Schweizer Zucker AG operates one of Switzerland’s two sugar factories in Aarberg. At this historic site, which has been in operation since 1912, large quantities of Swiss sugar beets are processed each year. Approximately 160 employees, along with seasonal workers, ensure a reliable supply of sugar to Switzerland during the harvest season.The construction of the new wood-fired power plant (HKW Aarberg), which now supplies a large portion of the steam required by SZU, presented an opportunity to comprehensively modernize the boiler house, which is over 100 years old. The company was looking for a partner who could provide holistic support for the modernization and coordinate various technical disciplines. «With STEBATEC, we had a single point of contact for various disciplines,» says Christian Marti, Head of Engineering & Maintenance at the Aarberg plant, describing the initial situation.
Historic facility, modern requirements
The modernization of the two water-tube boilers—each with a capacity of 18.5 MW at 42 bar and 450 °C superheated steam—posed significant challenges for planning and implementation. In addition to upgrading the safety systems, existing systems had to be integrated, interface issues resolved, and the plant gradually brought up to modern standards.
Key challenges:
- Modernization of a boiler house over 100 years old while maintaining continuous operation
- Retrofit of the two water-tube boilers to current safety and automation standards
- Integration of the new control system into the existing process control system
- Dismantling and replacing the backup fuel oil supply system, switching from a manual to an automated system
- Replacing the burners to enable tri-fuel operation (fuel oil/natural gas/biogas)
- Implementing a new operating strategy following the integration of the wood-fired power plant
With the new operating strategy, the boilers now run in a resource-efficient, reduced-capacity mode and can be ramped up to full load again within a very short time if necessary. This results in more efficient use of energy, infrastructure, and resources.
Flexible and solution-oriented
The project implementation was characterized by short decision-making paths, a high degree of flexibility, and a practical approach. STEBATEC responded to spontaneous requests quickly and without complications. «It was never about taking the easiest path, but always about finding the most effective and efficient solution for us,» says Christian Marti, summarizing the collaboration.
An unexpected extension of the sugar beet harvest also led to a significant shortening of the time window for work on Boiler 1. Instead of the planned 5.5 months, only four months were available. Through close coordination between STEBATEC, third-party vendors, and SVTI, a viable solution was developed on the spot, preventing the project from being postponed by a year.
Sustainable added value for operations
The modernization brings long-term benefits to Schweizer Zucker AG in Aarberg and improves both the efficiency and operational safety of the plant.
Results achieved:
- Increased energy efficiency
- Improved operational safety
- Higher level of automation and simplified operation
- More flexible fuel utilization through natural gas, biogas, and heating oil operation
- Reduced operational complexity
Reduced workload for operating personnel through simplified processes
With the successful modernization, the boiler house at Schweizer Zucker AG in Aarberg is optimally positioned to meet future requirements. Christian Marti summarizes: «We are now benefiting from more efficient and safer operations. What is particularly valuable to us is that STEBATEC acts as a comprehensive partner who integrates the various technical areas and continues to provide us with long-term support even after the project’s completion.»
