ESiTI – Wastewater treatment plant of the future: energy storage in interaction with technical infrastructure is as a trade-off between energy production and consumption

The ESiTI joint research project funded by the Federal Ministry of Education and Research (BMBF) is therefore pursuing the goal of developing a planning tool to increase the flexibility of energy flows in wastewater treatment plants. The partners are investigating how to increase the flexibility of energy flows based on technical, ecological, economic and social aspects. Sewage sludge treatment is a particular, since this both consumes energy and also produces and stores energy via digestion of the sludge to biogas.

In the framework of this project, Fraunhofer IGB researchers investigated the extent to which high-load digestion with and without microfiltration can be operated flexibly, when needed, without affecting the actual function. Tests at a lab-scale plant showed that applied impact loads and temperature changes (minimum 32 °C, maximum 43 °C) resulted in only slight reduction of digestion rate and digester gas production but not a failure of the digestion process.