Esterificação de ácidos graxos em sistemas heterogêneos SO42-/La2O3/HZSM-5: efeito do teor de La2O3 na atividade catalítica

Abstract

The esterification reaction has a great importance in the industrial process and is also possible to get biodiesel through it. Biodiesel has been pointed as a promissing biofuel with a big potential due to its ability to reduce emissions of gases and because can be used in a sustainable way. Based on this perspective were produced catalysts based on sulfate lanthanum oxide which may vary the quantity from 2 to 20% weight and HZM-5 zeolite. We evaluated the influence the amount of sulfate lanthanum oxide supported by the HZSM-5 in the conversion of its reaction of oleic acid esterification in a methyl medium for producing methyl oleate. The materials produced were characterized by TGA/DTA, X-ray diffraction (XRD), adsorption/desorption of N2 and infrared spectroscopy (FTIR) in the structural region. In general, was observed that the changes were not able to destroy the original structure of the zeolite in any of the catalysts. Also evaluated the influence of the amount of catalysts added to the reaction (2; 5 and 10% with respect to weight of oleic acid) and the influence of molar ratios (1:10, 1:20 and 1:45). We obtained converting the most significant results for the molar ratio (oleic acid/methanol) of 1:10 and 5% of catalyst. The catalyst with the highest efficiency that was modified with 10% La2O3 (HZ/OLS/10%), which generated the maximum conversion. In general, the catalysts were effective, we observed that the most of the changes were effective and produced much more active catalysts than the starting material.