Enhanced Enzymatic Digestibility of Sugarcane Bagasse Pretreated by Ionic Liquids

The pretreatment effects of three ionic liquids (ILs) (1-ethyl-3-methyl imidazolium acetate ([Emim]Ac), 1-butyl-3-methyl imidazolium chloride ([Bmim]Cl), and 1-allyl-3-methyl imidazolium chloride ([Amim]Cl)) on the recalcitrance and enzymatic digestibility of sugarcane bagasse (SCB) were investigated and [Emim]Ac was found to have the highest efficiency for SOB pretreatment among the three ILs. The structures of regenerated SOB pretreated with [Emim]Ac were characterized by X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The crystallinity index (Crl) of the SOB pretreated with [Emim]Ac at 140 degrees C for 0.5 h was significantly reduced from 41.65% to 18.74%, indicating the significant decrease of recalcitrance of the pretreated SOB. Additionally, a negative linear correlation was found between Crl and initial hydrolysis rate of the pretreated SOB. Enzymatic conversion of the pretreated SOB was enhanced from 4.85% to 64.99% The present work paves the way for biorefinery of lignocellulosic biomass.