Norske Skog produces paper for magazines and newspaper. For its Saugbrugs paper mill in Halden, Norway, Norske Skog chose a Pentair Haffmans’ biogas upgrading system to process biogas from the sewage treatment plant, and generate an additional value stream. To celebrate the opening of the Saugbrugs biogas and nano-pulp plant, an open day for the whole community of Halden, which included an official ceremony with King Harald of Norway, was held in early April.
Norske Skog operates nine paper mills worldwide, and the Saugbrugs plant is one of the company’s largest and most energy-efficient. With a history that dates back to 1575, the site currently has three supercalendered magazine paper production machines with a combined 500,000 tons annual capacity. Norske Skog’s move into biogas production strengthens the mill’s competitiveness, and provides a positive addition to renewable energy usage in the region.
The biogas plant is connected to the existing sewage treatment plant and uses sewage sludge from the paper production. Pentair Haffmans supplied a multi-stage membrane-based biogas upgrading system with a raw gas capacity of 600 Nm3/h that is upgraded to approximately 490 Nm3/h of biomethane. The biomethane is compressed to CNG and sold to an external gas supplier with the intention of using the gas to power a fleet of 70 buses and trucks in the region.
The compact structure of Pentair Haffmans’ biogas upgrading system was a major advantage for easy transport and installation. All components were preassembled on cubic steel skids and were converted into a weather-proof building on-site by attaching sidewalls and ceiling panels. The facility is accessible from all sides and even with the compact design there is adequate space to make modifications, repairs or overhauls. The Saugbrugs plant is Pentair’s first project in Scandinavia and marks another important milestone for the company.