Industry: Green prototype for cutting business costs of food pasteurization

ENEA has created a low environmental impact prototype for the pasteurization of food in small sized plants, capable of cutting energy consumption by 70% in the heating phase of the process and by 42% over the entire cycle, as compared with conventional systems.

It’s the innovative system PA.CO2 (PAsteurization with CO₂) which employs CO₂ as a refrigerant and uses the energy of air or water thanks to a reversible heat pump which is capable of either heating or cooling the fluid.

The pasteurization process, the main heat treatment used to destroy pathogenic organisms present in foods such as milk, beer, wine, fruit juices, eggs and preserves, consists of three phases: heating - which requires keeping food for 15-30 minutes at temperatures up to 85 ° C , cooling and preservation of the food mixture.

"The small and medium-sized pasteurisers perform the post-pasteurization cooling and conservation phases with a standard refrigerating cycle, while the heating phase, i.e the pasteurization itself, is carried out with appropriate electrical resistances, which strongly affect the overall energy consumption ", Raniero Trinchieri of the ENEA Laboratory Development of Chemical  and Thermo-Fluid Dynamics Processes for Energy, said. “Reversible heat pumps can be used in pasteurization with benefits both in terms of efficiency and energy savings, as well as environmental compatibility, since the working principle can guarantee a useful effect in heating, superior to the electric power absorbed", Trinchieri concluded.

PA.CO2 has also been equipped with an innovative control system, which optimizes the thermodynamic cycle in all operating conditions and makes it possible to make the entire pasteurisation process more efficient, with total energy savings of over 3 kWh per cycle .

"The added value of innovation lies in the fact that part of the energy transferred comes from a renewable source, being extracted from the thermal source, air or water. The use of a low environmental impact refrigerant such as CO₂ is not subject to the restrictions imposed by recent regulations on the marketing of synthetic equivalents ", Luca Saraceno, researcher at the ENEA laboratory, pointed out. "Furthermore, the working fluid can reach temperatures considerably higher than those obtained with conventional technologies, thus allowing to carry out pasteurization with shorter times and lower consumption", Saraceno concluded.

In order to confirm the performance estimates and analyze new calculation models that demonstrate further reductions in energy requirements up to 15%, but also expand the application areas of innovation, in the coming months the researchers will perform new tests as part of a new experimental phase whose results are expected for 2019.

For more information please contact:

Raniero Trinchieri - ENEA, Laboratory Development of Chemical  and Thermo-Fluid Dynamics Processes for Energy - raniero.trinchieri@enea.it –

Luca Saraceno - ENEA, Laboratory Development of Chemical  and Thermo-Fluid Dynamics Processes for Energy- luca.saraceno@enea.it