Hydrothermal carbonization of anaerobically digested sewage sludge for hydrochar production

Hydrothermal carbonization (HTC) can process anaerobic digestion effluent (ADE) from sewage sludge into hydrochar and liquor. The objective of this study was to assess the effects HTC temperature, time, initial ADE pH on yields properties conducted at different (original ~8.2 modified ~6.8), temperatures (180 260 °C) times (30 70 min) following a central composite design. Hydrochar original ranged 80% 62% to73%, respectively. Higher resulted in lower liquor yields. obtained had low carbon content, high ash H/C ratio, higher heating value, suggesting that it has little potential as solid fuel, more soil amendment. liquor's composition chemical oxygen demand indicate for recirculation digestion.