Síntese por reação de combustão de catalisadores à base de óxidos ferrosos dopados com alumínio para a produção de biodiesel.

Abstract

Global warming and other environmental problems have raised concerns and the interest for the development of clean and renewable fuels. Within the context, biodiesel has been extensively studied, new routes, used catalysts, raw materials, processes etc. The development of heterogeneous catalytic systems for biodiesel production has been worldwide interest for innumerable factors such as environmental, economic and etc., however, the conversion heterogeneous systems are inferior to homogeneous systems. Thus, in the present work, catalysts based on ferrous oxide of the Fe2-xAlxO3 type were synthesized by combustion with aluminum for the production of biodiesel the by the processes of transesterification, esterification and inter-esterification. The catalysts were characterized by X-ray diffraction, particle size analysis, textural analysis, scanning electron microscopy, Xray fluorescence spectroscopy by dispersive energy, carbon content, thermogravimetric analysis and magnetic property analysis. The catalysts were subjected to transesterification and interesterification reactions of soybean oil and esterification of oleic acid with variation of the molar ratio. The synthesis by combustion reaction was monitored with the time and temperature reached. The reaction by combustion was effective non-reagent consumption, showing reproducibility, practicability and a fast method to synthesize nanostructured magnetic catalysts with the possibility of production of the powder at industrial scale. The catalysts were effective in the transesterification, reaching a conversion of up to 96% in methyl esters (biodiesel). In the interesterification reactions with methyl acetate it reached conversions of up to 92% in biodiesel with the differential of being a reaction free of formation of glycerin. In the esterification process using mild reaction ranges as the highest conversions were 78%. Thus, the catalysts based on ferrous oxides doped with a concentration of 1 and 1.5 moles of Al+3 presented great potential of industrial production in the production of biodiesel.