Produção de biodiesel empregando catalisadores nanoestruturados do tipo SBA-15 modificada com lantânio

Abstract

The dissertation proposal to study the application of mesoporous silica SBA-15 modified with lanthanum as a heterogeneous catalyst in the esterification and transesterification reactions for biodiesel production. The catalyst lanthanum-incorporated SBA-15, La-SBA-15, with different Si/La molar ratios (75, 50, 25) were synthesized. The heterogeneous catalyst La- SBA-15 has acid characteristics which can be more tolerant of water and free fatty acids present in oils and can simultaneously catalyze the esterification and transesterification reactions. The catalyst was characterized by XRD, SEM and nitrogen isotherms at 77 K analysis. For study the application of La-SBA-15 catalyst in the transesterification reaction was used as feedstock the soybean oil and esterification reaction the oleic acid. Before the reaction, both raw materials were characterized as the fatty acid composition by gas chromatography, acid value, iodine value, saponification index, density, kinematic viscosity and water content. First applied the catalyst La-SBA-15 with different Si/La molar ratios in the esterification reaction of oleic acid with ethanol, verifying that the catalyst with Si/La = 50 molar ratio showed the highest catalytic activity in the reaction with conversion of 91,14%. Therefore, the La-SBA-15 catalyst with Si/La molar ratio of 50 was the best ratio for use of SBA-15 modified with lanthanum as a catalyst. Then used the La-SBA-15 catalyst with Si/La molar ratio of 50 in the transesterification reaction of soybean oil with ethanol resulting in conversion of 80.00%. So observed that the La-SBA-15 catalyst with Si/La molar ratio of 50 can catalyze both esterification and transesterification reactions.