Abstract:
In this work, Moringa stenopetala seed oil is evaluated for the first time as potential feedstock
for Biodiesel. Transesterification of M.stenopetala seeds oil was carried out with methanol,
ethanol and mixture of methanol & ethanol (ME) in 3:3 molar ratios and using KOH as a
catalyst. The esters were characterized by various methods to evaluate their densities,
viscosities, water & ash content, iodine values, acid numbers, cloud & pour points, gross heat
of combustion and fatty acid composition to use it in diesel engines. The experimental results
show that M.stenopetala seeds contain 45% of oil. The oil was found to contain high level of
mono-unsaturated fatty acids (78%), while the saturated fatty acid amount to 22%. The
dominant fatty acid is oleic (76%). When methanol and ethanol used in 3:3 molar ratio (ME),
the amount of ethyl ester formed was 30% that of methyl ester. The most conspicuous
property of biodiesels derived from M. stenopetala oil is the low kinematic viscosity of
3mm2/s for mixed ester (ME) and 3.2mm2/s for methyl ester at 40oC, which is among the
lowest reported for a biodiesel fuel. The physicochemical properties of mixed ester ME (3:3)
was better than that of pure M.stenopetala methyl ester. Therefore, the best choice to use as a
fuel would be the mixture of Moringa ester (ME). Their blending with conventional diesel
(B20) also studied. All of the determined physicochemical properties of M.stenopetala oil
methyl ester and mixture of ester were found to comply with both the American ASTM
D6751 and the European standard EN 14214. Biodiesel derived from M.stenopetala oils is an
acceptable substitute for petrodiesel when compared to biodiesel fuels from other vegetable
oils. Therefore, the major physicochemical properties of M.stenopetala seed oil make it an
attractive alternative application to the existing feedstocks for biodiesel production in
Ethiopia.
Key words: M.stenopetala seed oil, Biodiesel, Transesterification, Methyl ester, Mixture of
ester, Fuel properties, Blend.