Biodiesel production by transesterification of recycled vegetable oils

Abstract

Biofuels constitute an effective alternative to existing fossil fuels, for they offer the prospect of ecological sustainability with their various advantages. Biodiesel has become one of the most important biofuels on a worldwide level; and it is synthesized by oil transesterification. In this study, the production of biodiesel is done by oil transesterification. Two types of oil are used: the first is the regular ELIO oil (edible vegetable oil composed of 20% of sunflower and 80% of soybean); the second type is the recycled oil used at most three times for frying. Some parameters characterizing these oils are determined as follows: the refractive index, the cetane number, the acid number, and the saponification number, in addition to the evaluation of density and viscosity variations at different temperatures. The characterization of the obtained products can be summarized in the determination of the acid number and the flashpoint, through the study of density and viscosity variations at different temperatures, and by infrared spectroscopy. The latter shows us that the formed biodiesels are indeed methyl esters of fatty acids. A comparison between these two types of synthesized biodiesels and the international standards has shown that the synthesized biodiesels are in conformity with the international standards.