Sludge processing by anaerobic digestion and superheated steam drying

This paper considers the combination of anaerobic digestion and superheated steam (SHS) drying in sludge processing. Anaerobic digestion reduces the quantity of sludge and produces methane that can be utilized in supplying the thermal energy requirement of thermal drying. In SHS drying, a significant fraction of dryer thermal energy input can be recovered and used to more than satisfy the heat requirement in maintaining the digester operating temperature. Thermal energy analysis shows that the combination of anaerobic digestion and SHS drying can achieve thermal energy self-sufficiency by manipulating process variables.