Hydrothermal Conversion of Bamboo: Identification and Distribution of the Components in Solid Residue, Water-Soluble and Acetone-Soluble Fractions

Hydrothermal conversion is an important thermochemical process to upgrade low-cost lignocellulose into valuable chemicals or fuels. Studies on hydrothermal products compositions and their distributions are of great significance in lignocellulose upgradation. In this work, the major products of bamboo hydrothermally treated at 180–240 °C for 3–60 min and their distributions were comparatively studied. According to the hydrothermal conditions, the hydrothermal products were composed of 37.11–89.98% of solid residues, 4.51–20.41% of water-soluble fractions (WS), and 4.23–16.17% of acetone-soluble fractions (AS). The products in WS fractions mainly consisted of furfural (FF), 5-hydroxymethylfurfural (HMF), and phenolic compounds, while the products in AS fractions were mainly 4-hydroxy-4-methyl-2-pentanone and complex aromatic compounds with multibenzene rings. Additionally, the highest yields of FF (33.4%) and HMF (15.6%) were observed at 200 °C for 60 min and 240 °C for 60 min, respectively.