1.1 Introduction
Bioethanol production from the corncob was microbiologically analyzed using previous methodology; and the methods employed in this assay included enzyme hydrolysis, fermentation and distillation process as was previously described (Yanase et al., 2005; Oyeleke et al., 2012).
As a prelude to other parts of this study, this chapter will discuss the background upon which this study was initiated, the statement of problems that led to this study, the Aim and Objectives of the study. Others are Significance of the study, Scope of work, Research hypothesis and questions, Limitations of the Study and Definition of technical terms.
1.2 Background of Study
Corn cob, a waste product of corn contains large amount of sugars that can be further utilized to produce various compounds (Cao et al., 1996). The bioconversion of lignocelluloses to biofuel from cheap non-edible materials such as corn cob for renewal energy is imperative. Thus, by varying temperature conditions during the fermentation process, maximum productivity of biofuel on an industrial scale can be optimized. In the brewing industry, production of biofuel is carried out by the fermentation of starchy materials, in which case, sugars are converted into bioethanol with carbon dioxide and water (Hongguang, 2006) as byproducts. For waste plant materials to be valuable, it must be converted to fuel as a sustainable substitute to fossil fuel. Therefore, there is a need for renewable energy resources from non-edible agricultural sources such as corn cob to replace fossil forms. This is because gas emissions from plant feedstock fuel are less than those emitted by fossil forms and thus beneficial to the environment and global warming (Demirbas, 2005; Hongguang, 2006). Bioethanol produced from corn uses only a small part of the plant material, whereby only the starch from the kernel is transformed into bioethanol (Cao et al., 1996).
Several research studies have been carried out on the production of bioethanol from corn cobs through simultaneous saccharification and fermentation of lignocelluloses agricultural wastes by Kluyveromyces marxianus 6556 (Zhang et al., 2009), using Aspergillums Niger and Saccharomyces cerevisae in simultaneous saccharification and fermentation (Zakpaa et al., 2009) and from Lignocellulosic Biomass (Kumar et al., 2009). Corn however, is a main staple food in South Africa with an annual production of 8.04 million tons (Adesanya and Raheem, 2009). The cobs produced from corn are mainly used as manure for agricultural production.
According to the report of Latif and Rajoka (2001), modern biotechnology allows the use of such lignocelluloses substrates as corn cobs in the production of chemicals and fuels, utilizing microorganisms. It has been shown that when corn is used for bioethanol production at higher temperatures, yeast cells die resulting in a decrease in alcohol yield when the pulp is concentrated, while optimal temperature for maximum productivity occurs at 32°C (Araque et al.,2008). It is therefore, necessary to select the optimum temperature at which yeast strains can ferment the sugars from lignocelluloses material.
The Simultaneous Saccharification and Fermentation (SSF) process has been identified as economically viable for the conversion of these substrates to fermentation products (Cao et al., 1996). Conversion of glucose and xylose to ethanol by coyeast strains has been successfully obtained by (Taniguchi et al., 1997) using a respiratory deficient mutant of Saccharomyces cerevisiae and Pitchiastipitis. Pichiastipitis strains ferment xylose at a high capacity of 57 g L−1 than any other yeast, was poured into two different 1000 cm3 volumetric flasks; provided the pH is maintained at between 4.5 and 6 and 500 cm3 of 5% H2SO4 was added into each flask (to temperature of 25-26°C (Jeffries et al., 2007). According to Jeffries et al. (2007), maximum yield of ethanol is obtained when a mixture of S. cerevisiae and P. stipitis are introduced into a medium containing both glucose and xylose. The amount of bioethanol produced therefore, depends on the optimal temperature which, invariably influence sugar utilization by yeast cells (Mwesigye and Barford, 1996). It is obvious several microorganisms have used in the production of bioethanol but none has utilized a combination of S. cerevisiae and P. stipitis in the production of bioethanol from corn cobs. This study, therefore, utilized an agricultural waste material (corn cobs) in the production of bioethanol as a cheap but effective alternative fuel source to power automobile. Furthermore, time and temperature in the bioethanol production process using the two yeast strains (S. cerevisiae and P. stipitis) were optimized.
Therefore, in Nigeria where the research was carried out, the activities that was conducted is to know the Utilization of Corn Cob for Bioethanol Production.
1.3 Statement of the Problem
The year 2000 was set as a target date for the attainment of food self sufficiency by all African countries in the action plan agreed upon in Lagos, Nigeria (Salih, 1994). However, roughly 5 years after the deadline, little or nothing had been achieved. This failure is evident by the excess capacity in the agro industrial sector; rapid increase in food prices and the gradual resort to food importation among others. Rapid growth in agriculture is essential for broad based economic growth, but acceleration in agricultural growth requires sound use of science and technology embodied in improved seed, fertilizer, agrochemical and other agronomic practices. However without an efficient and cost effective supply of these inputs at the farm gate, science based growth in agricultural productivity cannot be achieved.
1.4 Aim and Objectives of Study
The aim of the study is to assess the Utilization of Corn Cob for Bioethanol Production. In achieving this aim, the following specific objectives were laid out as follows:
- To produce bioethanol from corn cobs wastes
- To identify the usefulness of corn cob for bioethanol production
1.5 Significance of Study
The study will be beneficial to the environment and global warming (Demirbas, 2005; Hongguang, 2006). Bioethanol produced from corn uses only a small part of the plant material, whereby only the starch from the kernel is transformed into bioethanol (Cao et al., 1996).
This study will be of immense benefit to other researchers who intend to know more on this study and can also be used by non-researchers to build more on their research work. This study contributes to knowledge and could serve as a guide for other study.
1.6 Scope of Study
The study focuses on the Utilization of Corn Cob for Bioethanol Production in Sokoto State, Nigeria.
1.7 Limitations of the Study
During the course of this study, many things militated against its completion, some of which are:
- Time Constraint: The time frame given to accomplish this project was very short due to school academic calendar and it was carried out under pressure which made the researcher not to implement some necessary features.
- Research material: availability of research material is a major setback to the scope of the study.
- Frequent power failure: This made the researcher append more money on fuel to ensure sustainable power.
- Financial Constraint: Insufficient fund tends to impede the efficiency of the researcher in sourcing for the relevant materials, literature or information and in the process of data collection (internet).
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