Goals are achieved in collaboration: the need for primary energy reduced by 33% at Apetit
Since autumn 2023 heat pumps have been running at the Adven’s energy site that produces energy at Apetit’s factory in Säkylä, Finland. They harness the waste heat from four of the customer’s refrigeration plants and recycle it back into the district heating network and for equipment washing purposes.
Already during the first six months, more than 70% of the energy required for district heating and washing has been produced with recovered heat. And the share will only increase as the harvesting season will soon be in full swing.
The factories producing Apetit’s frozen vegetables and foods are located in Säkylä, Finland. The company’s approximately 140 contract farmers cultivate more than 30 million kilos of vegetables annually for processing at the Säkylä frozen food factory.
The preparation of frozen foods requires hot water and process steam. In addition, heat energy is needed in the property heating of the approximately 20 000 square meter factory area and in the daily washing of production equipment. Energy is consumed especially during the harvesting season from summer till autumn. Earlier challenges had been large fluctuations in energy demand during the year and an outdated energy solution.
“At Apetit, we have determinedly moved towards renewable energy solutions over the past few years. Our goal is to reduce energy-related CO2 emissions by 75 percent by the end of 2025. The new energy solution of the Säkylä frozen food factory is an important part of realizing this goal”, says Esa Mäki, CEO of Apetit.
The need for primary energy has decreased by 33% thanks to heat recovery
The energy solution of the Säkylä plant was previously based on fossil fuels, and a bio-boiler plant was already in the thoughts. When Adven joined, the first focus was on how the overall need for energy could be reduced, for example, by utilizing the residuals that always occurs in industrial processes.
The answer was found in the recovery of waste heat produced by the refrigeration plants of the frozen food factory. Now four heat pumps in Adven’s energy center harness energy previously blown into the open air. Heat is transferred from the refrigeration plants to the energy center via the heat recovery system. The system includes heat exchangers, piping, control systems and automation that optimizes recovery.
What are the results so far?
The start has been promising and just after the first six months more than 70% of the energy used for property heating and washing production equipment has been produced with heat recovery. And this was during a colder than usual winter. The remaining portion is obtained from process steam. With the help of the new heat recovery solution the need for primary energy has been reduced by a third.
“The share of recovered energy will increase considerably as the harvesting season kicks off and the cold treatment of frozen vegetable production is most intense. There is a lot to recover then”, says Pasi Kolehmainen, Director of Heat Pump Solutions at Adven, who has also been behind the heat recovery idea.
Nothing is wasted in heat recovery either: any surplus is stored in a massive six hundred cubic meter accumulator, from which heat can be discharged for different purposes.
The peeling process became more efficient with the increased steam pressure of the new boiler plant
The process steam needed for the processing of crops is produced in a modern steam boiler house, where for example biogas can be used as fuel. Adven also implemented the new steam boiler plant, and in connection with the renovation, the steam pressure was increased to 16 bar, thanks to which the vegetable peeling process is now more efficient and precise than before.
“It has been great to do this project together with the Apetit people. The condensing systems of their two engine rooms were also renewed as an additional part of the extensive project”, praises Kolehmainen.
Challenges are solved in a spirit of partnership
In accordance with its Energy as a Service model, Adven is responsible for operating both the boiler plant and heat recovery. Adven has also been responsible for the investments required by the project. The planning, implementation, and management of complex energy solutions such as the one now implemented for Apetit require expertise that companies rarely possess themselves.
“The cooperation in renewing the energy solution has been smooth and already in the initial phase we have reached the predicted level in the utilization of heat recovery. A long-term partnership provides security, and in the spirit of continuous improvement, we are already thinking together about various new further development opportunities”, says Ari Kulmala, Apetit’s production director.
Facts about the solution:
- The Säkylä plant processes approximately 30 million kilos of domestic vegetables into frozen foods every year.
- With the new energy solution, the share of renewable energy sources is over 60 %.
- The carbon footprint of energy production at Säkylä factory has decreased by about 40 percent, or more than 2,000 tons per year.
- The modern energy solution has 4 heat pumps with a total output of more than 2000kW, which recover condensate energy from refrigeration plants for district heating and equipment washing, which corresponds to more than 70% of the energy needed for this (first 6 months).
Contact for additional information:
Kristaps Greidāns, Industry Lead, Food & Beverage, kristaps.greidans@adven.com, tel. +371 22 008 455
Read more:
Recovery of residues and waste streams
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