Carboxylic acids as REAcTIVE refrigerants to make heat pumps efficient

Introduction

Aiming to contribute to a substantial increase in the sustainability of thermal power plants, heat pumps, and climatization systems, the ERC-StG-REACHER is introducing new working fluids for the thermodynamic cycle underlying these systems.

New Working Fluids

These new fluids are mixtures of dimers “A2” and monomers “A” undergoing a reversible dimerization reaction, A2 ⇄ 2 A, evolving instantaneously and spontaneously in the unit operations of the machine. REACHER has introduced about 200 of these reactive fluids.

Promising Candidates

Among them, the family of carboxylic acids (e.g., formic, acetic, propionic acid) seems very promising as working fluids for residential heat pumps. Other than having excellent environmental properties, their use promises an outstanding 17-43% relative efficiency improvement compared to state-of-the-art heat pumps.

Main Objective

In this context, the main objective of the ERC-PoC-CREATIVE is to perform the first step towards the realization of a residential heat pump prototype operating with formic acid, enabling the validation of the theoretically observed positive chemical reaction effects.

Preliminary Steps

This step consists of preliminarily verifying the feasible compression of formic acid with a finely controlled series of available compression technologies, using air as the working fluid in the sub-atmospheric pressure conditions characterizing operation with formic acid.

Future Developments

Within CREATIVE, these results will further allow the design of a pilot operating with formic acid to test, in a future PoC, the compressors preliminarily selected and pre-tested with air.

Experimental Setups

The realization and design of the experimental setups for the formic acid compression feasibility assessment are supported by thermodynamic calculations carried out in CREATIVE, using tools developed in REACHER.

Support and Collaboration

This PoC is supported by the expertise of two industrial partners and involves the Host Institution’s Technology Transfer Office, which will handle IP management and explore valorization pathways for the key exploitable results.