INTERNATIONAL JOURNAL OF
ENERGY AND ENVIRONMENT
Volume 1, Issue 6, 2010 pp.1097-1108
Journal homepage: www.IJEE.IEEFoundation.org
ISSN 2076-2895 (Print), ISSN 2076-2909 (Online) ©2010 International Energy & Environment Foundation. All rights reserved.
Kinetics of palm kernel oil and ethanol transesterification
Julius C. Ahiekpor
1
, David K. Kuwornoo
2
1
Centre for Energy, Environment and Sustainable Development (CEESD), P.O. Box FN 793, Kumasi,
Ghana.
2
Faculty of Chemical and Materials Engineering, Kwame Nkrumah University of Science and
Technology (KNUST), Private Mail Bag, Kumasi, Ghana.
Abstract
Biodiesel, an alternative diesel fuel made from renewable sources such as vegetable oils and animal fats,
has been identified by government to play a key role in the socio-economic development of Ghana. The
utilization of biodiesel is expected to be about 10% of the total liquid fuel mix of the country by the year
2020. Despite this great potential and the numerous sources from which biodiesel could be developed in
Ghana, there are no available data on the kinetics and mechanisms of transesterification of local
vegetable oils. The need for local production of biodiesel necessitates that the mechanism and kinetics of
the process is well understood, since the properties of the biodiesel depends on the type of oil use for the
transesterification process. The objective of this work is to evaluate the appropriate kinetics mechanism
and to find out the reaction rate constants for palm kernel oil transesterification with ethanol when KOH
was used as a catalyst. In this present work, 16 biodiesel samples were prepared at specified times based
on reported optimal conditions and the samples analysed by gas chromatography. The experimental mass
fractions were calibrated and fitted to mathematical models of different proposed mechanisms in
previous works.The rate data fitted well to second-order kinetics without shunt mechanism. It was also
observed that, although transesterification reaction of crude palm kernel oil is a reversible reaction, the
reaction rate constants indicated that the forward reactions were the most prominent.
Copyright © 2010 International Energy and Environment Foundation - All rights reserved.
Keywords: Kinetic model, Biodiesel, Palm kernel oil, Transesterification, Rate constant.
1. Introduction
In the year 2000, Ghana consumed about 1.6 million tonnes of petroleum fuel and this figure is estimated
to exceed 4.5 million tonnes by 2020 [1, 2]. Diesel fuel consumption constitutes about 41% of the
petroleum products consumed in the country with consumption growing steadily at an annual rate of
about 5% [3]. Due to the increase of petroleum based fuel price in the past years and also greater
environmental awareness, Ghana government has set the target on renewable energy utilization through a
Strategic National Energy Policy. In this policy, biodiesel will be used to prepare a mixture of 10 %
biodiesel in fossil diesel by the year 2020 [2].
Consequently, it is estimated that Ghana will produce about 0.45 million tonnes of biodiesel annually by
the year 2020, to meet this target. Thus, the research on renewable energy from domestic resources
particularly biodiesel has attracted attention in this country.
Biodiesel can be processed from different methods, however, the most common process for producing
biodiesel is known as transesterification reaction [4]. The transesterification process reacts triglycerides