MAGENTA

Today, thermal loss amounts to as much as 20-50% of total energy consumption across different industrial sectors. Therefore, if even a small fraction of ‘waste-heat’ can be converted into more useful forms of energy such as electricity, it would lead to reducing considerable amount of energy consumption and to boosting industrial competitiveness. Thermoelectric (TE) materials that are capable of converting heat into electricity have been long considered as a possible solution to recover the low-grade waste-heat from industrial waste-stream, motor engines, household electronic appliances or body-heat. Solid semiconductor-based TE-modules were the first to enter the commercial application, and they still dominate the TE-market today. Despite their technical robustness including long life-time, simple usage involving no moving parts, TE-technology has long been limited mostly to small-power applications due to their low efficiency. Nanotechnology (nano-structuration) of TE materials has led to remarkable improvements in TE-energy conversion capacity in the past 20 years. However, the most promising materials reported in the literature are yet to enter a wide-scale commercial deployment, partly due to their small sizes, substantial production costs and the use of scarce and/or toxic raw materials.

MAGENTA develops brand new thermoelectric materials based on ionic ferrofluids; i.e., colloidal dispersions of magnetic nanoparticles in ionic liquids. It is an inter-disciplinary and cross-sector R&D project combining concepts and techniques from physics, chemistry and electrochemistry with an active participation from industrial partners. As its final products, MAGENTA will offer novel liquid thermoelectric materials that are versatile, cost-effective and non-toxic to assist the economically and environmentally sustainable energy transition in Europe. The lead-user industries targeted by MAGENTA are automobile and microelectronic sectors, but demonstration-type thermoelectric generators will also be produced for public outreach actions on waste-heat recovery technologies.

The following video reports an additional description of the project by our scientific partners.

Consortium as a whole

MAGENTA is coordinated by CEA, the French Alternative Energies and Atomic Energy Commission. MAGENTA brings together a large and diverse array of partners each contributing to a common goal of fostering an innovative ecosystem around a new line of renewable energy (thermoelectric) technology. As the project’s aims cover a wide range of objectives starting from establishing foundational knowledge behind the novel TE phenomena in ferrofluids, developing magneto-TE-devices and materials for waste-heat recovery in targeted applications (automobiles and microelectronics) and to public engagement in the future renewable energy technology, the MAGENTA consortium is highly interdisciplinary.

Our role

Every modern vehicle equipped with an internal combustion engine (ICE) loses about 25-30% of the fuel energy as the heat is dissipated in exhaust gases. The temperature of the gases downstream to the engine has a medium value of 400-500 °C with peaks at 700 °C, so it is a high temperature source that can be used to feed thermodynamic cycles. In the transportation industry, exhaust heat recovery with thermoelectric generator (TEG) is being developed by several automotive OEMs using solid-state materials.

In MAGENTA, a first of its kind automotive TEG prototype is designed to demonstrate thermal-to-electric energy conversion capacity of ionic liquids for recovering heat from the exhaust gases of internal combustion engines. Gemmate Technologies leads a ICE-specific feasibility analysis (cell materials stability, dimensions, efficiency, etc.) in a well-defined operational condition and extensively scrutinized prior to the design, construction and integration phases. Gemmate Technologies cooperates to develop the TEG which is conceived to be integrated in the exhaust line of a normal production vehicle. To demonstrate the system in a configuration that is representative of a unit for automotive applications, the TEG is conceived as a stand-alone unit starting from the specifications and requirements defined in the feasibility analysis. The TEG is composed by an inlet and outlet manifolds connected to the exhaust gas pipeline, a heat exchanger able to collect heat from the exhaust fumes, a colloing circuit, and a stack of thermoelectric cells based on the ionic ferrofluid technology.

 

Thermoelectric systems require heat exchangers on both the hot and cold sides of the device. The heat exchangers enable sufficient heat transfer from the heat source to the thermoelectrical cell hot side as well as heat rejection or cooling on the cold side. Therefore, the effectiveness of the heat exchangers directly impacts the temperature drop across the thermocell. The overall heat transfer capability of the heat exchanger depends on the exchanger design and material as well as the heat exchange fluid.

The integration of the generator in the engine exhaust pipeline is simulated using commercial computational fluid dynamics and multi-physics codes. The simulations results are used to guide the design of the different components of the prototype also considering their manufacturing complexity and costs. An excerpt of the simulated parameters used in the generator design are reported as follow.

 

The manufacturing of the components and their assembly are performed following a modular approach as shown in the video below filmed by our industrial partner.

Scientific publications

From Academia to Industry: Criteria for Upscaling Ionic Liquid-Based Thermo-Electrochemical Cells for Large-Scale Applications, Energies 2024, 17(1), 1; https://doi.org/10.3390/en17010001