A complete sludge treatment reduction process which combines high pressure and temperature.
Thermal hydrolysis achieves enhanced treated sludge and improves the final sludge cake dryness. The treated sludge can then be recovered for agricultural use. The increased biogas produced by the anaerobic digestion can be used for producing green electricity or can be injected after treatment in the gas grid.
What is Thermal Hydrolysis?
The thermal hydrolysis process (THP) makes biosolid waste material or sludge more biodegradable, improving digestibility and the efficiency of subsequent sludge treatment processes. The thickened sludge is heated up to between 150 and 165 degrees Celsius, at a pressure of around seven bars. The pressure is then rapidly released causing cells in the sludge to rupture, making it more digestible to microbes.
Thermal Hydrolysis Plant
A thermal hydrolysis plant, such as the Veolia Bio Thelys system, processes all types of organic municipal and industrial sludge. The quality of the sludge is improved, the volume is reduced and biogas production from digestion is increased. The plant process breaks down the organic matter in the sludge making it more digestible for the microbes used in the anaerobic digester. Biogas derived from the digester can be used for renewable, green energy and the drier sludge cake can be recovered for agricultural use.
Benefits of Thermal Hydrolysis
Thermal hydrolysis provides many wastewater treatment benefits:
- The resulting sludge cake presents lower odour levels
- Biosolids can be used as an effective and low-cost fertilizer
- Enhanced biogas production can be used for electricity production or grid injection
- The reduced biosolid mass and volume decreases the cost of residuals management