Thermal recovery of sewage sludge at the Hagenow wastewater treatment plant
The operator of the AZV Hagenow municipal wastewater treatment plant has signed a contract with FMI Process for the manufacture, installation and commissioning of a TERMIPAK® 800 fluidised bed furnace, as well as maintenance of the unit for 5 years.
Abwasserzweckverband (AZV) Hagenow treats municipal and industrial wastewater at 17 wastewater treatment plants (WWTPs) in north-eastern Germany.
6,000 tonnes per year of digested sewage sludge with a dry matter content of between 22 and 28% (approx. 1,500 t/year of dry matter) will be thermally recovered at the Hagenow WWTP from the commissioning of the plant scheduled for the end of 2024.
Thermal treatment reduces the volume of sludge by 90%. The TERMIPAK® 800, a modular construction covering an area of less than 300 m², has a treatment capacity of 0.8 t/h of raw sludge for an annual operating time of 7,500 hours.
The fluidised bed furnace has a thermal capacity of 1.15 MWth.
The sludge is dewatered using centrifuges, with a minimum dryness of 22%. The installation operates using biogas produced from sludge digestion. To move towards autothermal operation, an upstream drying installation uses waste energy from the flue gases as a heat source. The ashes from thermal recovery are recovered using bag filters.
The TERMIPAK® 800 furnace is made of high-tech steel alloy, without refractory bricks, and the unit is covered by a European patent. This facilitates the start-up and shut-down of the furnace, and the plant can be started up in a few hours.
The extraction of phosphorus by precipitation and separation from the liquid phase of sewage sludge is carried out by the operator using the MAP (magnesium ammonium phosphate precipitation) process.
TERMIPAK® 800
» Modular and compact installation
» No building required
» Easy start-up/shutdown operations
» Throughput: 2,000–6,000 t/year (1,500 tMS/a)
» Sludge dryness from 22%
» Fluidised bed at 850 °C
» Low energy consumption thanks to biogas and autothermal operation
» Heat recovery: hot water generation
» Flue gas treatment
» Continuous analysis of emissions
FMI Process is part of the SNF Group and has been manufacturing fluidised bed incinerators for sewage sludge for over 25 years.
FMI Process has references in France and Italy with incineration capacities ranging from 2,000 to 80,000 tonnes per year.