Hydrothermal treatment enhances energy recovery from pig manure digestate and improves the properties of residues.Energy recovery from biowaste is of high significance for a sustainable society.  Herein, hydrothermal treatment (HT) was applied to valorize pig manure digestate.  The effects of hydrothermal operational parameters, including temperature (130-250 °C), residence time (15-90 min), and total solid (TS) concentration (10%-20%), on reducing sugar yield were investigated in this study.  Among them, hydrothermal temperature was identified as the most important factor influencing reducing sugar yield, followed by the TS concentration and time.  The optimal hydrothermal conditions for the pig manure digestate were 175.6 °C, 35.4 min and a TS concentration of 10% with a reduced sugar yield of 9.81 mg gTS-1.  These findings indicated that the hydrothermal process might be an effective technique to recover energy from the digestate of livestock and poultry manure and to improve the residual digestate for subsequent utilization.
THERM