A catalyst comprised of SnO2 impregnated on ZnO nanowires, which presented remarkable ability to catalyze fatty acid esterification/transesterification reactions, is reported. For optimization of reaction conditions, artificially acidified soybean oil with 10 wt.% oleic acid was used as a model feed. The optimized conditions were: 150 °C, 6 h, 5 g of oil, catalyst concentration of 5%, and methanol:oil molar ratio of 15:1. The catalyst achieved 92% of total fatty acid methyl esters (FAME) content and was used five times without the necessity of catalyst washing from one reaction to the other. Then, such conditions were applied to produce biodiesel from the oil extracted from Scenedesmus sp. microalgae; the system reached 72% of FAME content, without any previous refining or degumming process of the oil. Rietveld refinement, X-ray diffraction, elemental mapping in scanning transmission electron microscopy, X-ray photoelectron spectroscopy, and pyridine-desorption Fourier-transform infrared spectroscopy were used to characterize the material.

It is presented herein heterogeneous catalysts comprised of strontium and nickel oxides synthesized using a coprecipitation method. They were applied for the preparation of biodiesel from macaw palm oil. The catalysts were characterized by X-ray diffraction (XRD), adsorption and desorption of nitrogen by Brunauer-Emmett-Teller (BET) and Barrett-Joyner-Halenda (BJH) methods, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and differential thermogravimetric analysis (TG-DTA). The conversion was determined by gas chromatography with flame detector (GC-FID). The best activity was obtained when the catalyst was calcined at 1100 °C for 3 hours. The highest conversion was reached (97%) when the following conditions were used: 5 hours, 2% of metal loading, 65 °C and oil/alcohol molar ratio of 1:9.

Este trabalho descreve a preparação de biodiesel proveniente de óleo de babaçu, mamona e misturas destes em várias proporções, utilizando compostos alcalinos de estrôncio (SrO + SrCO3 + Sr(OH)2) como catalisadores heterogêneos. A mistura de óleos dessas oleaginosas foi utilizada na produção de biodiesel com parâmetros de qualidade que atendam a legislação vigente. O catalisador foi caracterizado por difratometria de raios X (XRD), fisissorção de gas (método BET), microscopia eletrônica de varredura (SEM), espectroscopia de raios X por dispersão em energia (EDX) e espectroscopia no infravermelho com transformada de Fourier (FTIR). Os parâmetros reacionais foram acompanhados através da viscosidade dos biodieseis obtidos. As reações de transesterificação usando os compostos de estrôncio apresentaram taxas de conversões de 97,2% (óleo de babaçu), 96,4% (óleo de mamona) e 95,3% (mistura de óleo de babaçu com óleo manona na proporção de 4:1).

This work describes the preparation of babassu, castor oil biodiesel and mixtures in various proportions of these oils, using alkaline compounds of strontium (SrCO3 + SrO + Sr (OH)2) as heterogeneous catalysts. The mixture of oils of these oleaginous sources was used in the production of biodiesel with quality parameters that meet current legislation. The catalyst was characterized by X-ray diffractometry (XDR), physisorption of gas (BET method), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR). The viscometric technique was used to monitor the optimization. The transesterification reactions performed using strontium compounds reached conversion rates of 97.2% babassu biodiesel (BB), 96.4% castor oil biodiesel (COB) and 95.3% Babassu/Castor Oil Biodiesel 4:1 (BBCO41).