(513e) Pretreatment and Enzymatic Hydrolysis of Soybean Hulls

Soybean hull is a potential feedstock for production of bio-ethanol due to its high carbohydrates content (≈50%) with about 37% of cellulose. Soybean hulls could be the ideal feedstock for fuel ethanol production, because they are abundant and require no special harvesting and additional transportation costs as they are already in the plant. The objective of this research was to study the performance of dilute acid and steam explosion pretreatment technology on degradation of soybean hulls and to identify the optimum pretreatment and enzymatic hydrolysis conditions for converting soybean hulls into fermentable sugars. The effect of reaction pressure, time, temperature, and acid concentration on enzymatic hydrolysis and final sugar yields were studied. Commercial cellulase and hemicellulase enzymes with concentration of 3% v/w were used for enzymatic analysis. The combination of sulfuric acid (H₂SO₄, 1.5% w/v) and steam injection (140 °C, 30min) efficiently solubilized the hemicellulose with more than 90% pentoses yield and made the material accessible to the cellulase enzymes used in the subsequent enzymatic hydrolysis. The maximum sugar yield was of 36 mg/ml corresponding to 67.6% of the theoretical.