Síntese de biodiesel a partir do sebo bovino

Abstract

Nowadays the demand for sustainable energy is growing. This increase leads the search for new energy sources, as the biodiesel is. It has animal or vegetable origin. Currently the beef tallow – from animal origin – is taken as a residue that cannot be discarded in the environment. It is a raw material already used in the biodiesel production. However it has high levels of free fatty acids (FFA), what makes its production harder. Therefore pre-treatments are needed in order to reduce these levels. In this study the pre-esterification of the beef tallow and its following transesterification are evaluated. Firstly the methyl esterification with sulfuric acid catalyst is done. It was valuated trough a 2² planning, ranging the molar ratio oil/methanol in 1:9 and 1:12, and also the acid content in 1% and 1,5%, keeping the reaction temperature at 60 ºC for one hour. To proceed with the biodiesel production it was utilized the most efficient of them. For the transesterification was also followed a 22 planning using basic homogenous catalysis, with NaOH and KOH as catalysts and oil/methanol molar ratio 1:9, ranging the catalysts amount of 0,5% and 1%. The reactions periods were 30 and 45 minutes under 60 ºC. The goal is to produce a good quality biodiesel with a good yield after the raw material esterification. For the sodium hydroxide biodiesel there was synthesis of soap for the experiments 3 and 4, a 22% yield for the 1 and 2. Working with the potassium hydroxide biodiesel a yield of approximately 52% was obtained. It can be concluded that the catalyst content is fundamental in the reaction, nevertheless the reaction time did not influence the yield relevantly. It was observed that the more efficient catalyst was KOH.