Produção de biodiesel da gordura de murumuru (Astrocaryum murumuru) via catálise heterogênea

Abstract

This work investigated the feasibility of Murumuru oilseed (Astrocaryum murumuru) as raw material for biodiesel production through the use of heterogeneous catalysis in the basic transesterification. Murumuru is a fruit composed of pulp and kernel, producing about 50% of white fat, odorless, with the advantage of not be tasteless easily because it is rich in saturated fatty acids of short-chain such as for lauric and myristic. The biodiesel is conventionally production through the basic homogeneous catalysis. However this catalysis presents a few inconvenients, such as saponification of esters and the difficulty of removing the catalyst. On the otter hand, the heterogeneous catalytic route avoids the drawbacks of homogeneous catalysis, reducing the amount of aqueous effluent generated during the process and reuse of catalysts. The heterogeneous catalyst hydrotalcite, was synthesized and evidenced by analysis of X-ray fluorescence, X – ray diffraction, thermal analysis, textural analysis (BET method) and electronic scanning microscopy. A complete factorial planning was conducted using methanol as reacting product. Independent variables were temperature, molar ratio and catalyst concentration and the response variable was the conversion, measured through spectrophotometric method. These reactions were conducted in to a pressurized batch reactor. The best conversion found through factorial planning was 88,97% for molar ratio of methanol/oil worth 12, temperature of 200ºC and catalyst concentration equaling 6% in 1 hour of reaction. For this condition, kinetic studies were performed and tested the use of ethanol; through the kinetic study a good correlation can be achieved between the kinetic constants and conversion when using the model that considers reversible reaction, chemical reaction as controlling stage following the Eley Rideal mechanism.