Optimisation of experimental conditions for biodiesel production from alkali-catalysed transesterification of Jatropha curcus oil

India is looking at renewable alternative fuel sources to reduce its dependence on foreign oil. As India imports 70 % of the oil it uses, the country has been hit hard by increasing costs and uncertainty. Biodiesel fuel derived by the transesterification of non-edible oil from Jatropha curcus meets the requirements of a diesel fuel. Further, its cultivation and use do not add to net global warming. In the present study, different variations of methanol (10, 15, 20 and 25 %), sodium hydroxide (0.5, 1.0 and 1.5 %), reaction time (30, 60, 90 and 120 min) and reaction temperature (30, 45 and 60$dGC) were adopted in order to optimize the experimental conditions for maximum ester (biodiesel) yield from alkali-catalysed transesterification of Jatropha curcus oil. The preliminary studies recorded that the methyl ester yield varied widely in the range of 30 to 98 % in the laboratory-scale biodiesel reactor. The average biodiesel yield of 96 % was obtained in a large-scale study conducted in the Tamil Nadu Agricultural University (TNAU) biodiesel pilot plant. The fuel properties of biodiesel, namely kinematic viscosity and specific gravity, were found to be within the limits of Bureau of Indian Standards (BIS) specifications for diesel fuel. Among the chemical properties, free fatty acids and acid value were determined to be 3.095 % and 6.16 mg of KOH/g of sample in raw oil and these properties for biodiesel were found to be within the specified limits.