The enhancement of pretreatment and enzymatic hydrolysis of corn stover by FeSO4 pretreatment

FeSO4 was investigated as a catalyst for the pretreatment of corn stover. It was observed that FeSO4 significantly increased the hemicellulose degradation in aqueous solutions heated between 140 and 200 °C with high xylose recovery and low cellulose removal. Optimum pretreatment conditions were 0.1 mol/L FeSO4 at 180 °C for 20 min. The cellulose conversion was 36.4% higher than that pretreated by hot water under the same enzymatic hydrolysis conditions. The hydrolysis efficiencies of treated materials were characterized by reaction rate constants, Km and the activity of cellulase. The results showed that FeSO4 pretreatment apparently removed the hemicellulose, promoted the activity of cellulase and enhanced the accessibility of cellulase to cellulose, thus significantly increased the enzymatic digestibility. FeSO4 pretreatment could disrupt almost all ester linkages between cellulose and hemicellulose. The results obtained indicated that FeSO4 pretreatment as a special pretreatment method could enhance enzymatic hydrolysis of lignocellulosic biomass by destructing chemical composition and altering structural features.

► FeSO4 can improve the removal of hemicellulose and the activity of cellulose.
► This study discussed the role of Fe2+ on the hydrolysis mechanism of cellulose.
► FeSO4 pretreatment is appropriate acidity for enzymatic hydrolysis processing.