Increasing Energy Efficiency in Pulp and Paper Production by Employing a New Type of Latent Heat Storage

In pulp and paper production black liquor is burnt to recover base chemicals and to generate electricity and steam which is e.g. used in papermaking machines. In the event of paper tearing excess steam has to be condensed usually. We propose a latent thermal energy system to recover that energy and re-use it in the papermaking machines. A storage model was developed and experimentally verified by a lab-scale prototype. For the specific process, we designed a tube-bundle storage using thermally conductive HDPE as PCM and show that up to 30 MWh can be recovered per day. Finally, we describe the potential of storages to improve energy generation and efficiency in plants.