Preparation, characterization and evaluation of x-MoO3/Al-SBA-15 catalysts for biodiesel production
Joyce Salviano Barros de Figueiredo, Bruno T. S. Alves, Vitória de Andrade Freire, José Jaílson Nicácio Alves, Bianca V. S. Barbosa
Abstract
Abstract Biodiesel is an alternative source of renewable energy that can be produced by a transesterification of vegetable oils. Mesoporous molecular sieves, such as SBA-15, due to high surface area and thermal stability are promising precursors for heterogeneous catalysts in the transesterification reaction. In this work, Al-SBA-15 precursor was obtained by direct hydrothermal synthesis, impregnated with different MoO 3 contents (5, 10 and 15 wt%) by the pore saturation method, and evaluated as heterogeneous catalyst in the production of biodiesel from a transesterification of soybean oil with methanol. Al-SBA-15 precursor as well as MoO 3 /Al-SBA-15 catalyst were characterized for its structural characteristic by X-ray diffraction, textural characteristic by N 2 adsorption analysis, and thermal stability by thermogravimetric analysis. An experimental planning 2 2 + 3 CtPt was used to evaluate the influence of MoO 3 content and reaction time on biodiesel yield from soybean oil and methanol. The biodiesel content in the final product was obtained by gas chromatography. An average biodiesel yield of 96% was obtained with the catalyst 10%MoO 3 /Al-SBA-15 under the following reaction conditions: 20:1 methanol/soybean oil molar ratio, and 3 wt% of catalyst loading at 150 °C in 3 h. After five consecutive reaction cycles, the biodiesel yield decreased by about 34%. The density and acidity of the biodiesel produced are within the specified values for commercialization according to international standards. Graphical abstract