Dissolution of Lignocellulosic Biomass With Acidic Hot Water

Flowthrough pretreatment provides a promising platform to dissolution of lignocellulosic biomass to generate high yields of fermentable sugars and lignin for biofuels productions. In this study, dissolution of xylan, lignin, and cellulose from poplar wood were significantly enhanced by uncatalyzed and catalyzed flowthrough pretreatment when the operation temperature was raised from 220°C to 300°C, resulting in more than 98% solid solubilization. Up to 50% of original xylan was converted to xylose in the hydrolysate and the rest xylan to xylan oligomers without detectable degradation products formed. Up to 55% of original cellulose was degraded into glucose during pretreatment. More than 90% lignin with low molecular weight was recovered from the hydroyzate. In addition, the digestibility of cellulose and hemicellulose in the pretreated whole slurries was characterized under a range of operation conditions. The new insights gained will lead to obtain even higher yields of fermentable sugars and reactive lignin for biofuels production at acceptable concentrations for hybrid biochemical/thermochemical processing.