Assessment of niobium phosphate as heterogeneous catalyst in esterification with methyl acetate

Abstract

BACKGROUND The aim of this work was to investigate the esterification reaction from oleic acid with methyl acetate (MeA) catalyzed by niobium phosphate to produce methyl esters. This catalyst has an amorphous structure and large surface area. Catalytic tests were performed according to an experimental design. The results were analyzed statistically and all of the variables were significant, especially the temperature. RESULTS A kinetic study of the reaction was carried out and the most suitable reaction conditions were 240 °C, 10% (m/m) of catalyst and MeA: oleic acid molar ratio 10:1. After 2 h, it was possible to obtain ≈80% (m/m) methyl oleate content. A noncatalytic test corroborated niobium phosphate activity in the reaction. A kinetic model fitted experimental data for the catalyzed and noncatalyzed reactions; kinetics parameters for Arrhenius equation were estimated. In a reuse test, the catalyst showed a gradual decrease in catalytic activity over five reaction cycles. CONCLUSION Niobium phosphate can be considered as a promising heterogeneous catalyst for biodiesel synthesis. © 2019 Society of Chemical Industry

Kinetic and Nonideal VLE Modeling for Transesterification Reactions from FFA and Methyl Acetate at High Temperature and Pressure Considering Volatilization Effects/Influence

“…Niobium phosphate was gently donated by the Brazilian Company of Metallurgy and Mining (CBMM, Brazil). The solid catalyst was milled and sieved to reduce the average particle size to 300 μm and calcined at 300 °C at a heating rate of 10 °C min −1 for 2 h. Niobium phosphate characterization can be found in Alves et al 18 for the same lot received from CBMM.…”

“…For esterification from FFA and alcohols, the kinetic reaction without a mass transfer rate and VLE considerations has been extensively studied and modeled for several combinations using heterogeneous catalysts 19−21 and at subcritical conditions. 22,23 For the FAME production reaction from FFA and esters like methyl acetate, the transesterification reaction, there are still a few kinetic studies available in the literature, 18,24 and the existing ones also disregard the influences of mass transfer rate and VLE.…”

“…17,18,24 Alves et al 18 and Ketzer and de Castilhos 24 proposed kinetic studies and modeling of a batch transesterification reaction from oleic acid and methyl acetate using heterogeneous catalysts ranging the molar ratio, catalyst concentration, and temperatures below the mixture critical point. However, this kinetic modeling approach 18,24 did not include in their experimental design, variables that demonstrate the influence of compounds' volatilization in the chemical equilibrium and kinetic rate. Thus, these models were not able to predict variations in FAME yields due to compound volatilization, mainly as observed in transesterification experiments from FFA with different values of initial reaction volume.…”

Biodiesel at the Crossroads: A Critical Review

“…These studies manifested that the reaction conditions to obtain Gliperol are similar to that for the production of Biodiesel. Likewise, this reaction has been studied over heterogeneous acid catalysts [68][69][70][71][72][73][74][75][76][77][78][79] as well as using lipases as biocatalysts, either in solvent-free systems [80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95][96][97] or in ionic liquids [98][99][100][101]. Furthermore, many other innovative technologies have also been applied, such as supercritical conditions [102][103][104][105][106][107][108][109][110][111][112][113][114][115]…”

Synthesis of glycerol‐free fatty acid methyl ester using interesterification reaction based on solid acid carbon catalyst derived from low‐cost biomass wastes

“…10 Heterogeneous acid catalysis in glycerol-free methyl acetate-assisted interesterification had not been thoroughly investigated by any researchers to the best of the authors' knowledge. Ketzer et al 4 applied tungsten oxide-activated USY zeolite in the interesterification of oleic acid, whereas Alves et al 11 studied the same process using niobium phosphate. Alessio et al 12 had also employed niobium phosphate in the biodiesel synthesis between oleic acid and dimethyl carbonate.…”