PRODUCTION OF ETHANOL THROUGH THE FERMENTATION OF REDUCING SUGARS RESULTING FROM THE HYDROLYSIS OF PRETREATED SAWDUST (HARDWOOD)
CHAPTER ONE
INTRODUCTION
1.1 Background of the Study
Lignocellulosic biomass (e.g. sawdust obtained from wood) provides a unique and sustainable resource for environmentally safe organic fuels and chemicals. Furthermore, due to the abundance of lignocellulosic materials, its conversion to ethanol (a biofuel) is considered one of the most important uses of biomass as an energy source in the modern world especially in the United States, Europe and Asia (Kheshgi, 2000).
Sawdust is produced as a small discontinuous chips or small fragments of wood during sawing of logs of timber into marketable sizes. The chips flow from the cutting edges of the saw blade to the floor during sawing operation, hence its name sawdust has hitherto been classified as a waste and a nuisance to man and its environment, but in recent years, researches have shown that sawdusts can be used in the production of biogas, packaging fillers, and lagging materials etc. The ethanol produced from the food crops were called first generation bio ethanol, whereas the ethanol produced from lignocellulosic biomass were called second generation biomass (Naik et al., 2009). But there were some concerns related to the first generation bio ethanol. Some of them were food security in which there was an issue that the use of food crops will increase the food prices. Greenhouse gases balance also seems to shift as the production of bio ethanol involves more and more food crops. Some environmental concern shows that bio ethanol production from crops might affect the biodiversity and water preservation. The quest for alternative energies has provided many ways to produce electricity, such as wind farms, hydropower, or solar cells. However, about 40% of the total energy consumption is dedicated to transports and in practice requires liquid fuels such as gasoline, diesel fuel, or kerosene. These fuels are all obtained by refining petroleum. This dependency on oil has two major drawbacks, burning fossil fuels such as oil contributes to global warming and importing oil creates a dependency on oil producing countries(Sadler, 2004).
Again, ethanol produced from biomass would be of great benefit to the transportation sector where it is assumed that two-third of Nigeria’s gasoline is consumed. Globally, fossil fuels are being threatened out of dominance over other fuels by the negative effects of fossil fuels products on the environment e.g. the release of greenhouse gases like carbon dioxide that contribute to global warming.
