Screw extrude steam explosion: A promising pretreatment of corn stover to enhance enzymatic hydrolysis

A screw extrude steam explosion (SESE) apparatus was designed and introduced to pretreat corn stover continuously for its following enzymatic hydrolysis. SESE parameters temperature (100, 120, 150 °C) and residence time (1, 2, 3 min) were investigated. The enzymatic hydrolysis of corn stover pretreated by SESE and steam explosion (SE) process was carried out and analyzed systematically. A serial of analysis methods were established, and the corn stover before/after the pretreatment were characterized by scanning electron microscope (SEM), X-ray Diffraction (XRD) and Thermal Gravity/Derivative Thermal Gravity Analysis (TG/DTG). After treated by SESE pretreatment at the optimum condition (150 °C, 2 min), the pretreated corn stover exhibited highest enzymatic hydrolysis yield (89%), and rare fermentation inhibitors formed. Characterization results indicated that the highest yield could be attributed to the effective removal of lignin/hemicellulose and destruction of cellulose structure by SESE pretreatment.