One-step process to produce furfural from sugarcane bagasse over niobium-based solid acid catalysts in a water medium

Abstract

This study investigated the production of furfural from sugarcane bagasse over niobic acid (Nb2O2·nH2O, called as NbO) or niobium phosphate (NbOPO4·nH2O, called as NbP) in a one-step process performed in water. The variables temperature (T), the mass of catalyst (mcat), reaction time (rt), and vibration time (Vt) for mixing SCB and catalyst were studied through a design of experiments. After 5 h at 150 °C, the furfural yields were 52.1 g kg−1 for NbO and 59.3 g kg−1 for NbP, while the yields of xylose and arabinose were, respectively, 69.7 g kg−1 and 6.4 g kg−1 for NbO and 147.4 g kg−1 and 11.1 g kg−1 when using NbP. It was proved that furfural yield is independent of the SCB genotype. The selective depolymerization and hydrolysis of hemicellulose into monomers and its further dehydration to furfural were observed. The cellulose and lignin remained readily utilizable for further processing. The better catalytic performance of NbP was attributed to the higher ratio of Brønsted to Lewis acid sites on its surface than NbO.