Production de biocarburant (biodiesel) à partir des huiles des microalgues et des macroalgues

Abstract

Most of the energy consumed in the world comes from oil. However, this source is limited and could be exhausted by the end of the next century. For these reasons, it is necessary to replace fossil fuels with alternative energy sources such as biofuels. This work is part of this global approach to synthesize biofuel and more particularly biodiesel from macroalgae oil and microalgae. Our work focused on four algae, three macroalgae (Ulva lactuca, Sphaerococcus coronopifolius and Cystoseira amentacea) and one microalgae (Nannochloropsis gaditana). The "Soxhlet" lipid extraction method was used to determine the lipid content of these microalgae. In order to produce biodiesel from algal biomass, a transesterification reaction was performed. The results obtained show that the lipid content in Ulva lactuca, Sphaerococcus coronopifolius, Cystoseira amentacea and the microalga Nannochloropsis gaditana is 10.41%, 14%, 15.16% and 18.33% respectively. The yield of biodiesel produced by the direct transesterification reaction is higher in the microalgae Nannochloropsis gaditana (39.7%) compared to macroalgae. Indeed, the biodiesel content in Ulva lactuca, Sphaerococcus coronopifolius and Cystoseira amentacea is 31.2%, 35.3% and 35.1%, respectively. The comparison between biodiesel yield in macroalgae species and a microalgae species clearly shows that microalgae are a better candidate for future biodiesel production.