Enzymatic Hydrolysis of Soybean Hull Pretreated with Alkali-aided High Shear and Ultrasonication Methods

The use of ethanol as a transportation fuel is increasing day by day due to the adverse impacts of fossil fuels like greenhouse gas emissions and acid rain. Intensive research is being carried out for the successful conversion of biomass to ethanol. This study investigated the use of alkali-aided extrusion and ultrasound as means of pretreatment for soy hull. The pretreated samples were enzymatically hydrolyzed (NREL/TP-510-42629), and reducing sugars in the hydrolysate were analyzed using HPLC (NREL/TP-510-42623). Alkali-aided extrusion and ultrasound pretreatments were recorded of 63% and 62% total sugar yield, respectively, from soybean hull. Potential fermentation inhibitors like HMF and furfural were not found in any of the pretreated samples. This finding suggests that both the pretreatments can be employed for the efficient saccharification of soybean hull.