Felleskjøpet, a Norwegian producer of agricultural supplies since 1950, is committed to halving its greenhouse gas emissions by 2030. In its production process, typically steam-based thermal treatment is used to minimize chemical usage and ensure high-quality raw materials.
To further reduce its environmental impact and energy costs, Felleskjøpet has partnered with Aneo Industry to implement the “Frigg” heat pump technology. This innovative solution upgrades waste heat from the production process into valuable steam, which replaces traditional boiler steam production. The high-temperature heat pump efficiently generates the process steam needed for the drying and hygienisation of raw materials, reducing the energy consumption of the production line by over 65% and saving 5 GWh annually.
The pilot plant in Trondheim, Norway, is the world’s first to employ a steam-generating heat pump in the feed industry. The successful implementation of this technology marks a significant milestone and paves the way for its expansion to other facilities, further advancing sustainable, energy-efficient drying solution.
Production process and heat pump integration
The production process relies on steam for the hygienisation of raw materials after dosing and mixing. The heat pump solution efficiently captures waste heat from the exhaust humid air produced during the cooling and drying of pellets, typically around 65°C, and upgrades it to generate the necessary process steam for hygienisation (see Figure 1). Prior to the heat pump’s implementation, this waste heat was released outdoors. Now, the heat pump transforms this wasted energy into valuable steam, producing two tons of steam per hour. The system achieves an efficiency gain of 67% (COP: 3.1 to 3.4, depending on operating conditions), with a temperature lift of 90 to 100°C.
Figure 1: Sketch of the petfood pellets process at Felleskjøpet with heat recycling and upgrading
The basic concept can be summarized by the three following steps:
- recovery of waste heat from the chiller/dryer operation (heat source)
- upgrade of waste heat to process steam at 2 barA and 130°C by heat pump
- supply of process steam to thermal mixer (heat sink)
Benefits
The primary benefit of the implemented process is a significant reduction in steam production from the electric steam generator of the production plant. Additional key benefits include:
- Reduction of electrical peak load at approx. 1.2 MW el → Enables production expansion
- Power savings in steam generation approx. 5.4 GWh per year
- Testing functionality for Roll/out factories
- Reduction of odour pollution due to less moisture in the factory exhaust air
- CO2 emission reduction
Key facts
| Dryer type | Packed bed, counterflow chiller/dryer |
| Drying product(s) | Bulk solids, typically feed or food |
| Drying medium | Air |
| Operation | Continuous |
| Product conveying | Gravity |
| Heating medium temperature | To the dryer/cooler: ambient air. To the hygienizer: 130 °C |
| Heat sources | Ambient air, heat pump |
| Heat pump capacity | 1.5 MW |
| Flow temperature heat pump | 120-130 °C |
| Refrigerant | Ammonia (R717) and water (R718) (cascade HP) |
| Drying time | 30 minutes drying/chilling time |
| Start of operation | 2024 |
| Capacity | 2000 kg/h water evaporation |
| Dryer Dimensions | 4*4*5 length |
| Outlet condition drying medium | 65°C, 35% relative humidity |
| Direct heat recovery | Yes |
| Heat source for heat pump | Excess heat from chilling/drying air |
| Challenges | retrofit into an existing plant, flexible operation of heat pump during recipe changes |
| Tracked parameters | Temperatures, COPs, specific energy consumption, specific air consumption, relative humidity Dataset of 200 + parameters to monitor |
More information
This information was extracted by Aneo. More information is provided here.