Produção de hidrocarbonetos renováveis a partir da desoxigenação catalítica do óleo de macaúba (Acrocomia aculeata) utilizando os materiais mesoporosos AlSBA-15 E Mo/AlSBA-15

Abstract

The demand for renewable energy resources has led to an increase in the search for biofuels obtained from vegetable oils. On that subject, vegetable oils that are not used for alimentation, such as macauba oil, are promising. In order to obtain renewable hydrocarbons from macauba, catalytic pyrolysis can be used to promote oil deoxygenation. Thus, in the present work, AlSBA-15 synthesis and its subsequent impregnation with molybdenum were performed aiming at the catalytic deoxygenation of macauba oil. Pure and esterified macauba oils were characterized by acidity index, density, viscosity, thermogravimetry (TGA) and differential scanning calorimetry (DSC), showing results similar to those found in the literature. Catalyst characterization was carried out by thermogravimetry (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled to energy dispersive X-ray analysis (EDAX) and Fourier transform infrared spectroscopy (FTIR). The catalysts showed reflections in the X-ray diffraction, which is a characteristic of the highly ordered hexagonal P6mm structure of the mesoporous material SBA-15, showing that the metal incorporation did not damage the molecular sieve structure. Infrared spectrum showed bands that are characteristic of SBA-15 type materials, such as 1088 cm-1, 804 cm-1, and 467 cm-1 bands, which refer, respectively, to asymmetric and symmetric stretching vibration and the Si-O-Si bond deformation, present in the structure of SBA-15. Additionally, it was observed the presence of a 964 cm-1 band associated with the stretching of the Si-OH bond of the silanols groups that compose the structure of the mesoporous material. Analysis of thermogravimetry coupled to Fourier transform infrared spectroscopy was carried out, allowing that the products obtained from the decomposition/volatization of macauba oil by FTIR were evaluated. The samples with the catalysts also had the products of their decompositions evaluated by FTIR. The results obtained by TGA-FTIR for the samples with catalysts showed bands in the range of 2400-2250, referring to the C=O bond of the CO2 group, which led to the conclusion that AlSBA-15, and especially Mo/AlSBA-15 catalysts, caused the deoxygenation of macauba oil with the consequent production of hydrocarbons.