Often a lot of waste heat in industry is completely or partially dissipated into the environment while there is still need for process heat in the form of warm or hot water, low pressure steam or warm air etc. By using heat pumps, waste heat can be upgraded to a higher temperature level. Even though heat pumps are long known, they can be rarely found in industrial environment. The maximum output temperature of approximately 80 to 90°C and the unfavourable electricity/fuel price ration are predominant reasons for the lack of heat pump applications in industry.

The project shows the economical use of heat pumps in industrial environment. A new technology (high temperature heat pump – HT HP) is developed, aiming at upgrading process heat by the use of unavoidable waste heat. Making this available it could be a key technology to decrease the excess of waste heat into the environment and to reduce the energy demand for energy-intensive industries like pulp and paper, food, brick, chemical and textile.

The development of the high temperature heat pump is the main goal of the project, which includes the selection of suitable working fluids, the definition of a proper cycle architecture, the retrofitting of an existing compressor to make it compatible with high temperature operation, the optimisation of heat exchangers and the elaboration of economical compressor driving technologies.

Upgrading waste heat to process heat gives industry the opportunity to achieve higher process temperatures at constant or lower production costs. For the paper industry processes will be developed to create a suitable process environment for integrating the heat pump technology. The aim of that process development is to investigate the influence of higher process temperatures on process optimisation, product quality, and production costs.
In the frame of this project a model installation is developed which allows the using of straw as a basic raw material for the substantial and energetic utilisation. In the process the motor cooling water (90°C) of a combine d heat and power plants (CHP - Plants) is to be used alternatively for a straw decomposition process at a temperature of 140°C or for a double stage vacuum evaporator (110°C) to recover process water.