Viegand Maagøe assisted in making a big dairy fossil free
Arla in Vimmerby wanted to eliminate fossil oil. In collaboration with Adven, responsible for the dairy’s energy production, the processes were optimized, enabling the dairy to become fossil-free.
Goodbye oil
“Fossil-free Arla – helping the environment and saving millions.” That was the positive and green message about Arla’s dairy in Vimmerby in the fall of 2023.
The large dairy, with an extensive production of milk powder, bids farewell to the last drop of fossil oil at the beginning of 2024. This marks the culmination of a long and successful collaboration between the energy supplier Adven, Viegand Maagøe, and Arla.
It all began in 2019 when the dairy needed to find a new operator for its energy plant. A requirement for the new operator was to deliver fossil-free energy. Consequently, Adven reached out to Viegand Maagøe, which has been assisting in mapping and optimizing the energy processes at the Swedish dairy since 2010.
How we did it
Viegand Maagøe conducted a detailed screening of the processes, forming the basis for a series of project proposals for optimization. Adven was responsible for supplying the energy and managed the upgrade of the wood chip boiler, installation of the flue gas condenser, and heat pumps, while we handled the reconstruction inside the dairy.
Indefra og ud
The optimizations were discovered using a classic Viegand Maagøe approach, where the processes are studied from the inside out, explains project manager Bjørn Skjødt Sørensen.
“In essence, we’re not particularly concerned about how efficient the boiler is, but we’re interested in ensuring that the process uses as little energy as possible. Otherwise, one could install as many heat pumps as they want without reaching the desired goal,” he explains.
The Technical Solution
The technical optimizations of the production processes have been numerous, but among the primary focus areas were:
- Optimization of heat recovery from the evaporators
- Reduction of steam requirements in the spray drying process
- Changing the hot water system from 115°C to 90°C, allowing the hot water to be produced by heat pumps instead of using steam from the wood chip boiler. This way, the dairy avoids unnecessary energy usage in areas such as heating, cleaning, pasteurization, and other processes where 115-degree hot water isn’t necessary. This action frees up capacity in the wood chip boiler, rendering the oil boilers redundant.
In the spray towers, adjustments have been made to the preheating to create energy savings.
