Molecular sieves have been applied to the triacylglycerides processing in the production of biodiesel through transesterification reaction. The purpose of obtain a material that has characteristics favorable to higher biodiesel conversion, this paper aims to synthesize molecular sieves SBA-15 and Al-SBA-15 on two reasons Si/Al (Si/Al= 10 and 100) evaluated in the transesterification reaction of soybean oil and investigate the potential of Si/Al ratios in the reaction over the acid each material. The catalysts were prepared by conventional hydrothermal method by varying the composition of the aluminum consequently altering the acidity of the material, since this reaction takes place in acid medium. The samples were characterized by X-Ray Diffraction (XRD), scanning electron microscopy (SEM), Spectroscopy in the infrared region by Fourier transform (FTIR). The results of the characterization of the catalysts have shown that the materials were successfully obtained, from the characterization observed. The biodiesel syntheses were conducted with soybean oil using ethyl alcohol 12: 1 relative to the oil and 5% of catalyst in the reactor with autogenous pressure. Were realized viscosity analyzes as conversion parameter of the vegetable oil into biodiesel. From the results of biodiesel viscosity was obtained a yield of 13% on average by using the Al-SBA-15. However, even not have remained within the specifications the standards of the National Petroleum, Natural Gas and Biofuels, catalysts showed efficiency compared with the SBA-15 in biodiesel synthesis.

The world's energy production is generated mainly from fossil fuels, so it is important to develop fuels from renewable sources. Growing caution with the environmental impact imposes restrictions on emissions from the combustion of fossil fuels. With increasing human population and expanding economies in both developing and developed countries, there is an increase in energy consumption and production. The need arises to supply this high energy production with a renewable and reliable source fuel [1]. These facts have stimulated research by alternative sources for the development of renewable fuels. One of the most promising fuels is biodiesel, an alternative to petroleum diesel from high-quality renewable sources, which allows the replacement of fossil diesel oil without modifications to the vehicle's engine [2, 3]. In recent years, methyl esters of fatty acids derived from vegetable oil have gained considerable attention as alternative fuel [4, 5].

The present study describes the preparation of catalyst MoO3 supported on smectite clay by the solution impregnation method and its evaluation as a heterogeneous catalyst in the production of biodiesel from soybean oil. The individual effects of catalyst (hard green clay and MoO3/hard green clay) on kinematic viscosity of produced biodiesel and conversion were investigated. The samples were characterized by X-ray diffraction, X-ray fluorescence spectroscopy and N2 adsorption-desorption. Conditions of soybean oil transesterification were: 5% catalyst by weight, 1:12 oil to methanol molar ratio, at 200 oC for 60 minutes. Patterns of X-ray diffraction showed the characteristic peaks of the structure of smectite. The results of X-ray diffraction suggests that MoO3 species exist as highly dispersed surface species. Molybdenum metal identified as effective catalysts for the transesterification reaction of soybean oil with methanol. A preliminary design assessment show that this catalysts (MoO3/HGC) is sufficiently active achieving conversion in excess of 62,07% at temperature below 200 oC.