Comparative Analysis of the Fuel Properties of Ethylester Biodiesels from Cyperus esculentus, Sesamum indicum and Colocynthus vulgaris Seed Oils

Abstract

The relative abundance of some Nigerian seed oils coupled with the little knowledge of their biodiesel usage prompted the need for this research. Biodiesel production is a very modern and technological area for researchers due to the relevance that it is winning everyday because of the increase in the petroleum price and the environmental advantages. In this work, studies were carried out to investigate the fuel properties of Cyperus esculentus, Colocynthus vulgaris, Sesamum indicum ethylesters and their corresponding ethyl ester blends. Ethylesters of these oils were prepared by H2SO4 catalysed transesterification reaction between the oils and ethanol. The fuel properties such as kinematic viscosity, flash points, pour point and water crackle were determined. GC-MS was used to determine the fatty acid profile of the transesterified oils. The fuel properties correlated very well with the fatty acid compositions. The results showed that the oils were rich in saturated fatty acids (66.67%), appreciable value of monounsaturated fatty acids (33.33%) and little percent (33.33%) polyunsaturated fatty acids and absence of polyunsaturated fatty acids in Cyperus esculentus and Sesamum indicum esters. The fatty acid chain lengths that were predominant in Cyperus esculentus, Colocynthus vulgaris, Sesamum indicum were C16, C18 and C20. The fuel properties of Colocynthus vulgaris, Cyperus esculentus and Sesamum indicum biodiesel blends were better when compared to the oil and petrodiesel in terms of flash points, viscosity and pour points, hence the optimum engine performance of both oil and petrodiesel could be improved by use of these biodiesel feedstock.