Introduction
In today’s energy demanding life style, there is a need for
exploring and exploiting new sources of energy that are renewable,
as well as, eco-friendly. The renewable energy resource systems
such as solar, wind, hydro wave, geothermal and biomass,
offer attractive prospects because they are unlimited and cheap [1].
Biomass, which is made up of a wide variety of agricultural residues,
is found in large quantity and it is the major contributor to
renewable energy (occupying approximately about 10% of the total
energy) [2]. It is considered as a worldwide valuable energy alternative
to fossil fuels, because it may be converted to a variety of
usable forms of energy such as biogas, and liquid transportation
biofuels [3]. In developing countries, large quantities of cellulosic
biomass such as rice husks and other forms of agricultural residues
(straws, nut shells, fruit shells, fruit seeds, plant stovers, green
leaves, and molasses) are produced annually but are vastly underutilized
[4]. Thus, agricultural biomass abounds in the rural and
sub-urban areas and contributes to major environmental pollution
[5]. In Nigeria alone, it has been estimated that about 227,500 tons
of fresh animal wastes is produced daily.