Turboden has announced the successful start-up of what it claims is the world’s largest steam-producing heat pump in Tervakoski, Finland.

The system is now fully operational at a paper mill belonging to Austrian speciality paper manufacturer Delfort and is reported to be overperforming, with a coefficient of performance 10% above the guaranteed value.

Delfort required a solution capable of supplying its production with fully decarbonised steam, while guaranteeing the same quality, reliability and continuity traditionally provided by fossil-fuel boilers.  

Part of the Mitsubishi Heavy Industries Group, Turboden installed a large heat pump coupled with a mechanical vapour recompression capable of generating 12 MWth (megawatt thermal) of superheated steam at 3.4 bar(a) (bar absolute), lifting the temperature up to 150–180°C. The system recovers low-grade waste heat from the industrial process and upgrades it using CO₂-free electricity.

Turboden says the installation is the largest steam-producing heat pump currently in operation and demonstrates the potential of CO₂-free heat technologies to replace fossil-fuel-based boilers in demanding industrial applications requiring steam beyond 150°C.

The project is expected to avoid approximately 19,000 t/y of CO₂ emissions.  

Everllence to deliver mega heat pump for Boston’s district energy network

Meanwhile, Everllence (formerly MAN Energy Solutions) has announced a new industrial-scale heat pump project in partnership with Vicinity Energy, owner and operator of district energy systems in the US. The project will support the installation of what it claims will be the largest steam heat pump in the world at the Kendall Station facility in Cambridge, Massachusetts.  

The heat pump will extract low-grade heat from the Charles River and operate primarily on renewable electricity. The project integrates a vapour compression cycle with steam compression, enabling the generation of high-pressure steam at up to 50 bar and over 300°C. The system incorporates two high-efficiency, multi-shaft integrally geared compressors: type RG40-8 for refrigerant compression and type RG63-6 for steam compression.

With an output of 35 MWth, the installation will be capable of providing around 50 t/h of steam and will serve more than 70mn ft² of building space. Branded as eSteam, the decarbonised steam will be distributed to homes and businesses, as well as medical and educational institutions via Boston’s existing district heating network, replacing natural gas-fired boilers. The heat pump is expected to enter operation in 2028.