Development of heat pump for drying plastic granules

Plastic production is an energy intensive process with a high level of heating and cooling demand. Denmark's goal of achieving a future energy system based solely on renewable energy by 2050 is drawing attention of plastic industry towards shifting from pure economic emphasizing to both economic and sustainability emphasis (optimization of energy and reduction of wastes) in this sector. Energy management of the drying process can play a significant role in this regard.

In this project, a process that uses electricity directly for both heating and cooling will be converted to an integrated solution, where the supplied energy in the form of electricity is minimized by both recovering heat from injection molding machine and using a heat pump to supply heat at high temperatures up to 90 °C to the plastic granulate dryer.

Heat pumps are highly efficient, however, there is a need for a low cost, small capacity heat pump systems that can be easily integrated and adapted to the required condition of the dryer of plastic granulate and injection molding machine with low GWP, ODP refrigerant and high COP.

The project includes detailed analysis of the integration process at the production plant of the end-user, representing a plastic industry. Using this case as a starting point will provide a possibility of transition towards electrification of plastic industry, significant increase of the efficiency and reduction of energy demand and CO2 emission in this sector.

In collaboration between industries, suppliers, consultants and research, specific solutions are formulated for efficient process integration and specifications of new equipment, which makes this transformation possible.