Ésteres etílicos de microalga

Abstract

The biomass of microalgae has been attracting great scientific interest as raw material for biodiesel (fatty acid esters), due to the high oil content of some species, and its importance for biocompounds production. Its great advantage with respect to traditional raw materials (oil) is centered on the fact that the microalgae cultivation does not compete with the food production, especially regarding the production of biofuels, and aids in the capture of CO2, having a beneficial impact to the environment. Given this promising potential, this work aims to investigate the production of ethyl esters from microalgae oil, evaluating the physical properties of these esters and oil, as well as studying liquid-liquid equilibrium of mixtures of interest.For this purpose, commercial microalgae oil of the species Chlorella protothecoides, obtained from Soleybio company, was used as raw material for biodiesel production and ethanol as reagent alcohol, giving to this biofuel a completely renewable character. The oil was characterized in terms of their fatty acids and its composition in triglycerides (TAG) was estimated. The viscosity and density temperature dependence, acidity number and moisture content were determined for oil and its respective biodiesel. Analysis of flash point has been made exclusively for biodiesel. Finally, the study of the liquid -liquid equilibrium of mixtures biodiesel + glycerol + ethanol and microalgae biodiesel + ethanol + oil was performed at 25, 40 and 55 °C. These systems are important in various stages of transesterification reaction and in the steps of biodiesel purification. The HPSEC technique was used to quantify the components at equilibrium phases and the equilibrium modeling was performed using the NRTL and UNIQUAC models. All the systems studied in this work presented balance deviations lower than 0.5%, indicating a good quality of the experimental data and the technique used. The great similarity between the properties of microalgae oil and biodiesel with respect to conventional oils and biodiesels indicate a high potential of microalgae as alternative raw material for the production of biofuels.