(639g) Biofuel Precursor Solubilized Carbohydrates Production from Lignocellulosic Biomass Using Solvent Liquefaction

High cost of enzyme production and slow rates of bioconversion pose significant challenges to the growth of cellulosic ethanol production technology via enzymatic hydrolysis. Herein, we report a completely non-enzymatic sugar production route from lignocellulosic biomass using THF/water mixture with dilute sulfuric acid to improve upon these challenges. Typically, lignin and hemicellulose together block access to cellulose in woody biomass making the release of glucose difficult. Additionally, intensive hydrogen bonding in cellulose makes it challenging to break down the structure of crystalline cellulose. Both the factors above contribute to slow rates of enzymatic reaction. In this study, a two-step solvent liquefaction of red oak was employed in which lignin and hemicellulose were solubilized in at 120 ^oC, and the following step was used to rapidly deconstruct the cellulose-rich pulp from pretreatment into solubilized carbohydrates at 220 ^oC within only 2 min of reaction. The final solubilized carbohydrates could be easily converted to fermentable monosacchrides for bioethanol production by dilute acid hydrolysis. The two-step process was able to achieve 67% and 94% of theoretical glucose and xylose yields, respectively, which are comparable with standard enzymatic hydrolysis results but at approximately three orders of increase in sugar production rates. Furthermore, THF is a relatively low cost solvent and easy to flash off from aqueous sugar solution compared to other expensive high boiling solvents studied for sugar production from biomass. It would be interesting to evaluate the economic feasibility and benefits of this process in comparison to enzymatic hydrolysis for industrial scale application.