Use and reuse of niobium phosphate catalyst for the removal of hemicellulose and production of furfural from raw bagasse, straw, and energy sugarcane

The production of bio-based furfural is well known, but processes that use homogeneous catalysis with mineral acids such as sulfuric acid are environmentally and economically unfeasible. This study aimed to explore the use and reuse of niobium phosphate in aqueous media as a heterogeneous catalyst in furfural production using three types of sugarcane waste. The experiments were designed with temperature (140-180 degrees C), niobium phosphate catalyst load (1-100 %), and time. The maximum xylose productivity was for bagasse (180 degrees C, 90 min, 1 %), straw (160 degrees C, 45 min, 50.5 %), and energy cane (180 degrees C, 120 min, 1 %), respectively 124.1, 82.0, and 68.7 g/kg. The maximum furfural productivity was achieved at 180 degrees C, 100% catalyst load, and time 60, 30, and 60 min for bagasse, straw, and energy cane, which presented productivity of 95, 75, and 65 g/kg, respectively. The catalyst reuse was performed using conventional and makeup methods. Between each reaction, the catalyst was washed only with water. The average furfural productivity after five cycles was 75 and 77 g/kg for conventional and makeup methods, respectively. Given all aspects, the utilization of niobium phosphate goes towards a greener path by decreasing time and temperature to furfural production and hemicellulose removal.