Project description

Process water at Papierfabriek Doetinchem is being reused internally several times, resulting in residual water concentrated with organic matter. This residual water of 35°C is pumped to a new sewage treatment plant via a dedicated 4.5 kilometer pressure pipe. At this plant, at the site of the local water board, biogas is produced from the wastewater and combined with the biogas that is produced by a sludge digester of the water board. The biogas is returned to the paper mill via the same route and/or processed into green gas and supplied to the local natural gas network. That’s what we call innovation!

Project purpose

The biogas produced is used to replace natural gas for steam production and for consumption by households. The aim of the project is to get as high as possible in the sustainability pyramid in the smartest way possible. This process total process became significantly more energy efficient. For example, electricity was previously used to remove organic matter from the water; now it is the exact opposite. The sustainable treatment of the residual water saves 2,300 tonnes of CO2 annually, which is comparable to the natural gas consumption of one thousand households.

Project evaluation

The industrial water treatment plant in Etten, which opened in October 2022, is a wonderful example of industrial symbiosis. The expertise, facilities and resources of a municipal waste water treatment is smartly combined with the both the biogas potential of residual water and the renewable energy needs of a paper mill, via a joint investment in digestion equipment and pipelines.