Ethyl ester biodiesel has been produced from a non-edible Jatropha curcas oil. Oil was extracted from the plant seed using n-hexane at 60˚C and pretreated by alkaline refining process to reduce the free fatty acid level to less than 1%. Base-catalysed transesterification reaction with absolute ethanol using potassium hydroxide catalyst was adopted for the conversion. Various physicochemical properties of the refined Jatropha curcas oil were investigated. The ethyl ester biodiesel produced was characterised for its fuel properties such as specific gravity at 15˚C, flash point, pour point, kinematic viscosity, cetane number, iodine value and higher heating value using American Society for Testing and Materials Standard Methods. The crude and refined Jatropha curcas oil yields were 58.16% and 52.5%. The physicochemical analysis revealed FFA, saponification value and peroxide value of refined Jatropha curcas oil to be 0.58 mg KOH/g, 159.9 and 1.92 m E/kg respectively. The fatty acid composition obtained from gas chromatography (GC) revealed that the oil contained 44.85% oleic acid as the dominant fatty acid, while Margaric 0.01% and Behenic 0.02% the least. The biodiesel yield was 57.6%, and its measured fuel properties conformed with ASTM 6751 and EN 14214 standards.

This work focuses on production of biodiesel from natural and refined castor seed oil. Oil was extracted with normal-hexane solvent at 60°C using Soxhlet apparatus and pretreated by alkaline refining process before transesterification with methanolic potassium hydroxide solution as catalyst. The effect of alkaline refining on the oil characteristics and biodiesel quality parameters was investigated using standard test methods and fatty acid methyl ester was characterized using gas chromatography. Results revealed that alkaline refining had significant improvement on the oil and biodiesel characteristics. Yield of 43.9 and 46.2% were obtained for refined and unrefined castor oil respectively while biodiesel yield from refined and unrefined castor oil was 43.5 and 41.7% respectively. Ricinoleic acid (84.9%) was prevalent in the oil with lignoceric (0.03%) as the smallest. The conformity of refined castor oil biodiesel with EN 14214, ASTM and India biodiesel standards makes it viable economically in Nigeria.