Kinetic study for Fe(NO3)3 catalyzed hemicellulose hydrolysis of different corn stover silages

Five inorganic salts, ZnCl2, FeSO4, Fe2(SO4)3, FeCl3 and Fe(NO3)3 were chosen as catalysts to determine their effects on hemicellulose hydrolysis in control silage (no silage additive), and the results indicated that Fe(NO3)3 was the most efficient catalyst for hemicellulose hydrolysis. The kinetics of Fe(NO3)3 catalyzed hydrolysis for control silage and acid silage (treatment with HNO3) were investigated at various pretreatment conditions. The results demonstrated that Saeman model was well consistent with Fe(NO3)3 catalyzed hydrolysis reaction for corn stover silage, and kinetic parameters for this model were developed by the Arrhenius equation. Optimum pretreatment conditions were 0.05 M Fe(NO3)3 at 150 °C for 21.2 min for control silage and 12.7 min for acid silage, which obtained the maximum xylose yields 81.66% and 93.36% of initial xylan, respectively. The activation energies for hemicellulose hydrolysis in control and acid silage ranged from 44.35 to 86.14 kJ/mol and from 3.11 to 34.11 kJ/mol, respectively.