Hydrothermal Carbonization is a thermochemical conversion process in which a biomass is processed under hot compressed air to form carbon rich products called as hydrochar. Hydrochar is a hydrophobic, condensed and friable solid product with a fuel property similar to conventional non-renewable energy sources like coal and lignite. Hydrothermal Carbonization performed with Effluent Treatment Plant (ETP) sludge at a temperature range of 180-240℃ for a time period of 4 hours in a hydrothermal autoclave reactor resulted in the production of hydrochar with good energy values thereby ensuring its utilization as an alternative to coal. The energy properties like higher heating value ( MJ Kg-1 ), energetic recovery efficiency () and energy densification () were found to increase after hydrothermal carbonization at 220° for 4 hours. | Hydrochar as an energy alternative to coal: Effect of temperature on hydrothermal carbonization of paper board mill sludge
