Deconstructing recalcitrant Miscanthus with alkaline peroxide and electrolyzed water

A two-stage pretreatment method was proposed and tested for deconstruction of recalcitrant Miscanthus. During a 1st pretreatment at 50 °C, 1.0–4.0% alkaline peroxide solutions were used to partially remove hemicellulose and lignin. The remaining solids were subjected to a 2nd pretreatment at 121 °C with electrolyzed water. Using 15 filter paper units of cellulase per gram cellulose, a digestibility of 95% was achieved by the two-stage method, which was higher than 81% obtained from a 1% H2SO4 pretreatment (200 °C, 8 min). A mass balance for the two-stage process showed that 63% hemicellulose and 64% lignin were removed from the Miscanthus samples after the 1st pretreatment. The Scanning Electron Microscopy images and Fourier Transform Infrared Spectroscopy spectra revealed that after the 1st pretreatment, crystalline cellulose fibers were partially exposed and the linkages between residual lignin and hemicellulose disappeared. After the 2nd pretreatment, cellulose fibers were completely exposed even with cracks developed.