics make it an excellent small holder crop and one of the most promising sources of starch for alcohol fuel. Also, the foliage can be used for animal feed (and human food in some culture).
1.2 STATEMENT OF THE PROBLEM
The concern for an alternative source of fuel has been on the high demand over the years, which contributed to the production of fuel substitutes using cassava and yam peels to produce ethanol fuel. This demands the ultimate technique and idea of producing more fuels for the populace so as to enhance the transportation of goods and services around the country. This in essence is to, minimize fuel scarcity and high cost. Ethanol produce from petroleum (fossil fuel) do have negative effect on the environment. Are there sufficient yams of farmers to cultivate and supply yam for production of ethanol. Most people are afraid that utilizing yam peels for the production of ethanol will lead to food shortage since people also utilize yam and cassava as flour.
1.3 OBJECTIVES OF THE STUDY.
The objectives of the study were stated as follows;
To determine the quality of ethanol fuel obtained from cassava and yam peels compared to the normal petroleum fuel.
To identify the potential of local microbial strains for ethanol production in the area.
To know if there are side-effects associated with ethanol production using the alternative sources of yam and cassava peel.
1.4 SIGNIFICANCE OF THE STUDY.
The research study would be of much importance and benefits that resulted from this study, it will enlighten the people about the usefulness of yam peel (yam waste). This information will assist the people about more waste that are generated every day due to the increase population without making adequate preparation for means of proper disposal thereby constituting nuisance to the environment liens the need to convert some of these waste (yam peel) to useful product (ethanol). It therefore becomes imperative that the searchlight be turned at present to the use of non-food starchy items for the production of fuel ethanol. However, the success of these starch crops as staple foods limits their potential development and general economic growth, for instance, cassava which has become an important bio-fuel crop is a crop crucial for food security especially in Nigeria. The implication of this is that threats to food security exist in the face of growing fuel ethanol demand. Perhaps, the diversion of food resource to bio-fuel production may to a large extent have fuelled the current food crises worldwide (Srinorakutara et al., 2008).
1.5 PURPOSE OF THE STUDY
The purpose of the study is to produce ethanol from yam and cassava peels (waste), and to evaluate the quality of the fuel outcome of the waste materials from the peels.
1.6 SCOPE OF THE STUDY.
This research work involves the collection of cassava and yam peeling from farms and homes respectively. Thereafter an analysis test was made to determine physical and chemical properties of cassava and yam peelings for the production of bio-ethanol as fuel. In all the specific properties in bio-ethanol that may enable it to be used as alternative fuel or used to mix gasoline for purpose of modifications and increase quantity in order to meet market needs. The study will therefore focus its attention on the use of yam peel (yam waste) to produce ethanol since yam peels are easily obtained from all waste dumps in Benin from the dump since they are of no use to the people that dump them there. Hence this research is aimed at evaluating the suitability of using the peels of yam, potato and cassava roots for bio-ethanol production as well as assessing the performance of various substrate pre-treatment processes for the conversion of starch into fermentable sugar and subsequent development of the most effective for optimal ethanol production.
1.7 LIMITATIONS OF THE STUDY
The research study is limited to producing fuel from cassava and yam peels as substitutes for the production of fuels in the market. Also , it is strictly limited by both financial and time factors which restrained the period of the work so far.
1.8 DEFINITION OF TERMS
The meaning of some terms used in the study is explained below;
Yam: The large root of a tropical plant that is cook as food, and it is meant to eat.
Sufficient: To do something enough for a particular purpose.
Ethanol: the types of alcohol or organic compound that is used in alcoholic drinks and are used as fuel for various combustion purposes.