Residual heat as a renewable energy source

Stora Enso Langerbrugge annually produces 550,000 tonnes of recycled paper for newspapers and magazines based on Paper for Recycling, or waste paper. The mill also has two high-performance bio combined heat and power (CHP) power plants, which not only supply all the process steam required, but also provide more than 70% of its electricity needs.

They wanted to utilise the excess residual heat released in the process via an underground heat network in collaboration with Volvo Cars Gent. This allowed Volvo to efficiently use the residual heat for their production processes and significantly reduce fossil energy consumption.

Our team prepared a preliminary design for the heat network, which served as a basis for further development. We also compiled the complete permit file and integrated the local authorities' requirements into the project design. We then produced a detailed technical design of the heat grid (4 km long in total), including determining the route of the pipeline under the Ghent-Terneuzen canal with possible extensions into the future. 

The heat network makes smart use of two Stora Enso bio-CHP plants, which convert internal sludge and external biomass into electricity and process heat. This generated energy heats water up to 135°C, which is then transported via an underground pipeline to Volvo Cars Gent to reach the desired temperature in the buildings and spray booths. The cooled water returns to Stora Enso, where it is reheated. 

Our team drafted the project's technical specifications and tender documents. We evaluated the bids received to select the best contractor meeting the specified requirements and quality standards. During the implementation phase of the project, we also provided site supervision including approval of technical sheets and the measurement records.