Evaluación cuantitativa de la producción de biodiesel de microalgas de lagunas de tratamiento de agua residual

Abstract

The decreasingof fossil fuel reserves and the environmental impact of carbon dioxide emissions, has encouraged the search for environmentally friendly and renewable fuel sources. Microalgae has been regarded, in this sense, as a promising renewable fuel source for the future. In this research, five different families of microalgae were cultured: Chorella, Scenedesmus, and three isolated but unidentified families. Lipid extraction of the algae biomass was performed using soxhlet extraction method, using six solvents which cover a wide range of polarities and solubilities. The extraction methodology implied the use of single solvents andsome selected binary solvent mixtures. The analysis showed that the binary solvent mixtures: methanol:hexane (1:3) and chloroform:methanol (1:2) were the most efficient in the extraction of lipids, producing lipid contents above 13%. Chlorella family showedthe highestconcentration of lipids with an average of 20.37%, followed by the Scenedesmus family with an average of 20.10%. A thermal pretreatment of cell disruption (autoclave) and physical disruption (lyophilization) were performed to the Chlorella microalgae and compared to undisrupted cells, showing no significant increase. Finally, the global productivity of the lipids were assesed by means of decreasing the nutrient availabitiy in the culture, showing an increase of the lipid concentration in the algae cells but a substantial decrease in the total lipid productivity. More research efforts are suggested in this regard.