Reactive fluids to intensify thermal energy conversion – REACHER

Thermal engines, refrigeration systems and heat pumps rely on thermodynamic cycles, in which an inert working fluid converts input thermal and mechanical energies into another useful energy form (work or heat) by cyclically transforming its thermal energy content. Although the selection of the working fluid is the main lever to increase performances of thermodynamic cycles, recorded efficiencies remain far below the highest achievable ones, whatever the fluid is. This deficiency strongly affects the exploitation of waste heat and renewable thermal energies by closed power cycles, and represents the main cause of the slow performance improvement of heat pumps and cooling technologies.
With the aim to effectively increase the performances of thermodynamic cycles, I propose to investigate a radically new thermodynamic structure, resulting from the use of equilibrated reactive working fluids instead of inert ones. Preliminary calculations have indeed shown that the simultaneous conversion of the thermal and chemical energy of reactive fluids may result in the intensification of these energy conversion processes, substantially increasing the efficiency and reducing the size of any energy conversion technology based on thermodynamic cycles. In particular, REACHER aims to overcome the main issue that currently prevents me to demonstrate the -theoretically sampled- potentiality of this new energy conversion concept. This issue lies in the uncertain availability thermodynamically and kinetically suitable reactions.
Searching for suitable reactive working fluids requires the challenging involvement of multiple disciplines: Physics (fluid thermodynamics and molecular physics), Chemistry (kinetics and reaction design), Energy Process Engineering (design of thermodynamic cycles), Mathematics (mathematical formulation of the whole optimisation problem), Informatics (definition of stable algorithms to solve reactive flash, implementation of optimisation and machine learning algorithms).
Probably due to the complex multi-disciplinarity of the problem or to the negligence of this possible way to convert chemical energy in thermodynamic cycles, this field has remained substantially unexplored.
REACHER seeks to the achievement of a two-level target: the design of equilibrated reactive fluids, by means of an original thermodynamic and kinetic predictive methodology making use of Group Contribution methods, Quantum Chemistry-based Computational Aided Molecular Design and Machine Learning, (primary level target), in order to allow the exploration of a new energy science domain, based on the exploitation of chemical energy in closed thermodynamic cycles (secondary level target).
REACHER’s methodology consists of three phases. Firstly, a thermodynamic predictive computational tool will be developed, that will be necessary for the realization of the further phases of the project. Then, thermodynamically and kinetically suitable reactions will be searched, designed and characterized. Finally, on the basis of that list of fluids and by means of the thermodynamic tool developed initially, the last phase implements a methodology to optimize the architecture of thermodynamic cycles operating with those fluids.
The successful development of REACHER will provide the fundamental understanding on how chemical energy can be efficiently exploited in the intensification of thermodynamic cycles for power, refrigeration and heating purposes. If the expected performances of analysed thermo-chemical cycles are confirmed, the outcomes of this project will allow the enhanced exploitation of available waste heat and renewable thermal energy sources, by means of small size and efficient machines.