Optimizing the utilization of excess heat for district heating in a chipboard production plant

The industry is responsible for about one third of the global energy consumption, and thus, reducing energy and emissions in this sector is crucial to reach global climate goals. Methods like operational optimization can improve industrial processes' efficiency, leading to a decrease of excess heat or total energy. By combining operational optimization with flexibility measures like thermal energy storage, intermittent heat can be optimally utilized. This work analyzes the optimal utilization of excess heat for district heating in a real-world industrial use case, a chipboard production plant. The process includes a combined heat and power unit and units for production. Electricity can be sold to the grid, and two district heating demands need to be met while satisfying the production schedule of the plant. To exploit the utilization of excess heat, four adaptations to the process are considered: Increased district heating feed-in capacities, the integration of two different thermal energy storages, and the activation of an additional heat exchanger for district heating. To optimize the process's operation with and without the adaptations, an optimization framework is developed. Its modular structure allows for straight-forward design adaptations. The outcomes show that the process's efficiency can be significantly improved by applying operational optimization and considering the process adaptations. In all scenarios, the currently contracted district heating feed-in capacity can be significantly increased, leading to profits up to 108,000 _ per month and reduction of energy losses up to 87 %. Although the heat exchanger's activation yields the highest profits of all scenarios, thermal energy storages can increase the process's flexibility. In the end, the decision, which modification is most viable depends on the operator's objectives.

Automated summary

The industry accounts for about one third of global energy consumption, making it crucial to reduce energy consumption and emissions to achieve global climate goals. Operational optimization and flexibility measures can improve industrial processes efficiency, utilizing excess heat to decrease energy losses. By analyzing the optimal utilization of excess heat for district heating in a chipboard production plant, it was found that profits can be significantly increased by applying operational optimization and considering process adaptations.