1.1 BACKGROUND OF THE STUDY
Energy is one basic tool for
development. Its application ranges from domestic uses to industrial
applications for heating furnaces, lighting and running electric motors
and other transport applications. It can thus be referred to as a
cornerstone of economic and social development (El-Saeidy, 2010). Due to
over dependence on biomass and fossil fuel, developing countries like
Nigeria face added dilemmas regarding environmental protection.
Adaramola and Oyewola (2011) opined that Nigeria is endowed with huge
volume of conventional energy resources (crude oil, tar sands, natural
gas and coal) as well as reasonable amount of renewable energy resources
(e.g. hydro, solar, wind and biomass). However, there is energy
shortage in Nigeria because of less potential energy to harness, making
hydropower a less desirable energy source (Okoye, 2007). Projected
refining capacity only supports 445,000 barrels a day and actual output
of these refineries is far below capacity (Okoye 2007).
Scarcity of petroleum and coal threatens
supply of fuel throughout the country.This and problems associated with
poorpetroleum products combustion has led to research on renewable
energy resources. Solar energy, wind energy, different thermal and hydro
sources of energy, biogas are all renewable energy resources. Biogas is
distinct from other renewable energiesbecause of its unique
characteristics of using, controlling and collecting organic wastes and
at the same time producing fertilizer and water for use in agricultural
irrigation. Biogas does not have any geographical limitations it does
not require advanced technology for producing energy.It is very simple
to use and apply(Okafor., 2010).
Fossil fuel is one of the principal
sources of energy. 86% of all the energy consumed comes from fossil
fuels(Kaliyan and Morey , 2009). There are many problems associated with
fossil fuels such as high costs and fluctuation of prices, increase in
demand, disruption in supply, and environmental pollution. These
problems arise because fossil fuels give off carbon dioxide when burnt
thereby causing a greenhouse effect. It is therefore a major
contributory factor to global warming experienced today.
Agricultural residues and animal wastes
are increasingly being diverted for use as domestic fuel to displace
fossils fuel and reduce environmental pollution and reduce emission of
greenhouse gases. Cassava solid wastes, amongst other plant wastes have
been widely used(Oladeji, 2012). Agricultural residues in their natural
forms cannot yield desired result as they are mostly loose and are of
low density. More so, their combustion cannot be effectively controlled
(Oladeji, 2012). Agricultural residues are thus combined with animal
wastes and used in production of biogas.
Biogas is a mixture of methane and
carbon dioxide, produced by the breakdown of organic waste by bacteria
without oxygen (anaerobic digestion). It contains methane and carbon
(IV) oxide with traces of hydrogen sulphide and water vapour. It burns
with pale blue flame and has a calorific value of between 25.9-30J/m3
depending on the percentage of methane in the gas. Biogas production is
a profitable means of reducing or even eliminating the menace and
nuisance of urban wastes in many cities in Nigeria.Consequently, biogas
can be utilized in all energy consuming applications designed for
1.2 PROBLEM STATEMENT
Energy consumption in Nigeria increases
on a relatively high rate. On a global scale. (Iywayemi, 2011)Opined
that the Nigerian energy industry is one of the mostinefficient in
meeting the needs of its customers. Poor energy supply has led to energy
scarcity and fluctuation in prices. This is most evident in the
persistent disequilibrium in the markets for electricity and petroleum
products, especially kerosene and diesel. The dismal energy service
provision has adversely affected living standards of the population and
exacerbated income and energy poverty in an economy where the majority
of the people live on less than 2USD a day.
Coupled with high level of environmental
pollution and contamination as a result of present poor management of
solid wastes, call for the design and fabrication of a simple, low cost
and effective device for the management of the selected solid wastes on
one hand and production of fuel (Biogas) on another hand. Anaerobic
fermentation is a simple and low cost process which can be economically
carried out in rural areas where organic wastes are generated aplenty
which otherwise pollute environment and pose health hazards (Labatut A. ,
Unfortunately, biogas technology has not
been optimally used on large scale in Nigeria compared with the level
as obtained from reports in other countries as China, Korea and
Philippines. According to Ezeokoye et al (2013)
there is need to popularize biogas technology in Nigeria in view of
large population of brewery plants and agricultural. This is to provide
effective utilization of brewery effluents and good check of
environmental pollution caused by its disposal. This
project is therefore meant to come up with a prototype design and
fabricated unit that will optimally produce biogas for household in
Delta state and Nigeria as a whole.The large quantities of agricultural
residues produced in Nigeria can play a significant role in meeting her
1.3 AIM AND OBJECTIVES OF STUDY
1.3.1 Aim of the Study
The aim of this project is to design and
fabricate a medium sized household biogas plant, the developed plant
will operate on animal wastes, household waste and any other
decomposable waste as feeds.
1.3.2Objectives of the Study
The specific objectives are to:
- To collect waste from bioorganic raw materials.
- Optimization and characterization of substrates.
- To design and fabricate a prototype biogas plant for household use.
- To test the biogas machine with the optimal solution.
- To produce manure as by-product of the process that can be used for backyard farming.
1.4 Justification for the Research
Biogas is a form of energy produced when
organic materials such as animal excrement or products that are left
over from agriculture are fermented easily and at low cost. The
advantage of biogas is that it replaces other energy sources for example
charcoal, firewood, electricity, liquid petroleum gas and oil. After
animal excrement had been fermented in the gas plant it becomes a good
quality and odorless substrate, which is better than fresh manure in
improving the soil for the agriculture. As an energy source, it prevents
deforestation and animal excrement from causing pollution, smell, flies
and water pollution in the community. Further, problem of agricultural
waste disposal is posing challenges to the farmers and to the general
public as this waste constitutes a nuisance to the environment andis an
eyesore to the public. Therefore if these wastes could be used to
generate energy, it would be a welcomed solution to the problem of waste
pollution, disposal and control (Enweremaduet al., 2008a).
Nowadays the use of bio-gas has spread
from small farms to big animal farms. It is expected that biogas will be
a significant source of energy in the future to preserve the
environment, solve the pollution problem and to promote better health to
agriculture and community.
1.5 Scope of the Study
This study is limited to the production
of biogas from cow dung from Uti cattle market, chicken droppings from
the poultry section (deep litter) in Agbarho, Delta State.