Scientific Research and Essay Vol.3 (7), pp. 308-311, July 2008 Available online at http://www.academicjournals.org/SRE ISSN 1992-2248 © 2008 Academic Journals Full Length Research Paper Characterization of palm-kernel oil biodiesel produced through NaOH-catalysed transesterification process O. J. Alamu 1 *, T. A. Akintola 2 , C. C. Enweremadu 3 and A. E. Adeleke 1 1 Department of Mechanical Engineering, University of Agriculture, PMB 2240, Abeokuta, Nigeria. 2 Olabisi Onabanjo University, Ibogun Campus, Ogun State, Nigeria. 3 Ladoke Akintola University of Technology, Ogbomoso, Nigeria. Accepted 17 June, 2008 Palm kernel oil (PKO) biodiesel was produced through transesterification of PKO with ethanol using sodium hydroxide (NaOH) catalyst. The biodiesel was characterized as alternative fuel for diesel engine through ASTM standard fuel tests. The transesterification process using 100 g PKO, 20.0% ethanol (wt% PKO), 1.0% NaOH, 60 o C reaction temperature and 90 min reaction time yielded average 95.8% PKO biodiesel for three replications. Fuel tests conducted on the biodiesel showed 85.06% reduction of viscosity over its raw PKO at 40 o C. Higher specific gravity, cloud and pour points were obtained compared to that of petroleum diesel. Results obtained are in good agreement with published data for other vegetable oil biodiesel as well as various international standards for biodiesel fuel. Key words: Fuel, ethanol, palm kernel oil, biodiesel, renewable energy. INTRODUCTION Modern biofuels have been reported as a promising long- term renewable energy source which has potential to address both environmental impacts and security con- cerns posed by current dependence on fossil fuels (Batidzirai et al., 2006; Alamu et al., 2007a; Gupta et al., 2007). Fossil fuels such as petroleum, coal and natural gas, which have been used to meet the energy needs of man are associated with negative environmental impacts such as global warming (Munack et al., 2001; Saravanan et al., 2007). Besides, supply of these non-renewable energy sources is threatening to run out in a foreseeable future (Sambo, 1981; Munack et al., 2001). It has been widely reported that not less than ten major oil fields from the 20 largest world oil producers are already exper- iencing decline in oil reserves. Recently published data also revealed a total of 29 major world oil producing countries already experiencing declining oil reserves from year 2005 to 2007 (EIA, 2007; Alamu et al., 2007a). In comparison to petroleum-based fuels, biodiesel offe- red reduced exhaust emissions, improved biodegrada- bility, reduced toxicity and higher cetane rating which can *Corresponding author. E-mail: tolasum@yahoo.com. improve performance and clean up emissions. Typical biodiesel produces about 65% less net carbon monoxide, 78% less carbon dioxide, 90% less sulphur dioxide and 50% less unburnt hydrocarbon emission (Margaroni, 1998; Ryan et al., 1982; Knothe and Steidley, 2005; Krahl et al., 2006). The search for renewable energy resources continues to attract attention in recent times. It has been reported that in diesel engines, vegetable oils can be used directly as fuel, or as blend with petroleum diesel (Gupta et al., 2007; Math, 2007). However, due to high viscosity of these oils, poor fuel atomization occurs in CI engines resulting in improper fuel-air mixture and inefficient combustion (Bari et al., 2002; Saravanan et al., 2007). The problem also manifests in injector coking, engine deposits and thickening of lubricants during extended operation of the engine (Ryan et al., 1982; Alamu et al., 2007a). The high viscosities of vegetable oils are how- ever reduced through the process of transesterification. Satisfactory results have appeared in the literature on production of biodiesel through transesterification of different kinds of vegetable oil from different parts of the world. Such feedstock include soybean (US), rapeseed (Europe), oil palm (South-East Asia), jatropha curcus and rice bran oil (India). Biodiesel from canola, waste restau-