Page 76 - Advances in Eco-Fuels for a Sustainable Environment

Prospects of biodiesel feedstock 3

as an effective ecofuel source
and their challenges

E.F. Aransiola, E.O. Ehinmitola, A.I. Adebimpe, T.D. Shittu, B.O. Solomon
Department of Chemical Engineering, Obafemi Awolowo University, Ile-Ife, Nigeria

3.1 Introduction

The craving for a green environment and searching for alternative fuel for conven-
tional diesel have been the driving tools for the production of biodiesel. The
nonrenewability of this petrol diesel and the ever-growing population of the world
have given rise to its depletion, and it has been projected that a total depletion is pos-
sible in the distant future [1]. Therefore, it is necessary to plan for the future before
the future. This has led to the development of biodiesel as the potential “partner” to
petroleum diesel as an energy source [2]. Biodiesels are renewable ecofuels mainly
produced from biological resources [3]. The inherent merits of biodiesel over petro-
leum diesel are their renewability, environmental friendliness, portability, and
biodegradability [1].
The synthesis of biodiesel starts with the choice of feedstock, as it determines the
quality, yield, and production cost of the biodiesel produced [4, 5]. The feedstock for
biodiesel production can vary from country to country depending on the geographical
locations, agricultural practices, and commercial availability of the source of oil. It has
been found that feedstock alone represents 75% of the overall biodiesel production
cost [6]. Hence, a comprehensive knowledge of some parameters needed for the cul-
tivation of feedstock will serve as a useful guide in estimating the cost that may be
associated with production. Therefore, each feedstock can be evaluated based on cul-
tivation and life-cycle analysis, which include soil type, climate, planting season,
maturity period, diseases and pests, and the lifecycle, as evident in Tables 3.5 and
3.7, for edible oils and nonedible oils, respectively. Therefore, selecting the most via-
ble feedstock is vital to ensure the low production cost of biodiesel.
The feedstock can be categorized as vegetable oil or animal fats. The advent of
vegetable oil as a feedstock for the diesel engine was dated back to the 1900s [4].
It has been reported by most researchers that if raw vegetable oils are used directly
in the diesel engine, engine performance decreases, CO and HC emissions increase,
and NO x emissions decrease accordingly [13]. This now creates the need for further
processing of the vegetable oil via transesterification. This method is normally used to
reduce vegetable oil viscosity. Transesterification is the reversible reaction of a fat or
oil with an alcohol (methanol or ethanol) to form fatty acid alkyl esters and glycerol
[10]. Soybean methyl ester was used as a fuel in the diesel engine of a Dodge truck

Advances in Eco-Fuels for a Sustainable Environment. https://doi.org/10.1016/B978-0-08-102728-8.00003-6
© 2019 Elsevier Ltd. All rights reserved.