Valorization of sugarcane bagasse C5-fraction by furfural production mediated by renewable glycine-based ionic liquid

In this work, a green method to produce furfural from sugarcane bagasse (SCB) acid hydrolysates is proposed via a route mediated by a renewable glycine-based ionic liquid, [GlyIm][HSO4], and using a green biphasic system composed of water (reaction solvent) and 2-methyltetrahydrofuran (2-MeTHF - extraction solvent) to avoid side reactions and optimize furfural yields. The process was carried out in two steps: (i) SCB acid hydrolysis and (ii) furfural production from the acid hydrolysates. The best conditions for C5 sugar extraction from sugarcane bagasse (150 °C, 30 min, 4% v/v H2SO4) were determined based on a 23 full factorial design. The best conditions extracted up to 85% of hemicellulose, mainly as xylose, resulting in a solid prone to further valorization as a co-product. Optimized conditions for furfural production using xylose as the sugar source (180 °C for 10 min using 10 eq. of ionic liquid) were also determined using a 23 full factorial design and resulted in 87 ± 2% of furfural yield. According to the Design of Experiments (DoE), higher furfural yields were achieved at 180 °C, regardless of the reaction time (10 or 60 min). By applying the optimized conditions for furfural production in the sugarcane hydrolysates, a 90% furfural yield was achieved, and no lignin interference was observed in furfural production.