Optimization and Purification of Levulinic Acid Extracted from Bagasse

Levulinic acid (LA) is an important biomass-based chemical. The preparation of LA from bagasse is of great practical significance for the comprehensive and efficient utilization of biomass. Biomass bagasse is mainly composed of cellulose, hemicellulose, and lignin. The cellulose is mainly degraded to glucose, and hemicellulose is mainly degraded to xylose, with dilute acid treatment at high temperature. In this research, we produced the LA from bagasse with dilute acid treatment at high temperature. The influences of residence time (10–60 min), reaction temperature (170–240 °C), liquid-to-solid ratio (5:1–25:1 mL/g), and acid concentration (1–5%) on the synthesis of LA were investigated by statistical methods, achieving a maximum LA yield of 16.25%. Additionally, LA was isolated and extracted from bagasses hydrolysate by ion exchange and vacuum distillation. The adsorption capacity of different resins was determined and compared. The optimal resin to acquire better adsorption capacity was determined. The better adsorption capacity was obtained when the D301 resin was selected as the filter for ion exchange. The height-to-diameter rate, eluent flow rate, elution volume of ion exchange column were 10, 0.84 BV/h, 56.4 mL, respectively. The eluent was then distilled under vacuum, collecting the components at 130–140 °C. The total yield and purity of LA were 67.1% and 78%, respectively.