Avaliação da reação de interesterificação do óleo de soja degomado e acetato de metila catalisada por fosfato de nióbio

Abstract

Biodiesel is considered the cleanest and most viable fuel in the world, an alternative to petroleum, which is less polluting and does not contribute to the increase in carbon dioxide emissions. The incessant search for new routes and raw materials for a more efficient and sustainable production encouraged this study, which aimed to investigate the interesterification reaction for the production of biodiesel from degummed soybean oil (DSO) in methyl acetate (MeA) in a batch process with niobium phosphate (NbOPO4) as a catalyst. DSO was characterized and showed low acidity (2.17 wt%), low water content (0.14 wt%) and a convertibility of 69.29 ± 3,62 wt%. The catalyst was also characterized and proved to be active in the experimental conditions investigated. NbOPO4 has an amorphous structure with a large specific area. The effects of temperature, catalyst concentration and DSO: MeA molar ratio were investigated through an experimental design rotational central composite type (RCCD) in two different reaction times. All variables were significant for the process. From the kinetic study, the highest FAME content was 60.61% representing in terms of yield 87.47 wt%, obtained at 345 °C, 8 wt% catalyst concentration and molar ratio OSD: MeA of 1:35 in 60 min of reaction. Some reaction conditions were used in the decomposition analysis, in all studied reaction conditions there is decomposition of fatty components mainly due to OSD exposure to large catalyst concentrations, high temperatures and long reaction periods. Finally, the catalyst reuse test pointed to a 34,59 wt% decrease in activity, which may be related to the adsorption of contaminants, in addition to the loss of mass.