Kinetic study of the conversion of glucose to 5-hydroxymethylfurfural using niobium phosphate

Abstract

The present study seeks to propose a robust reaction network to determine the kinetic parameters of the glucose to HMF conversion reaction, via fructose as intermediary, in aqueous medium using niobium phosphate (PNb). The catalytic activity of PNb was evaluated in a reaction mixture consisting of a 2% (m/m) glucose solution, glucose/PNb ratio of 3:1, between temperatures 125 °C and 145 °C, for 180 min. The selectivity for HMF reaches a maximum of 80.4 ± 0.2% at 125 °C for 15 min. The catalyst was characterized before and after catalytic tests, leaching and reuse. The Holfield neural network model was used to estimate the kinetic parameters based on a system of differential equations obtained by the mathematical modeling of the proposed reaction network. The agreement between the concentration values of the compounds predicted by the model with the experimental results was satisfactory.