Co-production of fermentable glucose, xylose equivalents, and HBS-lignin from sugarcane bagasse through a FeCl3-catalyzed EG/H2O pretreatment

In this study, a FeCl3-catalyzed ethylene glycol/water (FeCl3-EG/H2O) pretreatment was developed and applied for the enzymatic hydrolysis of sugarcane bagasse. The results indicated that FeCl3-EG/H2O pretreatment showed excellent selectivity for the removal of both hemicellulose (-100 %) and lignin (-65.3 %), leading to the residual pretreated solid with high cellulose content (-74.7 %) that could be easily for subsequent enzymatic saccharification. The yield of glucose after enzymatic hydrolysis was almost linearly positively correlated with the removal of lignin and xylan, and the maximum glucose yield obtained the using method was 91.5 %, which was 4.1-fold as large as that without pretreatment. The SEM, FT-IR, and XRD analysis indicated that the improvement of enzyme digestibility of sugarcane bagasse was not only related to the selectively remove of some component barriers, but was also correlated with the changes of surface morphology and internal structure. Furthermore, part of the hemicellulose and lignin in sugarcane bagasse also can be recovered in xylose equivalents, furfural, and high boiling solvent lignin (HBS-lignin) with the yields of 84.0 %, 12.5 %, and 60.1 %, respectively. It can be concluded that the FeCl3-EG/H2O pretreatment developed in this study was effective in achieving the hierarchic conversion and utilization of bagasse.

Automated summary

The FeCl3-EG/H2O pretreatment method developed in this study showed excellent selectivity in removing hemicellulose and lignin from sugarcane bagasse, resulting in high cellulose content and glucose yield after enzymatic hydrolysis. The method significantly improved the enzymatic digestibility of sugarcane bagasse and showed potential for hierarchical conversion and utilization of the biomass.