Reinforced alkali-pretreatment for enhancing enzymatic hydrolysis of sugarcane bagasse

• Enhanced alkali pretreatment effectively improved enzymatic hydrolysis of cellulose.
• AMIC assisted alkali pretreatment was more efficient in dissolving cellulose.
• Cellulose I structure was highly disrupted with increased area and porosity.
• The glucan and xylan conversion efficiency reached 99.51% and 92.76%, respectively after 72 h hydrolysis.

Microwave irradiation (MWI) and ionic liquid (IL) assisted methods were chosen to strengthen the alkali pretreatment process to improve saccharification efficiency of sugarcane bagasse (SCB). Four different pretreatment approaches namely alkali, IL, MWI-alkali and IL-alkali pretreatments were compared. The chemical composition, morphology and crystal performance of the substrates were analyzed by the standardized methods of the National Renewable Energy Laboratory, field emission scanning electron microscope (SEM) and X-ray diffraction (XRD), respectively. IL assisted treatment brought the highest lignin removal (78.51%), and the glucan and xylan conversion achieved 99.51% and 92.76%, respectively, after 72 h of enzymatic hydrolysis. The similar effect occurred for MWI assisted alkali-pretreatment approach. SEM and XRD analyses showed that the strengthened process obviously changed the structure and crystallinity of the substrates. Moreover, as a persuasive tool, the fractal-like theory was used to study the enzymatic hydrolysis kinetics.