Influence of biphasic phenoxyethanol-alkaline pretreatment on the correlation between inter-structure and enzymatic hydrolysis in bamboo residues.

The effective promotion of delignification (67.6%) and xylan removal (44.8%) from bamboo residues using a 2-phenoxyethanol/sodium hydroxide solution (P/A) system is demonstrated, while simultaneously enriching oligosaccharides contents of the pre-hydrolysate to 10.2 g/L. Increasing the P/A ratio from 0:1 to 4:1 improves the enzymatic digestibility of the substrates from 55.7% to 70.1% at 100 °C and from 73.8% to 83.7% at 120 °C. Furthermore, partial correlation analysis demonstrates that the physiochemical properties, including delignification, xylan removal, and crystallinity, show a significant positive correlation with enzymatic hydrolysis efficiency. Higher temperatures and P/A ratios during alkaline biphasic pretreatment promote the shrinkage of plant cells and delignification, with temperature being a particularly significant driver. These findings provide valuable insights into the alkaline and biphasic pretreatment of biomass and facilitate the optimization of the bio-refining system.