At its site in Hilden near Düsseldorf, 3M produces, among other products, graphic and decorative films, high-performance adhesive tapes, and respiratory protection equipment. Around 750 employees work on the approximately 222,000 m² site.
The energy supply is provided by two single-flame shell boilers fired with natural gas. After more than 40 years of operation, the plant no longer met the requirements of the German 44th Federal Immission Control Ordinance (44. BImSchV), particularly with regard to NOx emissions exceeding 180 mg/Nm³.
The objective of the project was to adapt the existing boiler system to current emission limits and ensure continued safe and efficient operation – without completely replacing the plant.
Step-by-step modernisation of the existing combustion plant through the adaptation of burner technology and the integration of flue gas recirculation to ensure compliance with emission limits.
To ensure compliance with the requirements of the 44th BImSchV, the plant was first optimised through targeted adjustments to the gas nozzle arrays. Based on the results achieved, the decision was subsequently made to implement flue gas recirculation (FGR) to further reduce NOx emissions.
By combining these methods, emission levels were reduced from over 180 mg/Nm³ to below 90 mg/Nm³. This means that the legal requirements are not only met but significantly undercut – whilst the existing boiler plant continues to operate.
The existing plant technology could largely be retained. Only one fan was replaced due to a lack of performance reserves. The implementation took place in close consultation with the operator and comprised engineering, delivery, installation and commissioning.
The SAACKE solution in detail
At the heart of the modernisation was the targeted optimisation of combustion through the adaptation of the existing burner components, combined with flue gas recirculation. By recirculating a defined proportion of the flue gas back into the combustion process, the flame temperature is reduced, thereby significantly lowering the formation of nitrogen oxides.
A particular challenge was achieving the required emission reduction in an existing plant with limited scope for technical modifications. The significant gap between the existing emission values and the legal requirements necessitated a combination of several measures.
Thanks to a step-by-step approach, the optimisation potential of the existing burners was first fully exploited before flue gas recirculation was implemented as a supplementary measure. This approach enabled a technically and economically viable solution in which the existing infrastructure was largely retained.
The coordination of all components and the fine-tuning of the plant took place during commissioning, ensuring stable, efficient and low-emission operation.
- Significant reduction of NOx emissions to below 90 mg/Nm³
- Clear compliance with the requirements of the 44th BImSchV
- Continued operation of the existing boiler system without full replacement
- Resource-efficient modernization by retaining existing equipment
- Cost-effective solution through targeted retrofit measures
The project at 3M in Hilden demonstrates that even older installations can be successfully adapted to current emission requirements through targeted modernization measures. By combining technical optimization with additional measures such as flue gas recirculation, a sustainable reduction in emissions was achieved without the need for complete plant replacement.
SAACKE thus provides economical and resource-efficient solutions to ensure the long-term operation of combustion systems.