Waste heat recovery for industrial heat intensive processes

Project Information

Hot chips

Grant agreement ID: 805689

DOI 10.3030/805689

Project closed

EC signature date 13 April 2018

Start date 1 May 2018

End date 30 April 2022

Funded under

• INDUSTRIAL LEADERSHIP - Leadership in enabling and industrial technologies - Information and Communication Technologies (ICT)

Total cost € 3 944 847,50

EU contribution € 2 500 000,00

Coordinated by

TOCIRCLE POWER SYSTEMS AS
Norway

Periodic Reporting for period 3 - Hot chips (Waste heat recovery for industrial heat intensive processes)

Reporting period: 2020-11-01 to 2022-04-30

Summary of the context and overall objectives of the project

What is the problem/issue being addressed?
More than 50% of all power generated in the World is lost to the environment as waste heat. Heat for frying, drying, sterilizing, cooking of pasteurizing is most of the time delivered by boilers burning fossil fuel.
Many such processes are operated 24/7, all year round. Heat generation constitutes a significant part of the overall production cost and adds to the industry’s negative environmental impact.
Heat pumps, recovering waste heat from a process and upgrading it to a higher temperature to make it usable again, are widely used in industry. Even if technical improvements have been lately observed, such heat pumps have until now not been able to efficiently deliver output temperatures above 140°C. It doesn't meet the requirements of many industrial processes e.g. deep-frying processes in the food manufacturing industry require temperatures approaching 200°C.
Duynie Group, a Dutch agritech company, has patented a high temperature heat pump design for waste heat recovery in deep frying processes, particularly for the production of French fries or potato chips. Tocircle’s proprietary compressor technology is the key equipment of this heat pump design.
Deep frying of potato is a first, well defined application which will be used within the present project to test Tocircle’s compressors in a real industrial environment, bringing the technology from TRL 6 to TRL 9 (Technology Readiness Level). There are however many other similar applications in the food industry, in the production of pharmaceutical products and chemistry, that can be addressed by this high temperature heat pump technology.
The issue being addressed is thus waste heat reconditioning in high temperature (160-190°C), heat intensive industrial production processes. Reconditioning meaning that the thermal energy contained in waste heat from the process is upgraded to the original temperature that the process requires.

Why is it important for society?
Increasing the energy efficiency of such continuous heat-intensive industrial processes allow reducing the energy cost involved and the impact on the environment. It has several positive consequences: potentially cheaper products for the consumer, lower carbon emissions, and finally better Corporate Social Responsibility (CSR) image for the producer.
Achieving better use of the energy consumed in continuous industrial processes (often running at full power in excess of 8000 hours per year) has potentially a much higher lifecycle value than solar or wind energy, which only generate at full rating during a few thousand hours annually.
Potato frying in Europe requires alone 8TWh of energy per year and releases 1.5 million tons of CO2.


What are the overall objectives?
The primary technical objective of the “Hot Chips” project is to verify the performance of Tocircle’s controllable rotary vane compressors in real conditions, in a full-scale high temperature heat pump for waste heat recovery in industrial deep-frying.
The commercial objective is to deploy the technology in many production sites in Europe.
The main environmental objective is to considerably reduce the carbon footprint of industrial heat intensive high temperature production processes, replacing up to 70% of gas consumption by electrical energy (ideally from renewable sources). Moreover, the working medium used in the heat pump shall be environmentally friendly, having zero ODP and zero GWP.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

Work performed
A scaled-down Pilot heat pump process skid (DTC-1500) was installed at Tocircle’s test center in Glomfjord in May 2018. This skid allowed an earlier start of testing of both heat pump functionalities and compressor performance.
The compressor assembly for the Pilot heat pump has been completed and the heat pump skid has been commissioned with water as working medium. Durability issues in the 2nd stage compressor were identified, which has led to design optimizations and production of an enhanced high pressure compressor unit. The DTC-1500 design has been optimized for successful stable operations. It has been running with the compressor stages 1 and 2 individually, and with both compressor stages together.

Main results
- Identified durability issues for the 2nd stage compressor, leading to design changes and fabrication of a prototype unit delivered in April 2019.
- Achieved full operation of the heat pump with both compressor stages running.
- Achieved delivery of 12 bara steam and 188 degC in condenser.
- Demonstrated evaporative compression (injection of liquid into the compressor working chamber, evaporating the liquid to avoid superheating the working fluid).
- Improved performance to 45% of Carnot (ideal) COP with stage 1 compressor.
- Extensive R&D work to qualify compressors for pilot operation has given valuable input to design of new generation compressors.
- Initiated preparations for installation of the scaled-down Pilot heat pump in a designated French fries production facility in Belgium.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

Progress
The compressor technology has been developed through the project and its function, performance and liquid tolerance has been thoroughly demonstrated. The concept of evaporative compression (ECT), in which liquified working fluid is injected directly into the compressors working chamber to evaporate during compression and maintain the working fluid in the two-phase region throughout the compression has been proven to work well. A unique innovation in which this liquid is injected through hydrostatic linear bearings to provide support for the moving vanes in the machine has been refined through the project to a working solution.

Expected results
After operating the heat pump in Tocircle’s facilities in Glomfjord (Norway) for app. one year, the complete system was shipped to the original HTHP manufacturer for necessary work/retrofit before installation in a production plant in Belgium. This work was aborted, for several reasons; one being an unforeseen increase in the costs involved. To justify this additional cost, the compressor performance and reliability had to be improved.
Improving the performance and reliability of the existing compressor technology was time consuming and complex. However, the design of a new generation compressor was already initiated, based on valuable key learning from Hot Chips. The first prototype of this new generation compressor has a capacity matching the Hot Chips pilot heat pump 2’nd compressor stage.
The new generation compressor has been successfully run both in the Hot Chips pilot HP in Glomfjord and in a separate open-loop heat pump system (MVR) designed and built by Tocircle. The compressor and MVR system were installed and successfully operated in a live client’s process in 2022.
The cooperation with Duynie remains relevant. Integration of the new generation compressor the HTHP is still an option and both partners are also exploring the possibility of using the Tocircle’s proprietary MVR system to recover the waste heat from the potato fryers.
The Hot Chips project has provided valuable insights in both markets and technical challenges related to high temperature heat pumps and compressors, and has opened doors to the new generation high-temperature heat pump technology to be leveraged by French fries producers and many others.

Testing of DTC-1500 pilot heat pump at Tocircle's Glomfjord test site

Tocircle's proprietary open-loop heat pump (MVR-400)

DTC-1500 Heat pumnp process part - Free in-kind contribution by Duynie Group BV

TC-C920 compressor on DTC-1500 Pilot heat pump