Corn stover for biogas production: Effect of steam explosion pretreatment on the gas yields and on the biodegradation kinetics of the primary structural compounds

This study evaluated the effect of steam explosion on the chemical composition and biomethane potential of corn stover using temperatures ranging between 140 and 220 °C and pretreatment times ranging between 2 and 15 min. Biodegradation kinetics during the anaerobic digestion of untreated and corn stover, pretreated at two different intensities, 140 °C for 5 min and 180 °C for 5 min, were studied in tandem. Results showed that pretreatment at 160 °C for 2 min improved the methane yield by 22%. Harsher pretreatment conditions led to lower hemicellulose contents and methane yields, as well as higher lignin contents, which may be due to the formation of pseudo-lignin. The biodegradation kinetics trial demonstrated that steam explosion enhances the degradation of structural carbohydrates and acid insoluble lignin.