PAC-HT: a project for decarbonised heat pumps up to 150°C

A significant part of the energy consumed by industry is used in the form of heat in various processes such as drying, sterilisation, material processing, distillation, etc. With its high energy consumption, too often accompanied by high CO2 emissions, how can heat production be decarbonised? Interview with Clément Gachot, in charge of an EDF R&D project that aims to develop innovative heat pumps, adapted to industrial processes.

Clément Gachot

"Heat pumps are currently very little used in industry, particularly when it comes to temperatures over 80°C. Yet a significant part of industrial needs lie in the 80-150 °C range, and heat pumps are cost-effective, efficient, and have lower carbon emissions than gas or oil-fired boilers. In addition, they can make use of waste heat, which represents about half of the thermal energy consumed on industrial sites”, notes Clément Gachot, project manager for the “Low Carbon heating and cooling production and distribution solution(SoBasCarbone) at EDF R&D. This finding led the project team to work in partnership with manufacturers to develop new high-temperature heat pumps, capable of reaching up to 150°C.

Huge opportunities with multiple industrial constraints to be overcome

"The latest report by the International Energy Agency (IEA) on global carbon neutrality by 2050 shows that sif we want to meet this target, 500 heat pumps per month must be deployed in light industry worldwide over the next 30 years. In addition to being a great opportunity for EDF Group, replacing gas or oil-fired boilers with electrical systems and more specifically heat pumps is an extremely efficient way to decarbonise industry, due to the coefficient of performance of heat pumps observed in the laboratory under real operating conditions of between 3 and 5 depending on the case”, explains the project manager. Heat pumps – which start by taking available waste heat and transferring it to the flow to be heated – can produce 1MWh thermal from 250kWh of electrical energy plus 750kWh of waste heat recovered for free.

So why has industry not adopted heat pumps on a large scale?

First of all, because the time for return on investment is considered too long by manufacturers, who remain cautious in their investment choices. Then, the processes in place use boilers with circuits historically sized to suit them. Changing the means of production and recovering waste heat thus requires a significant investment, which enters into the overall economic balance of the operation. In addition, for high temperatures (>80°C), machine manufacturers offer few or no solutions, particularly for temperatures above 120°C. Finally, industry is used to using steam, an efficient energy carrier, for its processes: and it has to be said that most heat pumps on the market use liquid water or air as the carrier. We must therefore step up our collaborations and partnerships with manufacturers to offer heat pumps adapted to the needs of industry, support our entities in order to propose competitive projects to customers and provide support, to Dalkia in particular, in guaranteeing the promised energy performance over time”. This is the threefold goal of the SoBasCarbone project in working towards a CO2-neutral future.

The laboratory and technologies developed by EDF Group R&D has been working for many years on the development of high-temperature heat pump prototypes that meet industry’s expectations in its dedicated laboratory on the EDF Lab site, Les Renardières (77). Some have already been deployed on industrial sites and others will be soon. TRANSPAC, a unique, high-performance, transcritical heat pump, that can significantly improve the coefficient of performance and heat air at 140°C, will see its first full-scale prototype deployed on a drying process in the paper industry in collaboration with Dalkia. In addition, PACO, an innovative high-temperature heat pump operating with the thermodynamic cycle of water to overcome the refrigerant fluid problem (flammability, impact on the ozone layer, etc.) and producing hot water or steam at 130°C, has been developed in collaboration with Johnson Controls and can be deployed for distillation processes, for example. Finally, EDF R&D is developing, in particular through the European Bamboo project, a heat pump concept producing steam, with a first laboratory demonstration planned in 2022.