Obtención de biodiesel por transesterificación de aceites vegetalesNuevos métodos de síntesis

Abstract

Biodiesel is one of the alternatives to the use of hydrocarbons and fossil fuels. During the research phase it were developed the following sections: - Transesterification with potassium impregnated in calcium oxide. It has been observed that the impregnation increases the basicity of the catalyst. However it wasn�t possible to reuse the catalyst. - Transesterification in -sub-critical conditions, from rapeseed oil using methanol in sub-critical conditions. It has been possible to obtain a high yield (99.9%) at a relatively low reaction pressure. - Transesterification with co-solvents, from rapeseed oil using methanol and different co-solvents. The presence of co-solvent facilitates the reaction of transesterification, yielding a conversion of 97.6% using di-ethyl ether, at a temperature of 30 °C. - Transesterification using an ultrasonic bath, from castor oil using methanol as catalyst. High conversions were obtained, at relatively low reaction temperatures. - Transesterification using an ultrasonic processor, from rapeseed oil using methanol as catalyst. The ultrasonic irradiation facilitated the transesterification yielding high conversions to biodiesel in small reaction times (20 minutes). It was studied, in each section, the influence of different variables on the process of transesterification. It was developed a simple economic study of the process of biodiesel production in sub-critical conditions. It was verified that the highest percentage of total production cost of biodiesel is related to the raw material. It was undertaken a study of the characterization of wastewater produced in the purification step of biodiesel, for further study of treatment and possible reuse in biodiesel synthesis process.