A new kinetic model for simultaneous interesterification and esterification reactions from methyl acetate and highly acidic oil

• Published in: Renewable energy 2020-08, Vol.156, p.579-590
• Main Authors: Brondani, L.N., Ribeiro, J.S., Castilhos, F.
• Format: Article
• Language: English
• Subjects: Alumina; Biodiesel; Catalyst; Macaw pulp oil; Triacetin
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2020.04.063

This work presents the development of a kinetic model for simultaneous reactions of esterification and interesterification from macaw oil and methyl acetate using γ-alumina as the heterogeneous catalyst. Experimental data varied between 225 °C and 300 °C, catalyst concentration of 2 wt%, 5 wt%, and 10 wt% and molar ratio (methyl acetate: Oil) of 10:1, 20:1 and 40:1. Arrhenius kinetic parameters were concomitantly estimated for all experimental conditions by minimizing the objective using a hybrid optimization algorithm. From the results, it could be verified that γ-alumina is an active catalyst for both interesterification and esterification reactions with MeA and a high acid glyceride source. The simultaneous reaction system indicated an endothermic character at experimental conditions investigated. The FAME conversions presented a strong limitation of chemical equilibrium. Moreover, it could be verified that the esterification reaction produces about 80% of total fatty acid methyl esters and that acetic acid played the main role as a reagent through reactions with glycerine acetates and not as a catalyst. The proposed kinetic model satisfactorily fitted the experimental results. •New kinetic model was proposed for interesterification and esterification reactions.•Reactions were carried out from macaw oil, a highly acidic oil, and methyl acetate.•Kinetic parameters were concomitantly estimated in different reaction conditions.•The model fitted the experimental results well and was validated.•Simulated data from the model showed that acetic acid played a reagent role.