Improved glucose yield and concentration of sugarcane bagasse by the pretreatment with ternary deep eutectic solvents and recovery of the pretreated liquid.

In this study, a novel ternary deep eutectic solvents (DES) consisting of choline chloride/PEG/hydroxyethyl sulfonic acid (HSA) was developed to effectively improve glucose yield and concentration of sugarcane bagasse, and the conditions of the pretreatment were optimized by response surface method (RSM). Under the optimal conditions, the maximum glucose concentration (GC) could reach 12.39 g/L (HSA concentration 1.34 %, PEG400, 2.3 h, 150 °C), and the maximum glucose yield (GY) was 0.2497 g/g (HSA concentration 1.41 %, PEG400, 2.1 h, 150 °C). Hemicellulose was completely removed, and the maximum lignin removal rate was 86.89 %. After pretreatment, 95 % of the pretreated liquid can be recycled. Finally, the structural and morphological changes of bagasse before and after pretreatment were investigated by scanning electron microscopy (SEM), Fourier Transform infrared analyzer (FT-IR) and X-ray diffraction (XRD).