An assessment on kinetic modeling of esterification reaction from oleic acid and methyl acetate over USY zeolite

• Published in: Microporous and mesoporous materials 2021-02, Vol.314, p.110890, Article 110890
• Main Authors: Ketzer, Felipe, de Castilhos, Fernanda
• Format: Article
• Language: English
• Subjects: Eley-rideal; Langmuir-hinshelwood; Methyl oleate; Parameter estimation; Pseudo-homogenous
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2021.110890

In this work, commercial USY Zeolite was employed in oleic acid with methyl acetate esterification. Kinetic studies of esterification were carried out at methyl acetate to the oleic acid molar ratio of 10:1, with 5 wt% and 10 wt% of catalyst content and at 453, 473, 493 and 513 K. The Pseudo-homogeneous (PH) and Heterogeneous kinetic models, according to the Eley-Rideal (ER) and the Langmuir-Hinshelwood (LH) mechanisms, were investigated to correlate experimental data. The Thiele modulus analysis confirmed that the effect of the pore sizes on the internal mass transfer limitations could be neglected, and the study of the internal and external mass transfer limitations showed that the chemical reaction is the rate-controlling step. The coefficient of determination (R2), the Akaike's information criterion (AIC), the relative Akaike weight (λi), and Spearman's rank correlation coefficient (ρi,j) were utilized to evaluate the kinetic model's adequacy. The PH model provided the best results according to Akaike's information criterion (AIC) and relative Akaike weight (λi). Spearman's rank correlation coefficient (ρi,j) showed that some parameters of ER and LH models presented high correlation and confidence intervals in their parameters, not satisfactorily representing the observed kinetic data. The thermodynamic study through PH model shows that oleic acid with methyl acetate esterification is an endothermic (ΔH = 59.83 kJ mol−1) and endergonic (ΔG = 118.66–126.45 kJ mol−1) reaction. The activation energy (Ea) was 41.77 kJ mol−1, and the negative value of entropy variation (ΔS = −129.8 J mol−1 K−1) might be associated with its associative mechanism. The decrease of catalyzed activation energy compared to the uncatalyzed reaction indicates that the USY zeolite was active to the esterification of oleic acid with methyl acetate. [Display omitted] •USY zeolite was active in the esterification reaction with methyl acetate.•Three kinetic models were assessed and fitted well to experimental data.•Effect of pore sizes on the internal mass transfer limitations could be neglected.•Statistical criterion discriminated overparametrized models and unreliable parameters.•Pseudo-Homogeneous model was the most suitable.