Combined Experiences of Thermal Hydrolysis and Anaerobic Digestion

First experiments in US 1976 – Haug et al

• Thermal pre-treatment prior to anaerobic digestion may result in net energy production from the system because of increased biodegradability and reduced digester heating requirements.
• Recycling of liquid side streams from thermally pre-treated digested sludge should not significantly increase the oxygen demand on a biological treatment system.
• Odorous compounds normally associated with heat treatment are significantly reduced during digestion of thermally pre-treated sludge.