[ Heat Recovery ]
[ Heat Recovery ]
A 3D model of the ammonia heat pump installed in Malmö. Photo © GEA
The high molybdenum content ensures excellent resistance to corrosion, providing long-term reliability in the aggressive conditions created by fluegas condensate.
Combining heat sources Recovery operations at the waste incineration plant work in tandem with another smelly system: Malmö’ s sewage and wastewater treatment operations. After cleaning and processing, the treated water is typically between 12 ° C
and 18 ° C, significantly warmer than surface water. Four large heat pumps recover this warmth, helping to preheat the district-heating water before it is brought to full temperature by the waste incineration system. These heat pumps provide 8 % of the total energy used by the system’ s 100,000 residences. This saves approximately 50,000 tonnes of CO2 a year since wastewater heat capture began in 2017. The evaporators and condensers of the wastewater heat pumps are built from Type 316 stainless steel. Its 2 % molybdenum content provides corrosion resistance against the chlorides and biological compounds in treated wastewater as well as the elevated temperature and pressure on the condenser side. Together, these technologies show how cities can turn waste into warmth. Instead of burning more fuel, the answer to sustainable heating might be in the trash or down the drain. These resourceful district-heating networks demonstrate that with the right infrastructure – and the right materials – urban and industrial waste heat can be recovered almost indefinitely. Molybdenum ensures that even the dirtiest sources of heat can be captured, carried, and used again, serving a cleaner future.
About IMOA
Reproduced with the kind permission of the International Molybdenum Association( IMOA). IMOA is a non-profit trade association representing the majority of the molybdenum industry worldwide. For information visit www. imoa. info