Study of Nanoferrites Ni0,5Zn0,5Fe2O4 and Ni0,1Cu0,4Zn0,5Fe2O4 as Catalysts in the Methyl Transesterification of Soybean Oil

Abstract

Research with emphasis on substitution of energy sources used in worldwide for renewable energy undoubtedly indicates that the use of biodiesel would be an option to increase the income in rural areas, reduction in oil derivatives spending and also new opportunities for job creation. Soon, in purpose to contribute with the research growth, this research proposes to evaluate the new catalysts performance as nanoferrites Ni0,5Zn0,5Fe2O4 (pure) and Ni0,1Cu0,4Zn0,5Fe2O4 (doped with 0.4 mol of Cu2+) in transesterification reactions of soybean oil methyl. For both samples were synthesized by chemical method in the stoichiometry of the combustion reaction, using urea as a fuel source and a resistance heating coil. During synthesis were measured time and combustion temperature. Later they were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), textural analysis (BET) and subjected to catalytic tests bench. The reaction conditions used in the transesterification were: 10 g of oil, 2 h reaction time, molar ratio of 1:20 oil and alcohol, 4% (w/w) of catalyst and reaction temperature of 160°C. Finally, the reaction product was characterized for conversion into methyl esters by gas chromatography. Results has shown only the presence of the inverse spinel phase, characteristic of Ni-Zn ferrite for both samples, with crystallite size of 26 and 29 nm, respectively. The thermogravimetric analysis has shown that samples are thermally stable, with a weight loss of 4.9 and 3.7%, respectively. The surface area and particle size were 48.89 m2g-1 and 23 nm, and 18.06 m2g-1 and 62 nm, respectively. The conversion results obtained by the transesterification reaction were 13 and 50% Ni0,5Zn0,5Fe2O4 and Ni0,1Cu0,4Zn0,5Fe2O4, respectively, indicating that sample with presence of copper was 26% more effectively, thus being one promising catalyst for the transesterification reaction, which aims to obtain biodiesel.