Digestibility improvement of aspen leaf with alkaline hydrothermal pretreatment

Effect of alkaline hydrothermal pretreatment on liquefaction,hydrolysis and digestibility of fallen aspen leaves was investigated by biochemical methane potential(BMP) assays.The solubilization and hydrolysis were significantly enhanced,especially for hemi-cellulose and protein.The SCOD and acetic acid concentration were 31.7g/L and 1533mg/L after pretreatment at 170℃,and formation pathways of acetic acid were proposed with mechanism analysis.The specific biogas production increase was highest in BMP assays.The semi-dry digestion system functioned steadily with the feed of hydrolysate,and methane conversion ratio on carbon basis was enhanced to 25.3% at loading rate of 2.65g/(L·d).