Research on the Use of Potassium Formate in the Indirect Contact Freezing System Used in Food Preservation

Abstract

Low-temperature contact freezing refrigeration solutions available on the market typically contain refrigerants inside the plates, which may result in harmful emissions into the atmosphere and the contamination of food products in case of failure. However, a concept for a refrigeration plant with new coolant—a solution of potassium formate—is introduced in this paper. It comprises two systems: the primary one, where the compressor system is cooling down the coolant in the evaporator (as a heat and mass exchanger), and the secondary one, where the pump system is responsible for coolant circulation. As a coolant in the intermediate system, a 48% aqueous solution of potassium formate was utilized due to its numerous benefits. This liquid is neutral to the pump circuit installation materials and does not pose a threat to the food product in case of leakage, as it is also used as a food preservative additive. The use of liquid coolant ensures that any malfunction results in a visible leak, allowing for prompt intervention, unlike refrigerants that escape unnoticed into the atmosphere. Moreover, a refrigerant with a lower GWP than traditional solutions was chosen, making the system more eco-friendly.